NEET Biology

NEET Biology Animal Nutrition And Digestive System

Nutrition: Nutrition is the procurement of substances termed nutrients necessary for growth, maintenance and providing energy to carry out synthetic activities of living bodies.

Nutrition is of two types :

1. Autotrophic mode of nutrition.
2. Heterotrophic mode of nutrition.

Autotrophic Nutrition. Mostly green plants can manufacture their organic food due to the presence of chlorophyll. They take up CO₂ and H₂O and manufacture carbohydrates in the presence of sunlight.

• Such organisms are called autotrophs and their mode of nutrition is called autotrophic. Organisms may be photoautotrophs Example, green plants. Euglena or chemoautotrophs, For Example, sulphur bacteria, nitrite bacteria etc.

Heterotrophic nutrition. In this type of mode of nutrition, the animals derive organic food materials by consuming bodies or products of other living or dead plants or animals. Heterotrophs may be holozoic, saprozoic or parasitic.

Myxotrophic nutrition. They carry out autotrophic as well as saprotrophic nutrition Example: Euglena.

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NEET Biology Animal Nutrition And Digestive System Notes

NEET Biology Animal Nutrition and Digestive System Modes of Animal Nutrition

Based on food, heterotrophic animals are classified into the following categories :

1. Herbivorous. These animals (herbivores) feed exclusively on plants Example, cows, horses, sheep, and rabbits.
2. Carnivorous. Carnivore animals kill and feed upon the flesh of other animals Example. lion, tiger, wolves.
3. Omnivorous. These animals feed on both plants and animals Example. man, cockroach, Pig-
4. Carrion eaters. They feed on dead animals, also termed scavengers Example., Hyaena, Neltura, Kites etc.
5. Fruitivorous animals feed on fruit and fruit juices, Example. Honey bees, and squirrels.
6. Insectivorous animals eat insects as food Example, Frog and wall lizard.
7. Sanguivorous animals are blood-sucking Examples, are leeches, body lice, and bed bugs.
8. Cannibolus organisms devour their species Example, cockroaches, some fishes, frogs and snakes.
9. Detritus. Animals feed chiefly upon organic matters present in the humus Example, earthworms.
10. Eggivorous. Eat eggs
11. Grainivorous Animals feed upon grains.
12. Soilivorous. Eat up the soil.

Animal Nutrition And Digestive System NEET Notes

NEET Biology Animal Nutrition and Digestive System Feeding Mechanism

Feeding mechanism in liquid feeders. (Fluid feeder)

1. Diffusion. Many parasitic organisms (protozoans, tapeworm) absorb the dissolved organic food through the body surface.
2. Bloodsucking. Their mouth parts are modified for sucking blood For Example. leeches, vampire bats and mosquitoes (piercing and sucking type of mouth parts).
3. Aphids suck plant sap.
4. Feeding mechanism in Microplmgous animals (Filter feeders). The food of such animals (paramecia, sponges, corals, bivalves, tadpoles, mosquito larvae) is suspended in water fluid and they possess filtering devices (clusters of pseudopodia, cilia, flagella, sheets of mucus).
5. The water current is drawn in and food is obtained.
6. Feeding mechanism in necrophagous animals. These animals feed on large plant or animal matter. Filters are absent. The methods of feeding are different in different animals.

• Amoeba has no mouth but ingests food with the help of pseudopodia. The process is called phagocytosis.
• Some animals like hydra have tentacles for capturing prey.
• Detritus feeders like earthworms suck solid organic food along with large quantities of soil.
• Frogs and toads have protrusible sticky tongues for capturing prey.
• Many animals apply their mouths directly to the food and use their teeth.

Primates including man carry the food with hands to mouth and teeth are special¬ized for biting, cutting, tearing, chewing and mastication. The tongue acts as a spoon for liquids. Their teeth jaw bones and muscles are well developed.

NEET Animal Nutrition And Digestive System Chapter Notes

NEET Biology Animal Nutrition and Digestive System Cockroach

Initially divided as foregut, midgut and hindgut.

1. Foregut (stomodaeum) ectodermal part, lined with cuticle divided into :
2. Buccal cavity and pharynx. The gut begins with a buccal cavity followed by a short pharynx.
3. Oesophagus. A narrow but longer tube-like part in the thorax.
4. Crop. The largest, thick-walled part, serves for storage of flood, digestion also occurs here but with the enzymes from the hepatic caeca.

• • Gizzard, (proventriculus) Thick walled, bulbous part with 6 cuticular teeth and a thick circular muscle layer, for grinding the food. From the lower part extends the secretory stomodaeal valve in the midgut to secrete the peritrophic membrane.
  • Midgut (or Mesenteron or ventriculus or stomach) A narrow tube of uniform diameter of endodermal origin. It is a true gut for digestion and absorption.
  • Food present in it is always covered by a peritrophic membrane, e 8-12 tube-like hepatic caeca demarcate the beginning of midgut as part of it.

Animal Nutrition And Digestive System NEET Notes

Hindgut (or Proctodaeum). Its junction with the mesenteron is marked by the presence of (60-150) Malpighian tubules the excretory organs.

• Relatively larger in diameter, it is divided into the ileum, colon and rectum.
• The cuticle lining of the ileum bears a minute spine which serves to break the peritrophic membrane.

The wall has six longitudinal fold, rectal papillae, for absorption of water.

NEET Biology Animal Nutrition And Digestive System Of Palaemon

The digestive system of Palaemon consists of an alimentary canal and a digestive gland, called hepatopancreas.

Alimentary Canal- The Alimentary canal is a straight tube and is distinguished into the following three parts :

1. Stomodaeum or foregut which comprises the mouth, buccal cavity, oesophagus and stomach.
2. Mesenteron or midgut which comprises the intestine.
3. Proclodacum or hindgut which comprises the rectum and the anus.

Animal Nutrition And Digestive System NEET Notes

The foregut and hindgut have an internal lining of the cuticle (intima) but the midgut is a soft lining of endoderm.

Foregut

1. Mouth. It is a longitudinal slit situated mid-ventrally in the third cephalic segment. The month is bounded by a shield-like Inbrum in front, bilobed labium behind and the incisor processes to mandible laterally. It leads into a short buccal cavity.
2. Huecal cavity. It is an anthem-posteriorly compressed small chamber. It has a thick chitmous lining which is turned into irregular folds. The molar processes or mandibles project into the buccal cavity and lie opposite to each other. These are used to crush the food between them.

1. Oesophagus. It is a short but broad tube which runs vertically upwards from the buccal cavity to the cardiac stomach. Internally the thick muscular walls of the oesophagus are thrown into four prominent longitudinal folds which project into its lumen.
2. Due to these folds, the lumen of the oesophagus assumes a star-shaped appearance.
3. Stomach. It is the largest part of the alimentary canal. It occupies most of the cephalorhoracic cavity. The stomach lies buried in the hepatopancreas, and it is covered over by the hepatopancreas laterally, posteriorly and ventrally.
4. The stomach is divided into two unequal chambers: the cardiac stomach and the pyloric stomach.

Cardiac stomach. It is a bag-like anterior chamber of the stomach. The internal chitinous lining (i.e., intima) of the cardiac stomach is thin and produced into numerous inconspicuous longitudinal folds covered by minute bristles. The wall of the stomach is supported by several calcified cuticular plates such as follows :

1. Circular plate
2. Lancevlate plate
3. Hastate plate
4. Combed plate
5. Lateral grooves and groove plates
6. Guiding ridges

Pyloric stomach. It is a very small narrow posterior chamber of the stomach. It lies below the posterior end of the cardiac stomach. Its lateral walls are thick and muscular.

• They divide the lumen of the pyloric stomach into a small dorsal chamber and a large ventral chamber. Both chambers are connected by a short narrow vertical slit-like apparture.
• Midgut It is a long, narrow, straight and slender tube which runs from the posterior part of the cephalothorax to the sixth abdominal segment. The midgut lies above the mass of the ventral abdominal muscles.

Hindgut. It extends from the posterior end of the midgut to the anus. It forms the shortest part of the alimentary canal. Anteriorly, the hindgut is swollen to a thick muscular sac, called the rectum while the posterior part is narrow and tubular which opens to the exterior through the. anus.

The rectum bears several thick longitudinal folds which project into the lumen of the hindgut. The rectum is lined internally by the chitinous cuticle.

Hepatopancreas. Die digestive gland, liver or hepatopancreas is a large bilobed, compact, orange-coloured gland which fills the cephalothoracic cavity. It surrounds the stomach and the anterior part of the midgut. Developmental!)’ it is formed from one pair of lateral tubular outgrowths, the hepatic caeca, of the midgut.

• The hepatopancreas of an adult consists of numerous glandular tubules which are branched in a resinous manner. These branches are held together by the connective tissue to form a compact mass. The wall of the tubules is formed of a single layer of columnar epithelium.
• This epithelium contains the following four types of cells. 1. granular cells; 2. ferment cells; 3, hepatic cells and -I. basal or replacing cells. All the epithelial cells rest on a basement membrane.
• Functions. The hepatopancreas functions like the liver, pancreas and small intestine of higher animals. It performs the following functions :
• Like the pancreas, it secretes digestive enzymes for the digestion of carbohydrates, fats and proteins. 2. Like the small intestine it absorbs digested food.

Like the liver. il serves as an important storage organ. It stores glycogen, fat and calcium. Some intracellular digestion also exists in its cells.

Food and Feeding: Polaemon is a nocturnal and omnivorous animal. It feeds on algae, mosses and other aquatic weeds. Occasionally, it feeds on small insects, snails, tadpoles, fishes, etc. and debris from the bottom.

The food is swallowed into the buccal cavity with the help of 1st pair of maxillipeds, maxillae and maxillulae. Inside the buccal cavity, food is masticated by the molar processes of mandibles.

Animal Nutrition And Digestive System NEET Notes

Digestion, Absorption and Egestion:

In Palaemon, the digestive process commences in the cardiac stomach.

• The hepatopancreas secretes enzymes into the pyloric stomach, from whence they travel to the cardiac stomach to combine with the food.
• The cardiac stomach alternately contracts and expands, facilitating the churning and enzymatic digestion of food.
• The undigested meal, containing unabsorbed material, ascends the dorsal chamber and proceeds into the midgut for absorption.
• The remaining digested food is absorbed in the midgut, while the residual faecal matter is sent to the hindgut and ultimately ejected through the anus.

Animal Nutrition And Digestive System Class 12 Notes For NEET

NEET Biology Animal Nutrition and Digestive System Of Vertebrates

The gut is divided only into functional parts not based on origin. The major parts are the mouth, pharynx, oesophagus, stomach, small intestine, large intestine and anus (or cloaca).

• It is longer in herbivores than carnivores.
• The major glands associated with it are the liver and pancreas.

Anatomy of Gut

Frog: Salivary glands are absent in frogs.

• The oesophagus is a short tube as a frog has no neck and thorax.
• The stomach is present in the middle of the body cavity and begins from the anterior part as a straight tube-like structure. Its posterior narrow pylorus makes ‘U with the duodenum, which lodges the pancreas.
• The small intestine is about 1-1.5 feet long.
• The large intestine is represented only by the rectum which opens into the cloaca.
  Rabbit (Mammals)
• The oesophagus is a long tube as that passes through the neck and thoracic cavity.
• The stomach is present in the left side of the abdominal cavity as a transverse bag-like structure and is roughly J-shaped.
• ‘U’ is formed by the duodenal loop only.
• The small intestine is about 4-5 feet long (giraffe = 250 ft).
• Sacculus rotundas act as a junction from which the caecum arises as a separate branch of the large intestine, as the site for cellulose digestion.
• Colon (50 cm) and rectum (75 cm) open into anus.

Ruminants. (for example cattle, sheep, goats, camel and deer) have a compound stomach with the following four chambers:

1. Rumen First and the largest part for the storage of food and digestion of cellulose by symbiotic bacteria living here (Kumcnococcus).
2. The reticulum (honeycomb) next chamber is also the site for cellulose digestion.
3. Omasum (psalterium)-concentrates the food by absorbing H₂O and H₃CO, (absent in camel and deer).
4. Abomasum or true stomach-last part is the secretion of gastric juice and digestion takes place here only. Camel’s rumen and reticulum have many diverticula (water pockets) but these do not store water.

Camel can live without water for two weeks. Its hump is a store of fats. For every 100 gms of fat metabolized, it produces 120 ml of H₂O.

NEET Biology Animal Nutrition And Digestive System Revision Notes

NEET Biology Animal Nutrition and Digestive System Parts Of the Digestive System

Parts of the alimentary canal of man.

1. Buccal Cavity
2. Pharynx
3. Oesophagus
4. Stomach
5. Small Intestine (Duodenum Jejunum, and Ileum)
6. Caecum and
7. Large Intestine (colon and rectum). It terminates at the anal opening.

Digestive Glands

1. Salivary glands
2. Gastric glands
3. Liver
4. Pancreas
5. Intestinal glands

Mouth Cavity: The mouth (oral or buccal cavity) is formed by cheeks, hard and soft palates and tongue.

1. The vestibule of die oral cavity is bounded externally by cheeks and lips and internally by gum and teeth.
2. The roof of the buccal cavity is the palate that separates it from the nasal chamber, consisting of hard and soft palate. The mucous epithelium has thick transverse folds called palatine rugae (thick in the case of carnivorous animals).
3. The terminal part of the soft palate hangs a fleshy ‘V’ shape in the throat called the uvula.

On either side of the uvula, tonsils are present that are made of lymphatic tissue.

Tongue: It is a thick, musculo-sensory organ.

1. Attached to the floor of the mouth by a soft ligamentous fold, the frenulum.
2. Covered by the mucous membrane of thick stratified squamous epithelium with papillae of 4 types.
3. The tongue is made up of striated muscles (voluntary).
4. The tongue possesses Nuhn’s glands (glandular lingual autistics).
5. Taste receptors (taste buds) are found mainly on the lingual papillae of the tongue.
6. Filiform: Most abundant short filamentous (absent in Rabbit),
7. Fungiform: Small mushroom-shaped on the upper part with taste buds.
8. Foliate: Small leaf-like folds on the lateral side.
9. Circumvallate: Largest cup-like, on the posterior part.

Animal Nutrition And Digestive System NEET Notes

NEET Biology Animal Nutrition and Digestive System Dentition and Structure of Tooth

Originated from ectoderm and mesoderm.

Dentition. The teeth are cone-shaped structures present in the mouth cavity. A full set of teeth in adult numbers 32 and child 20 represented by dental formula  2/2; c 1/1/; pm 2/ 2; m3/3 = 32 and  2/2: c 1/1: pm 0/0: m 2/2 = 20 respectively, as the teeth are heterodont initial represented by i-incisor. c-canine, pm-premolars and m-molar. The teeth of man are thecodont, and diphyodont. heterodont and bunodont.

Structure of tooth. The tooth is divisible into three parts-root, neck and crown. The root is lodged in the socket or alveolus of the jaw bone and is firmly fixed by a cement-like substance called cementum. The bulk of the tooth is composed of a hard ivory substance called dentine.

It encloses a pulp cavity containing soft pulp composed of adipose tissue, blood vessels and nerve fibres. The pulp cavity is lined by a layer of odontoblasts. The neck part of the tooth is firmly held by fleshy gum. The crown is covered by the hardest substance called enamel. The teeth help in cutting and mastication of food.

NEET Biology Animal Nutrition And Digestive System Revision Notes

NEET Biology Animal Nutrition and Digestive System Types of Teeth

1. Acrodont dentition. When the teeth are not embedded in sockets they are part of some bone as maxillary teeth and vomerine teeth of frogs.
2. Thecodont dentition. When teeth are separate entities and are embedded in the teeth sockets as in mammals and crocodiles.
3. Diphyodont dentition. When two sets of teeth are produced in the lifetime i.e. milk teeth and permanent teeth, as in Mammals.

1. Polyphyodnnt dentition. When teeth can be replaced many times in life as a frog.
2. Homodont Dentition (Isodont). When teeth are alike as in frog.
3. Heterodont Dentition . When there are different types of teeth present, like incisors canines, premolars and molars as in Mammals.
4. pleurodont  Dentition. When the sides of teeth are fixed over the lateral surface of jaws as in reptiles.
5. Bunodont Dentition. When there are low cusps present made by ridges of the teeth as in man,
6. Solenodont. When the cusps are present as in sheep, etc,
7. lophodont. When cusps fuse into transverse ridges as in elephants.
8. Secodont. In carnivores such as cats. dog. lion. etc. cusps are pointed and are used in cutting.
9. Crocodilian Teeth. Among the reptiles, crocodilians are exceptional in having theodont teeth. This suggests an evolutionary relationship between the reptiles and mammals.
10. Carnnssial Teeth. In many carnivores (dogs, cats), the last upper premolar and the first lower molar are modified for shearing flesh. They are large and bite on each other like a pair of scissors. They are also called sectorial or shearing teeth.
11. Eye Teeth. The upper canine is called eye teeth.

NEET Biology Animal Nutrition And Digestive System Important Points

NEET Biology Animal Nutrition and Digestive System Pharynx

The pharynx is about a 12 cm long vertical canal beyond the soft palate. The food and air passages cross here. The pharynx may be divided into 3 parts: nasopharynx, oropharynx and laryngopharynx.

Function. The function of the pharynx as a part of the digestive tract is merely to serve as a passageway for food from the oral cavity to the oesophagus. It has in its walls the voluntary muscles which start swallowing movements.

NEET Biology Animal Nutrition and Digestive System Oesophagus

Esophagus:

The esophagus is a 25 cm long, narrow, muscular, straight tube lined with stratified squamous epithelium containing mucous glands.

• It descends down the neck posterior to the trachea, traverses the thorax behind the heart, and passes through the diaphragm into the abdomen.
• Here, it sharply curves to enter the stomach. This bend is a mechanism to prevent the reflux of stomach contents into the oesophagus.
• Longitudinal folds maintain the cavity in a nearly closed state, except during the act of swallowing food.
• This monitors the air intake during respiration; the upper section of the oesophagus has striated muscle, the middle section contains a combination of striated and smooth muscle, while the lower section consists solely of smooth muscle.

Functionality:

The esophagus transmits food via peristalsis from the pharynx to the stomach.

Human Digestive System NEET Biology

NEET Biology Animal Nutrition and Digestive System Stomach

This stomach is wide, and J-shaped. distensible, muscular sac plated obliquely on the left side in the upper part of the abdomen just below the diaphragm. It is about 30. cm long and 15 cm wide. It has a greater curvature and a lesser curvature along its lower and upper sides.

The stomach is the most dilated part of the alimentary canal. In mammals, it is divided into three regions :

1. Cardiac stomach- Anterior
2. pyloric stomach-Posterior
3. Fundic stomach-Middle

The narrow central end of the stomach is called the pylorus.

• The fundic part of the stomach is absent.
• An empty stomach is lined with folds called rugae.
• Ruminant animals such as cattle, buffalo, sheep, goats and camel have a compound stomach.
• compound stomach consists of four chambers, rumen, reticulum, omasum and abomasum.
• Some ruminants like camel and deer do not have omasum.
• Rumen is the largest and first of (ho four chambers.
• The rumen and reticulum are the sites of cellulose digestion these harbour numerous bacteria and protozoa w which carry out extensive fermentation of cellulose.
• Cyclostomes and lobed fishes do not have stomachs.
• Omasum concentrates the food by absorbing water and bicarbonates.
• The fourth chamber, abomasum is the (rue stomach as it secretes gastric juice and HCL.
• From the abomasum, the food passes to the small intestine.

Functions of stomach

1. Temporary storage of food
2. Mechanical breakdown of food
3. Secretion of digestive juices.
4. Partial digestion of food.

NEET Biology Animal Nutrition And Digestive System Important Points

NEET Biology Animal Nutrition and Digestive System Intestine

The intestine is quite longer in mammals, about 13 feet in rabbits, and 22 feet long in men because such a length increases the scope of food absorption.

1. The intestine is usually longer in herbivores.
2. The wall of the intestine is provided with only involuntary muscles.
3. Small Intestine. The small intestine is a narrow tube, about 6 metres long in a living adult. It is the longest part of the alimentary canal. It comprises three parts: duodenum, jejunum and ileum.
4. duodenum. It follows the stomach. It is somewhat C-shaped and about 25 cm. long.
5. It receives the hepatopancreatic ampulla of the hepatopancreatic duct formed by the union of the bile duct and pancreatic duct.
6. Jejunum. The jejunum is the middle part of the small intestine. It follows the duodenum and is about 2-4 metres long. Its wall is thicker and more vascular than that of the ileum.
7. Ileum. The ileum forms the lower part of the small intestine. It is about 3-6 metres long and opens into the large intestine. Its wall is thinner and less vascular than that of the

Functions. The small intestine serves 2 main functions: completion of digestion and absorption of digested food. It also secretes some hormones such as cholecystokinin, secretin, duocrinin, and villikinin. entcrocrinin and enterogastrone.

NEET Biology Animal Nutrition and Digestive System Small Intestine

• In men, there is a common opening of the bile duct and pancreatic duct.
• Behind the duodenum is the jejunum, followed by the ileum.
• The lining of the small intestine bears a series of transverse folds called plicae circular or valves of Kerkering.
• Their internal lining is raised into innumerable minute finger-like processes called villi.
• In the wall of the small intestine, lymphatic tissues arc present collated Pcycr’s patches.
• Peyer’s patches are groups of lymph nodules that are most numerous in the ileum. They produce lymphocytes.
• The distal end of the ileum is expanded to form a small dilated spherical sac called sacculus rotundas in rabbits.
• The ileum opens into the caecum through an ileo-caccnl valve. large Intestine
• The large intestine is shorter than the small intestine. It is called the large intestine as it is wider than the small intestine. It is arranged around the mass of the small intestine.
• It is about 1-5 metres long. It lacks villi and microvilli. It shows three regions: caecum, colon and rectum.
• The caecum is very large and spacious in herbivores such as rabbit, horse and ass.
• The caecum of a rabbit is a thin-walled tube with peculiar external spiral constriction, which marks the presence of an internal spiral valve.
• Digestion of cellulose in rabbits takes place in caecum (Stomach in ruminants).
• Distally caecum terminates in a small, narrow, thick-walled tube vermiform appendix.
• But in man, the caecum is a reduced small pouch-like part below the opening of the ileum into the large intestine.
• In man, attached to the caecum is a twisted, coiled tube, measuring about 3 inches in length, called the vermiform appendix.
• The colon is thicker than the small intestine and thinner than the caecum. Constrictions of its wall form a series of small pockets called haustra.
• The haustra are arranged on either side of three median longitudinal muscle cords of the wall called taeniae.
• The colon of man is divided into ascending, transverse, descending and pelvic (sigmoid) portions.
• Mass peristalsis is initiated in the colon about half an hour after taking food.
• The pelvic colon continues into the rectum.
• The rectum is the last part of the alimentary canal, in man it is about 7-8 inches long.
• The terminal one inch of the rectum is called the anal canal and its exterior opening is called the anus.
• The Rectum of a rabbit is the narrow terminal part with faecal pellets present inside giving it a beaded appearance.

Human Digestive System NEET Biology

Functions. The large intestine mainly aids in the absorption of water; formation, temporary storage and elimination of faeces; and production of mucus for lubrication of mucosa.

• It also plays some role in digestion, absorption and excretion. The colon bacteria produce vitamins B and K which are absorbed.

NEET Biology Animal Nutrition And Digestive System Important Points

NEET Biology Animal Nutrition and Digestive System Digestive Glands

Salivary glands in humans 3 pairs in man, four pairs in rabbit, 5 pairs in rat and absent in frog. These are compound tubular-alveolar types.

Parotid gland

1. It is present near the ear (pinna).
2. It is the largest salivary gland but produces only  29% of saliva.
3. It contains the enzyme- Ptyalin (a-amylase). Ptyalin is lacking in predators, Example: Lion and Tiger.
4. The viral infection of these glands causes Mumps.
5. The secretion of these glands is poured into the buccal cavity through Slenson’s duct.

Submaxillary (submandibular) gland

1. It is present in the lower side of the upper jaw.
2. It produces- 70% of saliva secretion.
3. Its secretion reaches the buccal cavity through Wharton’s duct.

Sublingual gland

• It is present below the tongue.
• It is the smallest salivary gland and produces only 5% of the secretion
• Its secretion passes through the Duct of Rivins.

The salivary glands are absent in fishes, amphibians and aquatic  mammals,

Saliva -1.5 lit/day

1. pH – 6 to 7 (slightly acidic), on standing/heating it releases CO₂ and becomes alkaline.
2. The mucus of saliva helps in lubrication
3. Saliva also causes the denaturation of raw proteins without hydrolyzing them.
4. Thiocyanate ions, present in saliva, act as an antimicrobial agent to prevent infection by the microbes that often enter along with the food.
5. Saliva also has lysozymes.
6. Ptylain of saliva acts on boiled starch and converts it into maltose (a disaccharide).

NEET Biology Animal Nutrition And Digestive System Important Points

NEET Biology Animal Nutrition and Digestive System Liver

It is the largest sized, reddish-brown gland of the body. It is present in the posterior concavity of the diaphragm in the right upper part of the abdomen.

• The liver is a multilobulated gland. It is formed of two main and two small lobes. Two main lobes are the larger right and smaller left lobes, while two small lobes are the quadrate and caudate lobes.
• Each liver lobe is formed of hexagonal lobules surrounded by a connective tissue sheath called a Glisson capsule.
• Present on the lower surface of the right liver lobe, there is a thin-walled, pear-shaped sac, called the gall bladder. It stores the bile (about 60 ml) secreted by the liver.
• Bile is drained from the liver by a bile duct which is formed by the joining of a cystic duct from the gall bladder and a common hepatic duct from different liver lobes.
• Just near the duodenum, the bile and pancreatic ducts join to form the hepatopancreatic duct. The opening of the hepatopancreatic duct in the duodenum is guarded by a sphincter of Oddi. Daily secretion of bile is about 600-1200 ml.
• Bilirubin is formed by the daily destruction of haemoglobin due to the death of 1% RBC every day.

1. The human liver weighs about 1.5 to 2 kg. and is divided into 3 lobes
2. Glisson’s capsule, connective tissue sheath around each lobule, is a characteristic feature of mammals.
3. Kupffer’s cells are large phagocytic cells to remove unwanted substances or foreign material from the liver hence, also known as hepatic macrophages.
4. Hepatic capillaries arise from the cell level and unite to form the main hepatic duct emerging from each lobe to join the bile duct (ductus choledocus) which is also joined by the Cystic duct emerging from the gall bladder.
5. The cystic duct conducts bile to the gall bladder.
6. Opening of the bile duct in the duodenum is guarded by the sphincter of Oddi.
7. The gall bladder is a separate part associated with the liver for the storage and concentration of bile.
8. The gall bladder is a sac located along the underside of the liver.
9. The gall bladder is absent in birds, rats, whales and horses.
10. Gall bladder stores bile.

• Functions of Liver. The liver performs a variety of functions like synthesis, interconversions, storage, and secretion of various substances as follows:
• Glycogenesis. Extra glucose is converted to glycogen with the help of insulin and stored in this form either in the liver or in muscles.
• Glycogenolysis. Glycogen is converted into glucose when its level falls (below 80 mg/ 100 ml) in the blood. This is influenced by the glucagon hormone.
• Glucogenesis. Synthesis of glucose from other carbohydrates.
• Gluconeogenesis. Synthesis of glucose/carbohydrates from protein and lipids (non-carbohydrate sources)
• Lipogenesis. Extra protein and carbohydrates are converted into lipids for storage in adipose connective tissue.
• Deamination of protein. If protein is used for energy production, the NH₂ group is removed from amino acid as NH₂, the end product of keto acid, enters the Krebs cycle.
• Ornithine Cycle. The chemical part of excretion, NH₃ is converted into urea in a cyclic chain of reactions in which ornithine plays a pivotal role.
• Cori Cycle. Lactic acid formed in muscle is convened buck In glycogen. Synthesis of substances like.
• VitA from carotene.
• Vit-D front cholesterol or ergocalciferol.
• Plasma protein (Albumin, globulin. clotting proteins). heparin.
• Angiotensinogen is an osmoregulatory substance in the blood.
• Haemoglobin, formation of UHC in frog and embryonic mammals.

Human Digestive System NEET Biology

Somatomedin, a growth-promoting factor also called IGF (insulin-like growth I actor) Detoxification of the following substances take place in the liver

• Indole, skulls. cresol. phenol, alcohol, prussic acid and other toxic substances formed during digestion or obtained in blood.
• Excess alcoholism affects the liver by overburdening work and fat deposition.
• It converts alcohol to aldehyde which promotes lat deposition and causes puffiness and liver cirrhosis.
• Storage of the following substances takes place in the liver
• Glycogen, Vitamins like VitA, VitD, Vitk, VitB₁₂  folic acid etc. Fe and Cu.
• Water, lymph and blood, (about 1/5th of total blood).
• By storing blood and water, the liver controls the volume and viscosity (concentration) of blood.
• By generating and consuming heat in a different chemical reaction it acts as a thermoregulatory organ.

Secretion of Bile

• Bile is a yellowish watery fluid, concentrated in the gall bladder, contains 85% water; 6% organic salt of bile acids (sodium glycocholate and sodium taurocholate); 1% inorganic salt (bicarbonate, carbonates and chlorides of Na and K); 1.5 to 2% lipid (cholesterol, lecithin); 3% mucin and bile pigment (bilirubin and biliverdin).
• Extra cholesterol and bilirubin are eliminated from the body through the gut.
• An increase in bilirubin level beyond normal (0.1 to 0.9 mg/100 ml.) in the blood is called jaundice. This happens if hepatic cells become sick due to viral or bacterial infection obstruction or lesion,

Gastric glands

• Gastric glands are microscopic and present in the walls of the stomach. These glands secrete gastric juice,
• A gastric, gland. has three types of cells.
• Mucous cells,- Secreting mucus
• Chief or peptic cell – Secreting pepsinogen zymogen cells and prorenin

Oxyntic. cells or parietal cells – Secreting HCL

Pancreas

The pancreas is the second largest gland in the human body. It is yellow-coloured, 12-15 cm long and a compound racemose gland. It is present in the loop of the duodenum. It is formed of head, body and tail.

• Pancreas is a heterocrine gland. Its exocrine part is formed of a large number of lobules or acini. Each acinus consists of several glandular cells which secrete the pancreatic juices (pH 8.8). Pancreatic juices are drained by a pancreatic duct which joins the bile duct as described in the liver. About 1500 ml of pancreatic juice is secreted per day.
• The rest part remains filled with areolar connective tissue known as stroma.

1. Pancreatic secretion water-99%
2. Inorganic – 0.5% (High amount of NaHCO₃)
3. Organic – 0.5% Mostly enzymes

Intestinal glands

1. They are present in the wall of the intestine. These glands secrete intestinal juice (succus entericus)
2. The wall of the duodenum contains intestinal glands (crypts of Lieberkuhn) and characteristic duodenal glands or Brunner’s glands produce alkaline mucus.
3. In between the villi, the mucous membrane of the small intestine is folded forming intestinal glands or crypts of Lieberkuhn.
4. The intestinal juice or succus entericus is secreted by the crypts of Lieberkuhn.
5. Intestinal villi are more numerous and larger in the posterior part of the small intestine than in the anterior part because there is more digested food in the posterior part.

NEET Biology Animal Nutrition And Digestive System Important Points

NEET Biology Animal Nutrition and Digestive System Histology Of Wall Of Gut

• Histology of wall of gut from outer to inner side.
• Serosa – Peritoneum and Connective tissue Muscular Layer – Outer Longitudinal and inner Circular (Stomach – oblique muscles additional layers)
• Sulunueosa – Connective tissue Mucosa

1. Muscularis mucosa
2. Lamina propria (reticular connective tissue)
3. Surface epithelium.
4. Mouth and Pharynx

• Lined with the stratified squamous epithelium of ectodermal origin, hence representing the stomodaeal part. Possesses a striated muscle layer, hence the movement of food here is voluntary.

Oesophagus

1. All four layers are typical as it serves only as the passage.
2. Its thoracic part is without a serosa layer which shifts to form the mediastinal wall

Stomach

1. Thick and highly distensible wall, when empty it forms inner longitudinal folds, rugae.
2. The muscular layer is the thickest of all parts with the third and innermost oblique muscle layer.
3. Submucosa has no speciality.
4. Mucosa forms glands by invaginating into the submucosa and has three types of cells :
5. Mucous (Goblet) cells secrete mucin
6. Oxyntic (Parietal) cells secrete HCL
7. Chief cells (Peptic or zymogenic) cells secrete enzymes.
8. Cells of mucosa are secretory but not absorptive.

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Small Intestine

The muscle layer is typical (no speciality).

1. Submucosa is the most developed and specialised of all parts with the following structures :
2. A highly organised system of blood capillaries up to villi for the transportation of absorbed food.
3. Fine lymphatic channels (lacteals) are extended up to villi for absorption and transportation of lipids.
4. The muscle layer (muscular mucosa) is present just behind the mucosa for the movement of villi.
5. Two nerve plexuses of the autonomic nervous system (ANS) are present.
6. The lymph nodes and Peyer’s patches are present which act as biological filters.
7. Submucosa and mucosa together form inner transverse finger-like folds to increase the surface area of absorption. In mammals, the primary folds are called folds of Kerkering (or valvulae connivance or plica circular), which bear true villi as secondary folds.
8. Folds of Kerkering increase surface area of absorption by 3 times, villi increase by 10 times and microvilli of mucosal cells increase by 20 times, thus total increase is by 600 times which comes to about 250 mtr2 in man.

• Mucosa is the main functional layer for digestion and absorption with brush border cells both secretory and absorptive. Mucosa forms glands embedded in submucosa are:
• Brunner’s gland (duodenal gland). Present mainly in the duodenum; secretes mucus; absent in the frog.

1. Crypts of Lieberkuhn. Small flask-shaped gland in the crypts between two villi.
2. Cells of Paneth in it secrete digestive enzymes, called succus entericus

Large Intestine: Thin-walled and transparent, divided as caecum, colon, and rectum.

Colon

1. No secretion, no glands at all.
2. There are three inner longitudinal folds called taeniae – specialized structures for the absorption of water.
3. The transverse membranous foils between two taeniae form a series of pockets, dentistry, highly developed in desert or dryland animals like rabbit, pont. camel etc. but, less developed in man

NEET Biology Animal Nutrition And Digestive System Important Points

NEET Biology Animal Nutrition and Digestive System Rectum

1. Has six or more folds called rectal papillae for the absorption of water,
2. Goblet cells secrete mucus to facilitate defecation.
3. Physiology of Digestion
4. Digestion is the process of conversion of complex food into simple (absorbable) form, lists involve two parts :
5. Mechanical part. Cutting and chewing of food to increase its surface area for enzymatic action,
6. Chemical part. Enzymatic hydrolysis of food i.e. breaking tit molecular level i.e. actual digestion.
7. It could be both extracellular and intracellular, but secures, optimal efficiency of extracellular digestion.
8. Discovered by Beaumont (1833).
9. It begins from the mouth and continues up to the small intestine, in herbivores digestion also takes place in the caecum but with the help of bacterial enzymes.

NEET Biology Animal Nutrition and Digestive System Absorption Of Food

Talcs place, mainly jejunum and ileum through villi and microvilli by both active and passive preveses. It first enters mucosal cells and then passes into the submucosa.

1. No absorption occurs in the stomach except that of ethanol (alcohol) and aspirin.
2. Water is absorbed in the small intestine and large intestine.

Absorbed food is transported through two pathways: the hepatic portal system, directly to the liver and through the lymphatic channel it is drained into subclavian veins via the thoracic duct.

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Absorption of Glucose and Amino acids

1. Both are absorbed mainly by active transport as this process is many thousand times faster than passive transport.
2. Entry of glucose in the cell is coupled with Na⁺  where it immediately gets phosphorylated.
3. Galactose is absorbed like glucose, and some disaccharides are absorbed directly.
4. Fructose and mannose are absorbed by facilitated diffusion.
5. From submucosa, these pass out through blood capillaries.

Absorption of Lipid: Glycerol and fatty acids in the cell generally combine to form lipids again. Thus lipid is absorbed in both forms :

Directly as lipid

• Lipid enters mucosal cells as chylomicrons and micelles by pinocytosis in the crypts between villi.
• Chylomicrons are lipid droplets of < I pm diameter formed by emulsification. With non-lipid substances like salts, amino acids etc. it forms micelles.
• In submucosa, it enters lacteals and moves with lymph.
• As glycerol and fatty acid
• Glycerol is soluble in both the aqueous and lipid phases and hence easily passes through the cell membrane.
• Small soluble fatty acids enter the cell as the membrane component, while large insoluble fatty acid after combining with (bile) forms a soluble micelle.

Animal Nutrition And Digestive System NEET Chapter Summary

NEET Biology Animal Nutrition and Digestive System Egestion (Efaecation or Defecation)

• It is a tile process of elimination of faeces.
• Slercobilin causes the brown/yellowish colour of faeces.
• The foul odour of faeces is due to indole and skatole funned by decarboxylation of amino acids by bacteria in the colon.

NEET Biology Animal Nutrition and Digestive System Components Of Foods

The food of animals is chiefly formed of six kinds of components

1. Carbohydrates
2. Proteins
3. lipids
4. vitamins
5. Water
6. Minerals.

Out of these food components, carbohydrates, proteins, and fats are called macronutrients or proximate principles of food, while vitamins and minerals are called micronutrients or protective principles of food.

Proteins

• Proteins are major building blocks as 75% of our body consists of proteins. All enzymes, O. earning pigments, antibodies, most hormones, arc proteins.
• The chief source of proteins is milk. egg. fish. meat, pulse and cereals. Its requirement is more for growing children and pregnant and lactating mothers.
• Proteins are more important for anabolism than catabolism Calorific value of proteins is 5.65 K cal and 20 amino acids, linked together by peptide bonds, make all different proteins.

Eight are considered essential (which cannot be synthesized in the body and lias to be taken in diet), and 12 are non-essential (which can be synthesized in the body) which 2 are considered semi-indispensable because they may be synthesized in tissues but not at adequate rates to support growth in younger human individuals.

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NEET Biology Animal Nutrition and Digestive System Carbohydrates

1. Chemical composition. Carbohydrates are polyhydroxyaldehydic or ketonic organic compounds. These are usually formed of C, H and O in the ratio of 1:2:1 with only a few exceptions.
2. These are called carbohydrates because there is generally one water molecule for every carbon atom. The general formula is :
3. Cn(H₂:0)_n where n is several carbon atoms, so arc called “hydrates of carbon” The Name of carbohydrates ends with the suffix – ose.
4. Sources. Main sources of carbohydrates are potatoes (20%), fruits (banana – 20%, mango), cereals (rice – 23%. wheat – 57.3%), sugar, honey, sugarcane, sugarbeet, jam,’ bread, milk 4%) etc.

Daily requirements. On average, the need for carbohydrates for an adult person is 100 g per day. About 55-75% of total good calories should be in the form of carbohydrates.

1. Of these. 80-85% should consist of easily digestible starch and dextrins. Requirements are more for mountaineers, athletes, labourers etc.
2. Carbohydrates form about 1% of our body weight.

Functions. As Respiratory fuels. Carbohydrates, especially glucose, are the main respiratory fuels. About 60% of our total energy needs are provided by the breakdown of carbohydrates is 4.1 kcal of energy while the physiological fuel value of one gram of carbohydrates is 4.0 kcal (17 kJ) of energy.

• To provide energy, the glucose undergoes biological oxidation in the mitochondria (powerhouse) of the cell to produce about 36 or 38 molecules of ATP.
• So die theoretical recovery- of energy from one glucose molecule of 40%. The main reasons for the glucose being chief respiratory fuel are its presence in abundance and its easy oxidisability.
• C₆H₁₂O₆+6O₂ > 6CO₂ + 6H₂O + Energy
• So carbohydrates form the cheapest sources of energy.
• Monosaccharides as structural components

Ribose (Pentose sugar) is a component of RNA; conenzymes like NAD, FAD etc. and energy carriers like ATP, GTP etc.

• 2′-Deoxyribose (Pentose) is a component of DNA.
• Galactose is a structural component of the medullary sheath.
• As building blocks. Monosugars act as monomers for the formation of disaccha¬rides and polysaccharides.
• Reserve foods. There are two main polysaccharides which act as reserve foods e.g. starch is a storage polysaccharide of plants and is stored as granules in amyloplasts.
• Glycogen is the reserve food stored in the liver and muscles in animals.
• The energy requirement of the body Organisms requires energy continuously. When work is done, energy is being spent. This energy is required to keep all systems in the body functioning.

• A normal healthy man requires about 3000-kilo calories per day. Perhaps a sedentary worker needs a little less, say 2500 kilo calories hardworking labourer may need about 3500-kilo calories per day.
• (Note: The term Calorie (capital C) as used by nutritionists is equivalent to 1 kilo calorie (kcal)) The energy requirement is calculated as so many calories for an hour for a particular type of work.

1. Basil metabolism. The amount of energy required by the body to maintain vital functions when no muscular work is being done and no food is being digested.
2. Rasul metabolic rate (BMR). The amount of energy required daily by a person to maintain their basal metabolism is about 1,600 keal/day.
3. Active metabolic rate (AMR). The amount of energy required daily by a person to maintain their high metabolic rate during heavy physical work is about 6,000 kcal/ day.
4. Roughage. The indigestible fibrous material of food is called roughage For Example. cellulose of cell walls of plant material promotes peristalsis and checks constipation.
5. Balanced diet. A diet which can provide materials for all the metabolic requirements of the body. Carbohydrates, proteins and fats should be nearly in the proportion of 4: 1: 1.

Lipids. Lipids comprise heterogenous organic compounds which are insoluble in water but are readily soluble in non-polar organic solvents like ether, chloroform, benzene etc. On hydrolysis.

• lipids yield fatty acids which are utilized by living organisms. In addition to fats, lipids include waxes, phospholipids, glycolipids and fat-soluble vitamins A, D, E and K).

Daily Requirement. About 50 gms. of fat are needed by man daily. Fats are digested slowly and delay the hunger sensation between meals. Our diet should contain less saturated fats, such as butter, ghee and hydrogenated vegetable oils, than unsaturated fats, such as simple vegetable oils.

• Excess of saturated fats increases the cholesterol and causes arteriosclerosis.

Sources. The sources of fats in our diet are vegetable cooking oil, vanaspati ghee, desi ghee, butter, cream, oil seeds and nuts, milk, cheese, mutton and eggs.

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Uses. The fats also serve a variety of functions:

1. fuel,
2. reserve food
3. insulator
4. formation of cell organelles
5. shock absorption.

Animal Nutrition And Digestive System NEET Chapter Summary

NEET Biology Animal Nutrition And Digestive System Vitamins

N.I. Lunin was the first to identify vitamins, and Funk was the first to use the term “vitamins.” The “vitamin theory” was introduced by Hopkin and Funk in 1912, which posits that deficiencies in vitamins are the cause of deficiency diseases.

• As growth and metabolic regulatory substances, vitamins are intricate organic compounds that are required daily in minute quantities.
• Green plants are the sole source of vitamin synthesis; consequently, animals are reliant on plants to meet their vitamin needs.
• The human body can store A, D, and ll,2 and produces vitamin D through the use of ultraviolet radiation of sunlight. Vitamins are named after the alphabets they represent, their chemical composition, and the deficiency diseases they prevent.
• Vitamins are compromised by excessive heating, frying, and low temperatures. It is feasible to synthesize vitamins, as their chemical composition is recognized. Vitamins are classified as either fat-soluble (A, D, E, and K) or water-soluble (B and C).

Animal Nutrition And Digestive System NEET Chapter Summary

NEET Biology Animal Nutrition and Digestive System Memory Points

• PFA Polyunsaturated fatty acids are found in abundance in corn oil and sunflower oil
• NiN National Institute of Nutrition
• Vit C was the first vitamin to be produced during the fermentation process using wild bacteria.
• Vit B₁₂ was first to be isolated in 1948 from liver extract and during the production of antibiotics in fermentation.
• Within the body, vitamin B₁₂ is produced by the microflora of the digestive system.

Excessive intake of vitamin A causes bone reabsorption and hypercalcaemia.

1. An alcoholic is always deficient in Vit. C
2. Vitamin B₁₇ is a recently discovered vitamin with anti-cancer properties.
3. Vitamin theory was proposed by Hopkins and Funk.
4. Earlier known vitamin -Vitamin C
5. Vitamin B₆ is used in the treatment of tuberculosis

• Vit P Hesperdin is insoluble in water and is present in citrus fruits and green vegetables. It maintains blood capillary resistance. Its deficiency causes subcutaneous bleeding. ,
• Vitamins which are synthesized by the intestinal flora are vitamin K, Thiamine, Riboflavin, Pantothenic Acid, Niacin, Pyridoxine, Biotin and Folic acid.
• Vitamin B₁₂ and alcohol. Alcohol interferes with the metabolism of B₁ in the liver. Alcohol intake along with a deficiency of vitamin B₁ can also cause brain cell damage. Therefore, regular alcohol drinkers should take vitamin B complex every day.
• Cod Liver oil is considered to be a rich source of vitamins A and D.
• Presently Vit B₁₂ is produced directly during the courses of fermentation by propioni bacteria and certain strains of Pseudomonas.
• Vit B₁₂ is found essentially in cereals, vegetables and brewer’s yeast. It was produced in 1938 by using microbes.
• Most of the B complex vitamins are coenzymes.
• Wheat grain contains – Vitamins such as thiamine, riboflavin, niacin, pantothenic acid, folic acid, and tocopherol (The richest source)
• Proteins & Minerals P, K, Mg, Mn, Ca, Na, Sn, Zn. & Fat.
• Destruction of vitamins. Overcooking, excessive alcohol, tobacco and coffee; certain medicines destroy vitamins
• Dietary deficiency of proteins leads to a fall in plasma proteins which are important for the retention of water in blood plasma by their osmotic effect.
• A fall in plasma proteins leads to filtering out excessive volumes of water from the blood to the tissues. Excessive accumulation of fluids in the body tissues causes oedema.
• Zinc is necessary to maintain normal plasma concentration of vitamin A.

Animal Nutrition And Digestive System NEET Chapter Summary

NEET Biology Animal Nutrition And Digestive System Physiological Role And Source Of The Important Minerals

NEET Biology Animal Nutrition and Digestive System Disorders Of the Digestive System

• Nausea- discomfort preceding vomiting.
• Anorexia – loss of appetite.
• In India, Orissa tops the list of states of people suffering from malnutrition.
• Enlargement of rectal vein which causes piles.

Dyspepsia. Indigestion due to defective diet.

• Pavlov pouch was fabricated by Pavlov to study the effect of feeding on gastric secretion.
• Peristaltic movements are low in the rectum.
• A hiatal hernia or diaphragm is the opening in the diaphragm. The part of the stomach is pushed into the thoracic cavity.
• Gastritis is inflammation of the gastric mucosa.
• A peptic ulcer is an erosion of the stomach or duodenal mucosa.

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Cirrhosis of the liver – The liver appears orange. It is due to the accumulation of bilirubin in the liver. Other substances are mixed with the yellow pigment (bilirubin), hence the liver appears orange.

• Hepatitis is inflammation of the liver.
• Pancreatitis is inflammation of the pancreas.
• Constipation is the infrequent passage of dry, hardened faeces.
• In ulcerative colitis the mucosal lining of the colon becomes ulcerated.
• Some people cannot digest milk and milk consumption in them causes diarrhoea and gas generation because they do not produce lactase. The lactose of the milk is fermented by intestinal microflora-producing gas.
• Removal of the stomach produces dumping syndrome.
• Treatment with all axons destroys 3 cells of pancreatic islets
• Treatment with CaC₁₂ destroys cells of islets of Langerhans
• Abnormal metabolism of fats causes Gaucher’s disease (also called cerebroside lipidosis)
• PEM Protein Energy Malnutrition
• Kwashiorkor Marasmus
• FFA Free fatty acid,
• Avg. Indians Iwvo to obtain about 50% of their requirements of energy from early dratos, 33% from fats and 15% from protein.
• The vermiform appendix (1.. vermiformis, worm-like; appendix, attachment) is a short, thin outpouching of the caecum. It does not function in digestion, but like the tonsils, it contains numerous lymphatic nodules and is subjected to inflammation a condition called appendicitis.
• It is commonly detected in its later stages be pain. Rupture of the appendix can cause inflammation of the surrounding body cavity peritonitis.

1. The substances which provide materials for growth, energy and maintenance are called nutrients.
2. The process of procurement of nutrients is called nutrition.
3. The mode of nutrition may be autotrophic or heterotrophic.
4. Nutrients may be organic or inorganic.
5. Proximate principles of food
6. They are macronutrients
7. These include carbohydrates, lipids and proteins.
8. They are energy sources and help in carrying out organic functions.
9. Protective principles of food
10. They are micronutrients.
11. These include water and minerals.

• They do not provide energy but help in carrying out various vital processes.
• About 20 vitamins are required in small amounts.
• The mode of nutrition in animals is heterotrophic which may be holozoic or saprozoic.
• Based on food habits holozoic animals are classified into herbivores, carnivores, omnivores, insectivores, sanguivores, detritivores, insectivores or fluid feeders.
• Ingestion is the intake of food.
• Microphagous animals. These animals feed on those solid particles which are too small to be captured singly. These animals possess different types of filtering devices. Therefore, the method of intake is also known as filter feeding.

1. The water passes through the filters and food is retained (e,g., pseudopodia, cilia, flagella and setae in some crustaceans etc.)
2. Filter feeders. They are aquatic animals and feed on tiny particles suspended in water.
3. Examples. Lepas (Crustacean), Molluscs, Amphioxus. Herdmania.
4. Macrophagous animals. These animals feed on those solid particles which are large enough to be captured singly. Filters are absent in these animals. The method of capturing food is different in different animals.
5. Pseudopodia capture and ingest the food in amoeba. This process is called phagocytosis. Earthworms spreads its mouth cavity to capture the food. Coelenterates capture the food with the help of tentacles.
6. Fish, amphibians, creeping animals and birds capture their food with the help of jaws, tongues and beaks and ingest it without chewing them. The food captured by most of the mammals is masticated before being swallowed.
7. Their teeth as well as jaw bones and muscles are specially developed for mastica¬tion. In herbivores, the premolars and molars have predominant ridges on the crowns for effective grinding. The carnivores, however, have large and sharp canines for tearing the flesh of prey.

Mutualism. Two organisms living in association with each other derive nutrition from each other, in such case nutrition is called mutualism.

Examples of mutualism

• E.coli living in the intestine of man synthesises vita-min B₁₂, which is utilised by man and E.coli receives, in return simpler food from the intestine of man.
• Rhizobium bacteria live in the nodules of leguminous plants.
• The cloacal thymus is the purely endocrine gland on the roof of the cloaca of the birds discovered by Fabricius.
• Mass peristalsis is initiated in the colon about half an hour after taking food.
• Riboflavin was called ‘yellow enzyme’ by Warburg and Christian.

Animal Nutrition And Digestive System NEET Chapter Summary

NEET Biology Animal Nutrition And Digestive System Quanta To Memory

Oesophagus. In Birds, the oesophagus is very long and often dilated in front of the sternum into a large, thin-walled crop to store food before digestion. Crop glands in both sexes secrete a nutritive fluid the pigeon’s milk, which is regurgitated and fed to the hatchlings.

1. In the upper one-third of the oesophagus, only skeletal muscles are found.
2. After the voluntary phase, swallowing of ‘bolus’ becomes an involuntary reflex triggered by tactile stimulation of the palate and pharyngeal wall controlled by the swallowing centre in the medulla and lower parts of the brain stem.
3. In humans, more than one litre of saliva is secreted into the oral cavity.
4. spite of the fact the mucus protects the stomach lining from being digested, it is completely replaced every 3 days.
5. Each day, the stomach wall secretes about 3 litres of gastric juice.
6. About every 20 seconds, the stomach contents are mixed by the churning action of smooth muscles. When an empty stomach churns, hunger pangs are felt.
7. It takes about 2-6 hours after a meal for the stomach to empty.
8. Amylases found in animals are called a-amylose, and those in plants are called /Lamylose.
   • Stomach. Cyclostomes and the carp, Labeo, lack stomach.
   • Water Cells. These are sac-like diverticula arising from the rumen and reticulum of the camel stomach. They contain food undergoing digestion and do not store water as commonly supposed.
   • Camel can go without taking water for a long time as it can use metabolic water formed by chemical breakdown of stored glycogen and fat.
   • Intrinsic Castle’s Factor. It is secreted by parietal cells of the gastric glands and aids in vitamin B]2 absorption. Lack of this vitamin makes the bone marrow unable to form sufficient red corpuscles, causing pernicious anaemia.
   • Small Intestine. Final digestion of double sugars right on the surface of microvilli and of dipeptides on the microvilli and within the microvilli-bearing cells. Products of digestion, viz., glucose and amino acids, are released into the intestinal lumen.
   • Paneth Cells. These occur at the base of the crypts of Lieberkuhn and secrete antibacterial lysozyme.
   • Argentaffin Cells. These also occur at the base of the crypts of Lieberkuhn. They secrete some gastrointestinal hormones and neurotransmitters.
   • Peyer’s Patches. These are white patches on the intestinal mucosa. They consist of lymphoid tissue packets with white corpuscles. They fight infection and are often called abdominal tonsils.

Nutrient Absorption In Small Intestine NEET Exam Preparation

Large intestine. The vermiform appendix contains lymphoid tissue that neutralizes bacterial toxins.

1. Some of the bacteria including Escherichia coli present in the large intestine or colon produce vitamin K, which is absorbed by the host and this is probably the main source of this vitamin for humans.
2. Millions of cells lining the human stomach and intestine are abraded away and destroyed every time the food is digested, but cell division constantly regenerates the lining of the digestive tract.

• Every five days, the lining of the human small intestine is entirely replaced as a result of ongoing cell division.
• Parietal cells of the stomach give MCI and chief cells give pepsinogen.
• The surface of the upper gastrointestinal tract, oesophagus, and mouth have a much thinner, mucous cell layer than the stomach, which is why vomiting can cause, a burning sensation in the oesophagus or mouth.
• The vermiform appendix (L. vermiform’s, worn-like; appendix, attachment) is a short, thin outpouching of the caecum. It does not function in digestion, but like the tonsils, it contains numerous lymphatic nodules and is subject to inflammation a condition called appendicitis.
• It is commonly detected in its, later stages by pain. Rupture of the appendix can cause inflammation of the surrounding body cavity peritonitis.
• About 40-50 lakh villi are present in the human intestine.
  1. On the surface of each epithelial cell of villi about 650 microvilli are present, ‘
  2. The functional and structural unit of the liver is the liver lobule Part of the alimentary canal where NH₃ (Ammonia) is produced during digestion is the caecum
  3. Bursa Fabrici. It is a blind sac on the cloaca in birds. It has lymphoid tissue involved in antibody production and in fighting invading bacteria. It is, therefore called cloacal thymus.
  4. Like the thymus, it is prominent in early life and tends to atrophy in the adult.
  5. The centre in the brain which controls hunger is known as the satiety centre. It is located in the hypothalamus of the brain.
  6. The chief function of the ileum is absorption.
  7. The most important functions of saliva are mechanical.
• Piscivorous animals feed on fish. ,
• Saliva and tears contain an antibacterial enzyme called lysozymes.
• Poison glands of snakes are modified labial glands homologous to parotid salivary glands.
• The liver of a rabbit is encapsulated by two sheaths – an outer membranous serous capsule consisting of a visceral peritoneum and an inner Glisson’s capsule of a thin layer of dense connective tissue. Glisson’s capsule is found in the liver of some mammals.
• The rumen, Reticulum, Omasum and Abomasum are the correct sequence through which food passes through a ruminant.
• Diastema is a toothless space in rabbits between the incisors and premolars.
• Fibres running between the periodontal membrane to the root of the tooth across the cement are known as Sharpey’s fibres.
• C-shaped duodenum is a characteristic of man. Reverse peristalsis or anti-peristalsis in the stomach and duodenum causes vomiting.
• The vomiting centre is the medulla oblongata of the brain.
• Some people suffer from “travelling sickness” on their way to a hill station in a bus, the sickness comprises nausea and vomiting, which are due to rapidly changing directions of motion of the body stimulating the receptors of the membranous labyrinth, from where the stimuli reach the vomiting centres in the medulla oblongata through the cerebellum.
• Peristaltic movements are the least in the rectum of the alimentary canal.
• In herbivorous animals, the small intestine is much longer (tadpole) than that of carnivorous animals (For Example. frog in proportion to body size)
• In rabbits, there are 4 pairs of salivary glands: Parotid, sub-axillary, sub-lingual and infraorbital (below the orbits and absent in man).
• Liver. It is relatively much larger in the foetus. It has a double blood supply: about 70% coming from the hepatic portal system and 30% from the arterial system.
• The liver of a rabbit is formed of five lobes: Right central (largest), left central, left lateral, caudate and Spigelian (smallest and absent in the liver of man).
• Faecal matter is solid in the descending colon.
• The lining cells of the small intestine have microvilli for absorbing digested food. The microvilli are not present in the embryo but develop after birth as the young one starts suckling.
• Once glycogen reserve is exhausted the adipose tissue (fat cells) comes to the rescue of the fasting person.
• Bp is absent in plants, but present in almost all animal tissues of which rich sources are liver, kidney, milk, etc.
• Tapeworms are said to be “Wallowers” because they absorb nourishment through their body surface.
• Rennin is secreted by young mammals. It is not secreted by adult mammals.
• The first pancreatic transplant took place in l%6 in the U.S.
• Bad breath is usually due to cavities in the teeth, and infection of the throat and nose.
• Many people are overfed but undernourished.

1. Tea/coffee inhibits the absorption of iron from the diet. Prolonged consumption of tea or coffee after meals can lead to iron deficiency anaemia.
2. The cells of the epithelial lining in a vertebrate stomach are not damaged by HC₁ because of mucus secretion covering the epithelium.
3. Under extreme demand of glucose (starving) even reserve proteins and fats are converted into glucose through a process of gluconeogenesis.
4. Wound healing is enhanced by Vit-C.
5. Lips (Labia Ora). Chelonians and birds lack lips. The upper lip of rabbits, hares, rats and squirrels has a median vertical cleft, the harelip, exposing the upper teeth. Some humans also have harelip as a congenital abnormality.
6. It can be set right by a surgical operation. The upper lip and snout are prolonged into a long, thick, prehensile proboscis or trunk in elephants. Platypus and whales lack movable lips.
7. Cheek Pouches. In some rodents (squirrel, rat) and certain old-world monkeys, the vestibule (space between cheeks and jaws) extends to form cheek pouches for temporary storage of masticated food.

Animal Nutrition And Digestive System NEET Chapter Summary

NEET Biology Questions For Competitive Examinations

Question 1. Protein/enzyme is absent in :

1. Saliva
2. Bile
3. Pancreatic juice
4. Intestinal juice.

Answer: 2. Bile

Question 2. Match the degestive juices listed under Column-1 with the enzymes given under Column-2; Choose the choice which gives the correct combination of the alphabets of the two columns.

1. A — r, B — s, C — p, D — t
2. A — r, B — t, C — p, D — q
3. A — s, B — r, C — p, D — t
4. A — r, B — S, C — q, D — p.

Answer: 4. A — r, B — S, C — q, D — p.

Question 3. What should be taken to offset the deficiency of rhodopsin?

1. Papaya and Mango
2. Orange and Amla
3. Watermelon and Strawberry
4. All the above.

Answer: 1. Papaya and Mango

Question 4. Vitamins required for the development of erythrocytes are:

1. D
2. B₁₂
3. E
4. K.

Answer: 2. B₁₂

Disorders Of Digestive System NEET Biology

Question 5. In the case of taking food rich in lime juice, the action of ptyalin on starch is :

1. Enhanced
2. Reduced
3. Unaffected
4. Stopped.

Answer: 2. Reduced

Question 6. Digestive juice contains catalytic agents called :

1. Vitamins
2. Hormones
3. Enzymes
4. Nitrates.

Answer: 3. Enzymes

Question 7. Bile acids are :

1. Steroids
2. Carbohydrates
3. Modified proteins
4. Vitamins.

Answer: 1. Steroids

Question 8.Which one correctly matched :

1. Vit. E-Tocoferol
2. Vit. D-Riboflavin
3. Vit. B-Calciferol
4. Vit. A-Thiamine

Answer: 1. Vit. E-Tocoferol

Question 9. Where does the conversion of harmful prussic acid into potassium sulphocyanide take place?

1. spleen
2. liver
3. bone marrow
4. lymph glands.

Answer: 2. liver

Question 10. Water is absorbed mainly by :

1. Large intestine
2. small intestine
3. stomach
4. pancreas.

Answer: 1. Large intestine

Question 11. The number of different teeth (incisors, canines, pre¬molars and molars) in each jaw are :

1. 4, 4, 6. 4
2. 4,2,4,6
3. 4, 2, 5, 6
4. 6, 2, 4, 4.

Answer: 2. 4,2,4,6

Question 12. “Your food shall be your medicine”. This quotation was given by :

1. Newton
2. Hippocrates
3. Einstein
4. Lenz.

Answer: 2. Hippocrates

Question 13. Term proteins were first used by :

1. Berzelius
2. Funk
3. Kuhne
4. Marconi.

Answer: 1. Marconi

Question 14. Gall baldder is absent in :

1. cow
2. pig
3. horse
4. cat.

Answer: 3. horse

Disorders Of Digestive System NEET Biology

Question 15. Vitamin K is necessary for:

1. R.B.C.
2. W.B.C.
3. plasma
4. production of prothrombin.

Answer: 4. production of prothrombin

Question 16. A person suffering from profuse bleeding after an injury. Such a person is deficient in which vitamin?

1. Vit A
2. Vit K
3. Vit D
4. Vit E.

Answer: 2. Vit K

Question 17. Which of the following is the largest part of a cow’s alimentary canal?

1. Reticulum
2. Rumen
3. Omasum
4. Abomasum.

Answer: 2. Rumen

Question 18. Absorption of glucose and amino acids occurs by:

1. Passive absorption
2. Active absorption
3. Simple diffusion
4. Facilitated diffusion.

Answer: 2. active absorption

Question 19. Magnesium is most abundant in :

1. milk
2. meat
3. soybean
4. fish.

Answer: 2. meat

Question 20. Deficiency of which of these causes anaemia?

1. Fe
2. Zn
3. A1
4. Mg.

Answer: 1. Fe

Question 21. Which one pair is not correctly matched?

1. Vit Bp-Pernicious anaemia
2. Vit B6-Beri-Beri
3. Vit C-Scurvy
4. Vit B₂ -Pellagra.

Answer: 4. Vit B₂ -Pellagra

Question 22. Lysozymes are found in :

1. Mitochondria
2. Tears
3. Saliva and tears both
4. Saliva.

Answer: 3. Saliva and tears both

Question 23. Just as hydrochloric acid is to pepsinogen so is :

1. Enterokinase to trypsinogen
2. Haemoglobin to oxygen
3. Bile juice to fat
4. Glucagon to glycogen.

Answer: 1. Enterokinase to trypsinogen

Disorders Of Digestive System NEET Biology

Question 24. Plasma protein also performs :

1. Nutritive function
2. Physioehemienl function
3. Transportive function
4. All the above three.

Answer: 4. All the above three

Question 25. Which is non-reducing sugar?

1. glucose
2. galactose
3. mannose
4. sucrose.

Answer: 4. sucrose

Question 26. Which is false for nutrition in Amoeba?

1. pseudopodia feeder
2. holozoic nutrition
3. photonivorous
4. Photoautotroph.

Answer: 4. photoautotroph

Question 27. Match the types of cells listed under column 1 with the secretions under column II. Choose the answer which gives the correct combination of the alphabet of two columns :

1. A = s b = r ; C = p D = t
2. A = q b = r; C = p D = t
3. A – s b = q; C = p D = t
4. A = t b = q; C = r, D = S.

Answer: 1. A = s b = r ; C = p D = t

Question 28. The lacteals are found in :

1. Spleen
2. Mammary gland
3. Salivary gland
4. Villi.

Answer: 4. Villi

Question 29. Number of teeth which grow twice are :

1. 8
2. 14
3. 12
4. 20.

Answer: 4. 20

Animal Nutrition And Digestive System NEET Notes

Question 30. Which of the following is not an insectivorous plant?

1. Drosera
2. Nepenthes
3. Monotropa
4. Utricularia.

Answer: 3. Monotropa

Question 31. Seaweeds are important sources of :

1. Chlorine
2. Fluorine
3. Iodine
4. Bromine.

Answer: 3. Iodine

Question 32. During digestion, lymphatics of the intestine become filled with fat globules giving a white colour to the lymph. This lymph is called :

1. Cistron
2. Chyle
3. Chyme
4. Bilirubin.

Answer: 2. Chyle

Question 33. Cattle fed with spoilt hay of sweet clover which contains dicumarol :

1. Are healthier due to a good diet
2. Catch infections easily
3. May suffer from vitamin K deficiency and prolonged bleeding
4. May suffer from Beri Beri due to a deficiency of B vitamins.

Answer: 3. May suffer from vitamin K deficiency and prolonged bleeding

Question 34. Duodenum has characteristic Brunner’s glands which secrete two hormones called :

1. Prolactin, Parathormone
2. Estradiol, Progesterone
3. Kinase, Estrogens
4. Secretin, cholecystokinin.

Answer: 4. Secretin, cholecystokinin

Question 35. The richest sources of vitamin B,2 are :

1. Chocolate and green grain
2. Rice and Men’s egg
3. Carrol and chicken’s breast
4. Goat’s liver and Spirulliiui

Answer: 4. Goat’s liver and Spirulliiui

Question 36. Which one of the following pairs is not correctly matched?

1. Vitamin B₁ = Beri-Beri
2. Vitamin B₂ = Pellagra
3. Vitamin B₁₂ = Pernicious anaemia
4. Vitamin B₆ = Loss of appetite.

Answer: 2. Vitamin B₂ = Pellagra

Question 37. Which one of the following is the correct matching of a vitamin, its nature and its deficiency disease?

1. Vitamin A – Fat-soluble – Beri-Beri
2. Vitamin K – water-soluble – Pellagra
3. Vitamin A – Fat soluble-Night blindness
4. Vitamin K – fat soluble – Beri-Beri.

Answer: 3. Vitamin A – Fat soluble-Night blindness

Animal Nutrition And Digestive System NEET Notes

Question 38. Which of the following is a mismatch? :

1. Thiamine – Damage to nerves and heart
2. Ascorbic acid – Scurvy
3. Riboflavin – Slow rate of clotting of blood
4. Niacin – Damage to skin and intestinal lining.

Answer: 3. Riboflavin – Slow rate of clotting of blood

Question 39. Carboxypeptidase is secreted by :

1. Pancreas
2. Lining of intestine
3. Salivary glands
4. Stomach.

Answer: 1. Pancreas

Question 40. Which group of three of the following five statements (a-e) contains all three correct statements regarding bribery?

1. A crippling disease prevalent among the native population of sub-Saharan Africa;
2. A deficiency disease caused by lack of thiamine (vitamin B1);
3. A nutritional disorder in infants and young children when the diet is persistently deficient in essential protein;
4. Occurs in those countries where the staple diet is polished rice;
5. The symptoms are pain from neuritis, paralysis, muscle wasting, progressive oedema, mental deterioration and finally heart failure;

1. 1, 2 and 4
2. 2, 3 and 5
3. 1, 3 and 5
4. 2, 4 and 5

Answer: 4. 2, 4 and 5

Question 41. A patient is generally advised to consume especially more meat, lentils, milk and eggs in the diet only when he suffers from :

1. Kwashiorkor
2. Scurvy
3. Anaemia
4. Rickets.

Answer: 1. Kwashiorkor

Question 42. Secretin and cholecystokinin are digestive hormones. They are secreted in :

1. Oesophagus
2. Ileum
3. Duodenum
4. Pyloric stomach.

Answer: 3. Duodenum

Question 43. Epithelial cells of the intestine involved in food absorption have on their surface :

1. Pinocytic vesicles
2. Microvilli
3. Zymogen granules
4. Phagocytic vesicles.

Answer: 2. Microvilli

Question 44. enzymes, vitamins and hormones can be classified into a single category of biological chemicals because all of these :

1. help in regulating metabolism
2. are exclusively synthesized in the body of a living organism
3. are conjugated proteins
4. enhance oxidative metabolism.

Answer: 1. help in regulating metabolism

Question 45. HCL is secreted by :

1. zymogen cells
2. peptic cell
3. oxyntic cells
4. None of these.

Answer: 3. oxyntic cells

Animal Nutrition And Digestive System NEET Notes

Question 46. Which of the following vitamins is water soluble as well as anti-oxidant?

1. Vit B₁
2. Vit A
3. Vit D
4. Vit C.

Answer: 4. vit C

Question 47. The given graph shows the effect of substrate concentration on the rate of reaction of the enzyme green-gram-phosphatase. What does the graph indicate?

1. The rate of enzyme reaction is directly proportional to the substrate concentration
2. Presence of an enzyme inhibitor in the reaction mixture
3. Formation of an enzyme-substrate complex
4. At higher substrate concentration the pH increases.

Answer: 2. Presence of an enzyme inhibitor in the reaction mixture

Question 48. Which one of the following four secretions is correctly matched with its source, target and nature of action?

Answer: 1.

Question 49. Maltase converts,

1. maltose to glucose at pH greater than 7
2. maltose to glucose at a pH lesser than 7.0
3. maltose to alcohol
4. starch to maltose at pi 1 higher than 7.0,

Answer: 1. Maltose to glucose at pi I greater than 7

Question 50. Which pair is essential for the growth of first in water?

1. calcium and phosphorus
2. phosphates and carbonates
3. sulphate and carbonates
4. nitrates and sulphates.

Answer: 1. calcium and phosphorus

Question 51. Match the following nutritional vitamin deficiencies in column 1 with the causes/deficiencies in column 2 and choose the correct option from the answer key.

1. A = p, B = t, C = q, D = r, E = s
2. A = t, B = q, C = r, D = s, E = p
3. A = t, B = r, C = s, D = p, E = q
4. A = r, B = s, C = p, D = t, E = q.

Answer: 4. A = r, B = s, C = p, D = t, E = q

Question 52. The main function of lacteals in the villi of human small intestine is the absorption of:

1. amino acids and glucose
2. glucose and vitamins
3. water and mineral salts
4. fatty acids and glycerol.

Answer: 4. fatty acids and glycerol

Question 53. Which of the following is called a detritivore?

1. an animal feeding on decaying organic matter
2. an animal feeding on a plant
3. a plant feeding on an animal
4. an animal feeding on another animal.

Answer: 1. an animal feeding on decaying organic matter

Question 54. Which one of the following enzymes carries out the initial step in the digestion of milk in humans?

1. Pepsin
2. Rennin
3. Lipase
4. Trypsin.

Answer: 2. Rennin

Human Digestive System NEET Biology

Question 55. Examination of the blood of a person suspected of having anaemia shows large, immature, nucleated erythrocytes without haemoglobin. Supplementary his diet with which of the following, is likely to alleviate his symptoms?

1. Riboflavin
2. Iron compounds
3. Thiamine
4. Folic acid and cobalamine.

Answer: 4. Folic acid and cobalamine

Question 56. Which of the following pairs of the kind of cells and their secretion is correctly matched?

1. oxyntic cells – a secretion with pH between 2.0 and 3.0
2. alpha cells of islets of Langerhans – secretion that decreases blood sugar level
3. Kupffer cells – a digestive enzyme that hydrolyses nucleic acids
4. sebaceous glands a socialism trial evaporates on cooling,

Answer: 1. oxyntic cells – a secretion with pH between 2.0 and 3.0

Question 57. The following is a scheme showing the rate of carbohydrate timing digestion in the human alimentary canal. Identify the enzymes acting at stages indicated as a, b, c and d. Choose the convict option from those given

1. a = amalyse, b = maltase, c = lactase, d = invertase
2. a = amylase, b = maltase, c = invertase, d = lactase
3. a = amylase, b = invertase, c = maltase, d = lactase
4. a = amylase, b = lactase, c = maltase, d = invertase.

Answer: 4. a = amylase, b = lactase, c = maltase, d = invertase.

Question 58. Which one is correctly matched?

1. vitamin E-thiamine
2. vitamin D-riboflavin
3. vitamin B₁ -tocopherol
4. vitamin A-calciferol
5. vitamin B₁₂-cyanocobalamine.

Answer: 5. vitamin B₁₂-cyanocobalamine

Question 59. Which of the following is the correct chronological order for enzyme activity of some enzymes taking part in protein digestion?

1. pepsin→ trypsin -4 peptidase
2. pepsin →peptidase →trypsin
3. trypsin → pepsin → peptidase
4. peptidase → trypsin → pepsin

Answer: 1. pepsin →trypsin -4 peptidase

Question 60. Which of the following can be absorbed by hepatic caeca?

1. glucose and amino acid
2. glucose and lipid
3. lipid
4. glucose.

Answer: 4. glucose

Question 61. Which of the following hormones helps in the secretion of HCL from the stomach?

1. renin
2. gastrin
3. secretin
4. somatomedin,

Answer: 2. gastrin

Human Digestive System NEET Biology

Question 62. Statements

1. The element which is very important for the production of thyroxine is iodine
2. Vitamin B₆ is otherwise known as niacin or nicotinic acid
3. Fructose is a monosaccharide and is a hexose sugar
4. Globulin is an example of a conjugated protein of the above statements.

1. 1, 2 and 3 are correct but 4 is wrong
2. 1 and 3 are correct but 2 and 4 are wrong
3. 1 and 2 are correct but 3 and 4 are wrong
4. 1 is correct while 2, 3 and 4 are wrong
5. 1, 3 and 4 are correct but b is wrong.

Answer: 2. 1 and 3 are correct but 2 and 4 are wrong

Question 63. ‘Crypts of Liebcrkuhn’ are found in :

1. gall bladder
2. liver
3. pancreas
4. intestinal tracts
5. salivary glands.

Answer: 4. salivary glands

Question 64. Glisson’s capsule is associated with

1. liver
2. pancreas
3. lung
4. Kidney.

Answer: 1. liver

Question 65. The main digestive function of enterokinase is :

1. conversion of casein into paracasein
2. conversion of pepsinogen into pepsin
3. conversion of trypsinogen into trypsin
4. Stimulation of the gastric glands to secrete gastric juice
5. conversion of trypsin into trypsinogen.

Answer: 3. conversion of trypsinogen into trypsin

Question 66. Which of the following is the correct matching of the site of action on the given substrate, the enzyme acting upon it and the end product?

Answer: 3

Question 67. What will happen if the secretion of parietal cells of the gastric glands is blocked with an inhibitor?

1. Gastric juice will be deficient in chymosin
2. Gastric juice will be deficient in pepsinogen
3. In the absence of HCL secretion, inactive pepsinogen is not converted into the active enzyme pepsin
4. Enterokinase will not be released from the duodenal mucosa so trypsinogen is not converted to trypsin.

Answer: 3. In the absence of HCL secretion, inactive pepsinogen is not converted into the active enzyme pepsin

Question 68. Anxiety and eating spicy food together in an otherwise normal human may lead to:

1. Jaundice
2. Diarrhoea
3. Vomiting
4. indigestion.

Answer: 4. indigestion

Question 69. Select the correct match of the digested products in humans given in column 1 with their absorption site and mechanism in column 2. ‘

Answer: 4.  Glycine, Glucose – Small Intestine, Active absorption

NEET Biology Respiration In Plants Multiple Choice Questions

Question 1. While a muscle is in the process of reducing an oxygen debt :

1. Lactate is converted into pyruvate
2. All the NAD* is in the reduced form
3. Pyruvate is converted into lactate
4. NADH acts as an oxygen acceptor.

Answer: 1. Lactate is converted into pyruvate

Question 2. NAD functions in cell respiration as a (an):

1. energy currency
2. enzyme
3. coenzyme
4. hydrogen donor.

Answer: 3. coenzyme

Question 3. Which of the following statements about oxidative phos¬phorylation is not true?

1. More of the ATP in a normal cell is formed by oxidative phosphorylation via the electron transport chain than by substrate-level phosphorylation UJ;
2. In eukaryotes, the formation of ATP by oxidative phosphorylation requires that the inner mitochondrial membrane remains intact
3. NAD is a carrier molecule that travels down the electron transport chain to release ATP during oxidative phosphorylation
4. In eukaryotes, the electron transport chain and the enzymes of the citric acid cycle are located in nvmitoc- conidia whereas the enzymes of glycolysis are located in the cytoplasm
5. The role of oxygen is to act as an acceptor for electrons.

Answer : 3. In eukaryotes, the electron transport chain and the enzymes of the citric acid cycle are located in nvmitoc- conidia whereas the enzymes of glycolysis are located in the cytoplasm

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 4. Transfer of energy in animal cells is in the form of:

1. ATP
2. ADP
3. Protein
4. Monohexose phosphate.

Answer: 1. ATP

Respiration in Plants NEET Practice Questions Question 5. Directly largest amount of phosphate bond energy is produced in the process of respiration during the:

1. Glycolysis
2. Anaerobic respiration
3. Krebs’ cycle
4. Fermentation.

Answer: 1. Glycolysis

Question 6. The end products of Krebs’ cycle are :

1. 3 (NADH2), 1 FADH2,2 GTP
2. 4(NADH2),1GTP
3. 2 (NADH2), 2(FADH2), 1 GTP
4. 3 (NADH2), 1 (FADH2), 1 GTP.

Answer: 4. 3 (NADH2), 1 (FADH2), 1 GTP.

Question 7. One NADH2 yields how many ATP molecules?

1. Three
2. Six
3. Four
4. One.

Answer: 1. Three

Question 8. Acetyl Co-A combines with which of the following compounds to form citric acid :

1. Oxalosuccinic acid
2. Oxaloacetic acid
3. Citric acid
4. Ketoglutaric acid.

Answer:  2. Oxaloacetic acid

Question 9. Respiratory quotient (RQ) is represented by C02/02 and R.Q. for organic acid is :

1. more than one
2. less than one
3. One
4. infinity.

Answer: 1. more than one

Question 10. Oxidative phosphorylation is the formation of :

1. NADPH2 in respiration
2. ATP in respiration
3. NADH2 in photosynthesis
4. ATP in photosynthesis.

Answer: 2. ATP in respiration

Respiration in Plants NEET Practice Questions Question 11. In the process of respiration, the potential energy stored in organic compounds is released in the form of:

1. physical energy
2. chemical energy
3. kinetic energy
4. radiant energy.

Answer:  2. chemical energy

Question 12. Glycolysis operates in :

1. cytoplasm
2. endoplasmic reticulum
3. perinuclear space
4. Golgi body.

Answer: 1. cytoplasm

Question 13. The process of respiration which results in the formation of pyruvic acid is :

1. phosphorylation
2. glycolysis
3. photorespiration
4. Krebs’ cycle.

Answer: 2. glycolysis

Question 14. Respiratory Quotient (R.Q.) is the ratio of:

1. 02 consumed to C02 evolved
2. water and C02
3. carbohydrates and 02
4. C02 evolved and 02 was consumed.

Answer: 4. C02 evolved and 02 was consumed.

Question 15. In anaerobic respiration, the end product is :

1. starch
2. pyruvic acid
3. sugar
4. ethyl alcohol and C02.

Answer: 4. ethyl alcohol and C02.

Question 16. Energy-rich compounds produced in respiration are:

1. adenosine diphosphate
2. adenosine triphosphate
3. adenosine monophosphate
4. adenosine acetate.

Answer: 2. adenosine triphosphate

Respiration in Plants NEET Practice Questions Question 17. One molecule of glucose on complete oxidation releases how much energy?

1. 2870 KJ
2. 1292 KJ
3. 247 KJ
4. 3800 KJ.

Answer: 1. 2870 KJ

Question 18. Which mineral acts as an activator in isocitric acid de-hydrogenase enzyme in Krebs’ cycle?

1. Mn
2. Fe
3. Mg
4. Mo.

Answer: 3. Mg

Question 19. During complete aerobic respiration, how much ATP is gained in prokaryotes?

1. 40 ATP
2. 8 ATP
3. 38 ATP
4. 24 ATP.

Answer: 3. 38 ATP

Question 20. In proteins, R.Q. value is:

1. Less than unity
2. More than unity
3. Zero
4. Unity.

Answer: 1. Less than unity

Question 21. The inner membranes of mitochondria and chloroplasts :

1. are relatively permeable to H+
2. have ATP enzymes attached to one face only
3. contain molecules of the electron transport system
4. All the above.

Answer: 4. All the above.

Question 22. K (J is found to be always unity in :

1. Fats
2. carbohydrates
3. proteins
4. organic acids.

Answer: 2. carbohydrates

Respiration In Plants MCQ For NEET Biology Question 23. How much ATP is produced during anaerobic respiration?

1. 8 ATP
2. 2 ATP
3. 5 ATP
4. 6ATP.

Answer: 2. 2 ATP

Question 24. If naked peas sce<ls are kept in four respiratory flasks then they would germinate best if the flask contains :

1. C02
2. N2
3. 02
4. H2

Answer: 3. 02

Question 25. What is the link between glycolysis and Krebs’ cycle?

1. oxaloacetic acid
2. Acetyl CoA
3. citric acid
4. pyruvic acid.

Answer: 2. Acetyl CoA

Question 26. Name the scientist who found how the energy of glucose was released in aerobic respiration.

1. Pasteur
2. Calvin
3. Krebs
4. Hopkins

Answer: 3. Krebs

Question 27. In glycolysis the net gain is two ATP molecules and two molecules are released:

1. NAD
2. FADH
3. NADH2
4. FAD.

Answer: 3. NADH2

Question 28. The scries of reactions in the TCA cycle take place in :

1. ribosome
2. grana
3. mitochondria
4. endoplasmic reticulum.

Answer: 3. mitochondria

Question 29. In the Krchs’ cycle, citric acid is activated by :

1. aconitase
2. malate dehydrogenase
3. succinyl coenzyme A
4. coenzyme A.

Answer: 1. aconitase

Respiration In Plants MCQ For NEET Biology Question 30. In the ‘FCA cycle, the acid reacts with acetyl coenzyme A:

1. fumaric acid
2. succinic acid
3. oxaloacetic acid
4. malic acid.

Answer : 3. oxaloacetic acid

Question 31. Oxidative phosphorylation is the synthesis of :

1. ADI* during the aerobic respiration
2. NADP during the anaerobic respiration
3. ATP during aerobic respiration
4. phytochrome.

Answer: 3. ATP during the aerobic respiration

Question 32. When two molecules of Tripalmitin are used as a respiratory substrate the RQ is:

1. 4
2. 0.7
3. 1
4. Infinity.

Answer: 2. 0.7

Question 33. Glucose is converted into pyruvic acid through a series of reactions with a net gain of: ,

1. 2 molecules of ATP
2. 36 molecules of ATP
3. 4 molecules of ATP
4. 38 molecules of ATP.

Answer: 1. 2 molecules of ATP

Question 34. The maximum rate of respiration in many plants of the tropics can be observed in the range of:

1. ()°C—25°C
2. 20° C to 45° C
3. 60°C—IOO°C
4. Above 100° C.

Answer: 2. 20° C to 45° C

Question 35. In woody stems, respiration takes place through :

1. pores
2. stomata
3. lenticels
4. injured parts.

Answer: 3.  lenticels

Respiration In Plants MCQ For NEET Biology Question 36. During ATP synthesis electrons pass through :

1. phytochromes
2. cytochromes
3. water
4. oxygen.

Answer: 2. cytochromes

Question 37. R.Q. for Oxalic acid is :

1. 4
2. I
3. Infinity
4. 0.9.

Answer: 1. 4

Question 38. In plants glucose used as a respiratory substrate is derived from :

1. starch
2. maltose
3. sucrose
4. galactose.

Answer: 3. sucrose

Question 39. During glycolysis, fructose 1,6 biphosphate is produced by the action of which enzyme?

1. Mutase
2. Phospho fructokinase
3. Invcrtasc
4. Hexokinase.

Answer: 2. Phospho fructokinase

Question 40. In the conversion of pyruvic acid to C02, which does not take place :

1. pyruvic acid to succinic acid
2. pyruvic acid to lactic acid
3. pyruvic acid to malic acid
4. None of these.

Answer: 1. pyruvic acid to succinic acid

Question 41. The function of cellular respiration is to :

1. make NADH
2. make ATP
3. gel rid of glucose
4. get rid of C02

Answer: 4. get rid of C02

Question 42. It is not advisable to sleep under trees at night because :

1. They release 02 at night.
2. They release C02 at night.
3. They release both CO-> and 02 at night
4. They produce none of the above.

Answer: 2. They release C02 at night.

Question 43. The function of mitochondrial cristae is to.

1. increase the availability of phospholipids
2. store coenzyme A
3. increase the surface area of the inner membrane
4. prevent the escape of 0-> gas.

Answer : 3. increase the surface area of the inner membrane

Respiration in Plants Biology for NEET Question 44. The number of molecules of pyruvic acid formed from one molecule of glucose at the end of glycolysis is :

1. 1
2. 2
3. 3
4. 4.

Answer: 2. 2

Question 45. Oxidative phosphorylation takes place on :

1. grana
2. crista
3. mitochondrial matrix
4. ribosomes.

Answer: 3. mitochondrial matrix

Question 46. Which among the following is the most appropriate rea¬-‘ son for storing green-colored apples at low temperatures?

1. The rate of respiration is reduced
2. The rate of photosynthesis is reduced
3. The rates of photosynthesis and respiration are reduced
4. Respiration and photosynthesis are completely inhibited.

Answer: 2. The rate of photosynthesis is reduced

Question 47. The other name of Glycolysis is :

1. BMP pathway
2. TCA pathway
3. I IMP pathway
4. None of the above.

Answer: 1. BMP pathway

Question 48. One molecule of ATP yields how much energy?

1. 8.9 K cal
2. 6.5 K cal
3. 34KJ
4. 3.4 KJ.

Answer: 3. 34KJ

Respiration in Plants Biology for NEET Question 49. In which kind of plants CO, compensation is usually higher:

1. C4 plants
2. C3 plants
3. CAM plants
4. None of the above.

Answer: 3. CAM plants

Question 50. ATP is:

1. an enzyme that brings about oxidation
2. a hormone
3. a molecule with high energy phosphate bond
4. a protein.

Answer: 3. a molecule with high energy phosphate bond

Question 51. Which of the following processes make direct use of oxygen?

1. Glycolysis
2. Fermentation
3. Krebs’ citric acid cycle
4. Electron transport.

Answer: 4. Electron transport.

Question 52. Which of the following is not true of glycolysis?

1. Substrate-level phosphorylation takes place
2. CO and 11,0 are end products
3. ATP is generated
4. ATP is used.

Answer: 2. CO, and 11,0 are end products

Question 53. When a yeast is producing wine, which of the following is not produced?

1. Pyruvic acid
2. Ethanol
3. CO,
4. Acetyl Co A.

Answer: 4. Acetyl Co A.

Question 54. In the conversion of pyruvic acid to acetyl CoA, pyruvic acid is :

1. oxidized
2. reduced
3. broken into one carbon fragment
4. isomerized.

Answer: 2. reduced

Question 55. The function of coenzyme A is to :

1. isomerize pyruvic acid
2. isomerize NAD
3. activate acetyl group
4. facilitate oxidative phosphorylation.

Answer: 3. activate acetyl group

Question 56. How many carbon atoms are in an oxaloacetic acid molecule, which joins with an acetyl group during step 1 of the Kerbs’ citric acid cycle?

1. 6
2. 4
3. 3
4. 2.

Answer: 2. 4

Respiration in Plants Biology for NEET Question 57. At the end of the Krebs’ citric acid cycle, most of the energy removed from glucose molecule has been transferred to :

1. Citric acid
2. Oxaloacetic acid
3. ATP
4. NADH2 and FADH2

Answer: 2. Oxaloacetic acid

Question 58. In ETS, the final acceptor of protons is :

1. Cyt. b
2. Cyt. a3,
3. Oxygen
4. Ubiquinone (substance).

Answer: 3. Oxygen

Question 59. The atom within each cytochrome molecule that actually accepts and releases electrons is :

1. Carbon
2. Iron
3. Zinc
4. Oxygen.

Answer: 2. Iron

Respiration in Plants Biology for NEET Question 60. Oxygen which forms part of the ETS, enters the mitochondrion as an atom in :

1. Glucose
2. Pyruvic acid
3. C02
4. Oxygen gas.

Answer: 4. Oxygen gas.

Question 61. Fatty acids enter cellular respiration as :

1. one carbon fragment
2. two carbon fragments
3. long chains of 16-20 carbon atoms
4. three-carbon fragments.

Answer: 2. two carbon fragments

Question 62. Within the mitochondrion, the proton gradient develops across the :

1. inner membrane
2. outer membrane
3. intermembrane space
4. matrix.

Answer: 3. intermembrane space

Respiration in Plants NEET Questions MCQ Question 63. Match the items in Column 1 with those in Column 2 :

1. (1—E), (2—B), (3—D). (4—A), (5—C)
2. (1—A). (2—C). (3—A). (4—D), (5—C)
3. (1—B), (2—D), (3—A). (4—E), (5—C)
4. (1—B), (2—C). (3—D), (4—A), (5—E),

Answer: 2. (1—A). (2—C). (3—A). (4—D), (5—C)

Question 64. Which is true for glycolysis under aerobic conditions?

1. Only ATP is produced
2. Only NADH2 is produced
3. Both ATP and NADH2 arc produced
4. Neither ATP nor NADH is produced.

Answer: 3. Both ATP and NADH2 arc produced

Question 65. Which is not true for the TCA cycle when one acetyl group is oxidized?

1. Two CO, molecules are released
2. Three NADf molecules and one FAD molecule are reduced
3. One GTP molecule is produced
4. 38 ATP molecules are produced.

Answer: 4. 38 ATP molecules are produced.

Question 66. An organism which does not produce water as a waste of the respiratory process is likely to be :

1. green plant
2. autotroph
3. anaerobe
4. aerobic organism.

Answer: 3. anaerobe

Question 67. A high concentration of oxygen above 25% :

1. reduces respiration
2. increases respiration
3. does not have any effect
4. leads to the bursting of cells.

Answer: 1. reduces respiration

Question 68. If CO, is given off in respiration, why does the amount of CO, in the atmosphere remain relatively constant?

1. CO, forms carbonate rocks
2. CO is a buffer
3. CO is converted in photosynthesis to carbohydrates
4. CO is split up during photosynthesis.

Answer: 3. CO, is converted in photosynthesis to carbohydrates

Question 69. How many molecules of ATP are produced directly from one molecule of glucose during glycolysis :

1. 6
2. 8
3. 0 2
4. 38.

Answer: 3. 0 2

Respiration in Plants NEET Questions MCQ Question 70. In ETS, complex IV refers to :

1. succinate dehydrogenase
2. cytochrome oxidase
3. ATP synthetase
4. Ubiquinone.

Answer: 2. cytochrome oxidase

Question 71. Sir Hans Adolf Krebs (1900-1987) shared the Nobel Prize for Physiology and Medicine (1953) along with :

1. A. Todd.
2. 11. Theorell.
3. Fritz Lipmann
4. Linus Pauling.

Answer: 3. Fritz Lipmann

Question 72. The end product of the fermentation of sugars by Psuedomoiuts bacteria is :

1. lactic acid and alcohol
2. CO2
3. ethyl alcohol +C02
4. butyl alcohol.

Answer: 1. lactic acid and alcohol

Question 73. Which of these is not true for fermentation?

1. NADH donates electrons to the ETS
2. beginning with glucose
3. Net gain of only 2 ATP
4. Occurs in cytosol.

Answer: 1.

Question 74. Protein-rich pulses have R.Q. equal to :

1. One
2. More than one
3. Less than one
4. None of the above.

Answer: 3. Less than one

Question 75. The mineral activator needed for the enzyme carboxylase of the TCA cycle is :

1. Mg
2. Fe
3. Mo
4. Mn

Answer: 1. Mg

Respiration in Plants NEET Questions MCQ Question 76. A huge amount of starch is stored in potatoes, which are underground. This is made possible by :

1. Synthesis of sugar in potatoes
2. Migration of starch from aerial parts to the tubers
3. Migration of starch from dead soil into the tubers
4. The activity of enzymes that convert starch into sugar and back to starch after it has reached the potato.

Answer: 4. Activity of enzymes that convert starch into sugar and back to starch after it has reached the potato.

Question 77. Which of the following leaves will show the maximum rate of respiration?

1. Young leaves
2. Mature leaves
3. Senescent leaves
4. None of these.

Answer: 1. Young leaves

Question 78. Respiration in methane-forming bacteria and de-nitric-flying bacteria is :

1. Aerobic
2. Facultative aerobic
3. Facultative anaerobic
4. Obligatory anaerobic.

Answer: 4. Obligatory anaerobic.

Question 79. During respiration, there are:

1. gain in the dry weight
2. loss in the dry weight
3. no change in the dry weight
4. all the above are correct depending on the type of respiratory substrate.

Answer: 2. loss in the dry weight

Question 80. In animal cells, the first phase in the breakdown of glucose is :

1. Fermentation
2. ETS
3. Krebs’ cycle
4. Glycolysis.

Answer: 4. Glycolysis.

Respiration in Plants NEET Questions MCQ Question 81. A molecule of ATP is formed when an electron passes from :

1. Cyt. c to Cyt. a
2. Cyt. b to Cyt. c
3. Cyt. a to Cyt. c
4. Cyt. c to Cyt b.

Answer: 2. Cyt. b to Cyt. c

Question 82. Most of the energy is supplied by mitochondria through :

1. Breakdown of proteins
2. Reduction of NADP
3. Breakdown of sugars
4. Oxidizing TCA substrates.

Answer: 4. Oxidising TCA substrates.

83. The end product of glycolysis is :

1. Glucose
2. Pyruvic acid
3. Ethyl alcohol
4. Carbon dioxide.

Answer: 2. Pyruvic acid

Question 84. Which is the link between glycolysis and Krebs’ cycle :

1. Glucose
2. Cytochrome
3. Acetyl Co A
4. Pyruvic acid.

Answer: 3. Acetyl Co A

Question 85. The end products of fermentation are :

1. 02 and ethyl alcohol
2. 02 and acetaldehyde
3. C02 and ethyl alcohol
4. C02 and acetaldehyde.

Answer: 3. C02 and ethyl alcohol

Question 86. In eukaryotes, a net gain of ATP in the complete oxidation of one molecule of glucose is:

1. 20 ATP
2. 36 ATP
3. 38 ATP
4. 56 ATP.

Answer: 2. 36 ATP

Question 87. In ETS, which is the cytochrome that reacts with oxygen?

1. Cyt a
2. Cyt b
3. Cyt b6
4. Cyt a3

Answer: 4. Cyt a3

Question 88. Instantaneous sources of energy are:

1. Starch
2. Protein
3. Glucose
4. Sucrose.

Answer: 3. Glucose

Question 89. R.Q. is less than one in succulent plants because of:

1. incomplete reduction
2. complete reduction
3. incomplete oxidation
4. complete oxidation.

Answer: 3. incomplete oxidation

Respiration In Plants MCQ For NEET Biology  Question 90. Oxidative phosphorylation is the formation of :

1. NADPH2 in respiration
2. ATP in respiration
3. NADPH2 in photosynthesis
4. ATP in photosynthesis.

Answer: 2. ATP in respiration

Question 91. In hexose monophosphate shunt the number of C02 molecules evolved is :

1. Same as in glycolysis
2. Less than glycolysis
3. More than glycolysis
4. Much less than glycolysis.

Answer: 3. More than glycolysis

Question 92. Which of the following observations most strongly support the view that mitochondria contain electron-transfer enzymes aggregated into compact associations?

1. A contractile protein capable of utilizing ATP has been obtained from mitochondria
2. Mitochondria have a highly folded inner wall
3. Disruption of mitochondria yields membrane fragments which are able to synthesize ATP
4. Mitochondria in animal embryos have a tendency to concentrate in cells which become part of locomotory structures.

Answer: 3. Disruption of mitochondria yields membrane fragments which are able to synthesize ATP

Question 93. Maximum energy becomes available per mole of glucose when it is metabolized through :

1. Glycolysis in the skeletal muscle of a sprinter
2. Fermentation into ethanol by yeast
3. Fermentation into methanol by enteric bacteria
4. Aerobic respiration.

Answer:  4. Aerobic respiration

NEET Biology Respiration In Plants

NEET Biology Respiration In Plants Respiration

• Living organisms require energy in order to maintain their chemical composition, and movement, repair of damaged parts, grow, and reproduce.
• Photosynthesis and respiration are the central energy-processing pathways of life.
• The ultimate task of both processes is to produce energy intermediates to drive endergonic reactions.
• These energy intermediates in living cells have phosphate groups attached by so-called high-energy phosphate bonds.
• ATP (Adenosine triphosphate) is the energy intermediate or energy currency in every living organism.
• UTP and GTP are other common energy intermediates.
• Energy is usually released from ATP by hydrolyzing the terminal phosphate group, yielding ADP and inorganic phosphate group iP and about 8.9 kilo calories of energy per mole of ATP hydrolyzed.
• ADP may be further hydrolyzed to form AMP and iP and 6.5 Kcal. of energy per mol.
• ATP is resynthesized during phosphorylation. It is of three types: Photophosphorylation, oxidative phosphorylation, and substrate-level phosphorylation.
• By weight each gram mol of glucose and fat yields 4.1 and 9.3 Kcal of biological energy respectively.
• Complete combustion of glucose molecules in a calorimeter, into CO₂ and H₂O yields about 686,000 calories (686 Kcal.) of heat energy.
• In biological oxidation, a glucose molecule yields 38 molecules of ATP ( 36 molecules of ATP in eukaryotes).
• Biological systems are capable of utilizing only about 40% of chemical energy stored in glucose, the remaining is lost as heat

Read and Learn More NEET Biology Notes

NEET Biology Respiration In Plants Broad Outline Scheme Of Respiration

• Respiration is the process in which there is a breakdown of complex substances into simple substances with the evolution of energy. If the breakdown occurs in the presence of oxygen then it is aerobic respiration.

In this kind, the breakdown is complete and a lot of energy is released. On the other hand, in anaerobic respiration, as O₂ is not needed, the breakdown is incomplete and less energy is released.

Respiration In Plants NEET Notes

• During aerobic respiration, pyruvic acid is formed from glucose in the first step. The various reactions take place in the cytoplasm. This step is called glycolysis.

Pyruvic acid enters mitochondria and changes into Acetyl COA which then enters Krebs’ cycle in mitochondria to produce H-,0 and CO^–, NADH-, and FADH, produced in Krebs’ cycle enter ETS to release ATP molecules (energy source). There”is terminal oxidation and oxidative phosphorylation.

NEET Biology Respiration In Plants Glycolysis

NEET Biology Respiration In Plants Other Methods Of Formation Of Pyruvic Acid

In addition to the EMP pathway, pyruvic acid

Can also be formed by following metabolic pathways of carbohydrates :

• Hexose monophosphate pathway or shunt (HMP) Pentose phosphate pathway or 6-Phosphogluconate pathway
• Phosphoketolase pathways.
• Entner-Duodoroff (ED) pathway.
• Hexose monophosphate pathway (HMP):

 Pathway Definition:

This is a multifunctional process primarily designed to produce reducing power in the form of NADPH, which acts as a donor of hydrogen and electrons in several reductive biosynthetic pathways, including in the synthesis of fatty acids and steroids.

• The HMP details were provided by Warberg and Dickens, so it is referred to as the YVarberg-Dickens pathway. Event.
• It is present in various animal tissues, including the liver (phospholipid synthesis), mammary glands (milk fat synthesis), adipose tissue (fatty acid synthesis), erythrocytes, adrenal cortex, and other endocrine glands associated with steroid hormone synthesis. It is lacking in the muscle cells. It also transpires in the

 Pathway Properties:

1. In HMP, ATP is neither consumed nor produced.
2. It occurs in the extramitochondrial cytoplasm which has all the enzymes of HMP.
3. In this, hexoses arc is converted into pentoses, especially ribose-5-P.
4. It is also called the direct oxidative pathway because in this C-l of glucose is oxidized first (In glycolysis, C₃ and C₄ are first oxidized),
5. The co-enzyme used in oxidative reactions of HMP is NADP+ which is reduced to NADPII + H+ (In glycolysis, the H-acceptor used is NAD+).
6. CO₂ is produced.

Significance Of Ppp

1. It provides an alternative route other than glycolysis for carbohydrate breakdown.
2. It provides the erythrose-4-phosphate required for the synthesis of shikimic acid. It is the precursor of an aromatic ring compound.
3. It generates NADPII molecules which are used as reductants in biosynthetic processes under conditions when NADPH molecules are not generated by photosynthesis.
4. It is, therefore, important in non-photosynthetic tissues such as in differentiating tissues, germinating seeds, and during periods of darkness. Production of NADPH is not linked to ATP generation in the pentose phosphate pathway.
5. It provides ribose sugar for the synthesis of nucleic acids.
6. It plays an important role in the fixation of CO₂.

Glycolysis And Krebs Cycle NEET Study Material

NEET Biology Respiration In Plants Oxidation Of Pyruvic Acid Formation of Acetyl Co-A

The Acetyl Co A is the connecting link between glycolysis and Krebs’ cycle.

NEET Biology Respiration In Plants Electron Transport System Ets Or Cytochrome System Cs

Cytochromes identified by Mac Cunn are intrinsic proteins abundant in iron (Fe+2). Cyt a3 contains both Cu²⁺ and Fe²⁺ and functions as cytochrome oxidase.

• It is the primary energy source within a cell. It additionally regenerates coenzymes and creates water. The hydrogen atom pairs that dissociate from the prior processes do not directly combine with oxygen to produce water; instead, they first traverse a sequence of seven intermediate carriers situated on the inner mitochondrial membrane, including the cristae.
• The transfer of electrons releases energy at three stages during the enzymatic binding of ADP and inorganic phosphate to produce ATP. The mechanism of energy storage via electron transport in the phosphate bond of ATP is termed oxidative phosphorylation.

The sequence of electron carriers is :

1. NADH₂ → FMN -V FeS

→ CoQ → Cyt b →Cyt c

1. → Cyt a-a₃ oxygen.

ATP Synthesis according to Chemisoniatic hypothesis (Peter Mitchell 1979).

• It involves the passage of 2e from NADH₂ pushing out three pairs of protons from the inner to the outer chamber of mitochondria resulting in proton gradient and electric potential.
• These two jointly create a proton motive force. It causes the proton to move back through proton channels of F₀ particles. Energy is made available to F₀ particles for the synthesis of ATP as these particles have ATP activity

NEET Biology Respiration In Plants Factors Affecting Respiration In Plants

External Factors :

1. Light. Light has no direct effect, however, the respiration rate is higher in sunlight than in darkness.
2. Temperature. Respiration is maximum at 30°C. Above this temperature respiration rate decreases due to denaturation of enzymes. At low temperatures (zero or below zero) the enzymes become inactive and thus respiration decreases.
3. Low temperatures in cold storage are useful in storing food grains, and vegetables. In hilly areas, the temperature is low at night and moderate during the day causing reduced respiration and high photosynthesis.
4. According to Vant Hoffs law, the rate of respiration increases 2-2.5 times with every 10°C increase in temperature between 0-25°C, i.e. Q10 = 2-2.5 (cascade effect).
5. Oxygen. It is essential for aerobic respiration. A high concentration of O₂ inactivates the respiratory enzyme and reduces respiration. Oxygen also inhibits the fermentation of sugar by yeast cells or anaerobic respiration (Pasteur effect).
6. Carbon dioxide. Respiration decreases with increases in CO₂ concentration. High CO₂ concentration causes stomatal closure and checks the intake of O₂. Thus reduces respiration.
7. Water. Water is essential for enzyme activity. Respiration will not occur in the absence of oxygen. This is the reason that dry seeds with 8-12% moisture do not germinate unless watered.
8. Wound and injuries. For healing the injured areas, respiration is increased.
9. Chemicals. Cyanide and carbon monoxide inhibit respiration.

Electron Transport Chain In Plants NEET Important Points

Internal Factors: Protoplasm. (Meristematic) cells with dense protoplasm have a high rate of respiration.

1. Substrate. The rate of respiration is directly proportional to the amount of substrate. Respiration decreases if end products accumulate.

Outline of ATP production during aerobic oxidation of glucose to CO₂ and H₂O

GLYCOLYSIS

• ATP produced directly    ….4 molecules
• ATP consumed             …. 2 molecules
• Net gain of ATP          … 2 molecules
• From hydrogen produced and sent down the electron transport system Route II and Route I (2 x 2) / (2 x 3) respectively       4/6 molecules

Pyruvic Acid Oxidation

• From hydrogen produced and sent down the electron transport system (2×3)      6 molecules

Krebs’ Cycle (Tricarboxylic Acid Cycle)

• ATP produced directly (From GTP)      …. 2 molecules
• From hydrogen accepted by NAD (3 x 3)  ….9 molecules
• Therefore for the two molecules of citric acid metabolized (9×2)….18 molecules
• From hydrogens accepted by FAD (1×2)                           …. 2 molecules
• Thus for the two molecules of citric acid metabolized (2 x 2) …..4 molecules
• Total                                                         ..36/38 molecules

2 molecules of ATP consumed in transferring NADH into mitochondria in eukaryotes _2 molecules

Net gain of ATP in eukaryotes = 36 molecules

NEET Biology Respiration In Plants Anaerobic Respiration

The path for anaerobic respiration from glucose to pyruvic acid is the same as in aerobic respiration i.e. glycolysis.

• Pyruvic acid then forms ethyl alcohol and CO₂ or lactic acid. All these reactions occur in the cytoplasm and mitochondria are not involved.
• Fate of Pyruvic acid in anaerobic respiration. When there is no oxygen available to
  accept hydrogen atom, pyruvic acid (the end product of glycolysis) itself becomes the acceptor
  of hydrogen ions and protons.
• In animals, when cells are temporarily deprived of oxygen (as in skeletal muscles during exercise), pyruvic acid is converted into Inctic acid.
• In this reaction, NADH produced in glycolysis is oxidized into NAD⁺, and the two protons and two electrons So released are used in the conversion of pyruvic acid into lactic acid.
• The accumulation of lactic acid in the muscle causes fatigue. However, during rest, the lactic acid is again converted into pyruvic acid and undergoes aerobic respiration. Many bacteria obtain energy from glycolysis and convert pyruvic acid to lactic acid.

The net yield of ATP in anaerobic respiration.

There is a gain of only 2 molecules of ATP, that too, during glycolysis in anaerobic respiration. Production of much lesser ATP moleculeÿ, during anaerobic respiration is due to the following reasons-

1. Reactions do not proceed beyond glycolysis.
2. Even NADH produced in glycolysis is not channeled through the respiratory chain to produce ATP. Instead, it is used in the reduction of pyruvic acid.

Respiration In Plants NEET Mcqs With Answers

Fermentation differs from anaerobic respiration by the following features-

1. Fermentation is an extracellular process.
2. It usually occurs in microbes.
3. Enzymes extracted from cells perform fermentation.
4. A small quantity of oxygen rather stimulates fermentation while anaerobic respiration occurs in the absence of oxygen.

The energy stored during photosynthesis in carbohydrates In plants glucose is derived from sucrose. The latter such as glucose and starch, is released by breaking the C-C bonds of such molecules through oxidation for cellular use.

• This process of release of energy is called respiration.
• One molecule of glucose releases about 2870 KJ of energy during aerobic respiration and 247 KJ during anaerobic respiration.
• In plants, glucose is derived from sucrose. The latter is converted into glucose and fructose by an enzyme invertase and these two molecules readily enter the glycolysis pathway.
• The total energy yield from 38 molecules comes to 12c KJ (one ATP molecule yields 34 KJ of energy). Enter released in one molecule of glucose on complete oxidation corresponds to 2870 KJ. Tim the efficiency is 45 percent and the rest of the energy is lost as heat.
• In the bacterium Pseudomonas, glucose gives rise to pyru¬vic acid through the ED pathway. In this bacterium a molecule of glucose yields only one molecule of pyruvic acid. One ATP molecule is used and two are generated with a net gain of I ATP. Pyruvic acid is decarboxylated to acetaldehyde, which is then reduced to ethanol as in yeast.
• Plants show cyanide-resistant respiration because of an additional enzyme catalase which converts O₂ into water and oxygen. This respiration induces climacteric effect and atherogenicity

NEET Biology Respiration In Plants Quanta To Memory

1. Respiration is independent of light.
2. Photosynthesis is 10 times faster than respiration.
3. Efficiency of energy is 40-45%.
4. The term respiration was coined by Dutrocliet.
5. 264 gms of CO₂ is liberated during the complete oxidation of 180 gms. of glucose.
6. 88 gms of ethyl alcohol is formed by partial oxidation of 180 gms. of glucose.
7. 92 gms. of CO₂ is formed by anaerobic respiration of 180 gms of glucose.
8. All the respiratory substrates join a common scheme of oxidation, Krebs’ cycle.
9. All enzymes, substrates, intermediates, and end products of glycolysis are present in the cytosol.
10. Krebs cycle is the central pathway of cell respiration where the catabolic pathways converge upon it and anabolic pathways diverge from it.
11. The only high-energy phosphate produced in the Krebs cycle is GTP.
12. Glucose is the most common respiratory substrate.
13. During starvation, first glycogen, then, fats, and finally proteins are oxidized to liberate energy.
14. Ripening fruits show an increase in the rate of respiration (climacteric respiration)
15. F0 carries proton channels while F0 has ATP ase activity according to Mitchell’s chemiosmotic coupling theory.
16. Each pyruvic acid produces 15 ATP molecules in aerobic respiration while each Acetyl Co-A produces
17. 12 ATP molecules.
18. Krebs cycle is also called the Amphibolic process in which a number of intermediates of the Krebs cycle are used in anabolic pathways.
19. The ratio of ATP in aerobic and anaerobic respiration is 18.1 (36:2)
20. The ratio of C09 formation in aerobic and anaerobic respiration is 3:2.
21. Respiratory poisons are 2, 4 dinitrophenol, Antimycin-A, and cyanides.
22. Fats constitute the reserve energy and are used only after the consumption of carbohydrates. Proteins are used only after the consumption of both carbohydrates and fats.
23. Cytochromes are Fc-containing electron carriers except cytochrome which contains both Fe and Cu.
24. The pentose phosphate pathway: Also called hexose Monophosphate shunt, was explained by Warburg and Dickens. As a result of PPP, overall 35 ATP molecules are produced. It occurs in the cytosol. In the liver, this pathway is responsible for nearly 60% of the total carbohydrate oxidation,
25. Pasteur effect: Reduction in the amount of breakdown of the respiratory substrate and evolution of CO, when an anaerobically respiring material is brought into an O2-containing environment.
26. Dormant seeds represent a state of autooxidation.
27. Acetyl CoA is the common intermediate of carbohydrate and fat metabolism.
28. Fermentation was discovered by Gay Lussac.
29. The enzyme extracted from yeasts that brought about the fermentation is zymase.
30. RBCs and muscles get energy by glycolysis.
31. Fruits and seeds are stored at low temperatures to reduce the rate of respiration.
32. Viruses are infective agents that do not show the rate of respiration.
33. If a leaf is kept in a sugar solution, its rate of respiration increases.
34. The minimum concentration of O₂ for aerobic respiration extinction point is 3 – 10 %.
35. Dinitrophenol inhibits ATP synthesis (uncoupler of oxidative phosphorylation) but does not stop the transfer of electrons.
36. Oligomycin inhibits oxidative phosphorylation (energy transfer inhibitor).
37. Antimycin A stops the transfer of electrons from Cyt B to Cyt C and Cyanide prevents the transfer of electrons from cyt a3 to oxygen.

Respiration In Plants NEET Previous Year Questions

NEET Biology Respiration In Plants Questions For Competitive Examinations

Question 1. The three boxes in this diagram represent the three major biosynthetic pathways in aerobic respiration. Arrows represent net reactants or products.

Arrows numbered 4, 8, and 12 can all be :

1. ATP
2. H20
3. FAD+orFADH₂
4. NADH.

Answer: 4. NADH.

Question 2. Consider the following statements with respect to respiration.

1. Glycolysis occurs in the cytoplasm of the cell.
2. Aerobic respiration takes place within the mitochondria.
3. The electron transport system is present in the outer mitochondrial membrane.
4. C₅₁H₉₈C₆ is the chemical formula of Tripalmi- tin, a fatty acid.
5. Volume of O₂ evolved

Respiratory quotient = Volume of O₂ evolved \ Volume of CO₂ consumed

Of the above statements

1. 1, 2, and 4 alone are correct.
2. 2, 3, and 4 alone are correct.
3. 3, 4, and 5 alone are correct.
4. 2, 4, and 5 alone are correct.
5. 1, 3, and 5 alone are correct.

Answer: 1. 1, 2, and 4 alone are correct

Question 3. Anaerobic respiration of yeast produces :

1. Oxygen
2. Nitrogen
3. CO₂
4. H₂O.

Answer: 3. CO₂

Question 4. Metabolism of one palmitic acid yields ATP :

1. 36 ATP
2. 56 ATP
3. 136 ATP
4. 48 ATP.

Answer: 3. 136 ATP

Question 5. Alcoholic fermentation is carried out by :

1. Saccharomyces
2. Lactobacillus
3. Clostridium
4. Aspergillus.

Answer: 1. Saccharomyces

Respiration In Plants NEET Exam Preparation

Question 6. Cytochrome is :

1. Metallo flavoprotein
2. Fe containing porphyrin pigment
3. Glycoprotein
4. Lipid.

Answer: 2. Fe containing porphyrin pigment

Question 7. In the case of the Kerbs cycle, the pyruvic acid before being combined with oxaloacetic acid is converted to :

1. citric acid
2. isocitrate
3. succinyl CoA
4. acetyl CoA.

Answer: 4. acetyl CoA.

Question 8. Which of the following receives electrons at the end of ETC?

1. H₂O
2. H₂
3. CO₂
4. Cytochrome a3.

Answer: 4. Cytochrome a3.

Question 9. What is the total production of ATP at the end of a complete breakdown of one molecule of glucose during aerobic respiration?

1. 4
2. 8
3. 38
4. 34.

Answer: 3. 38

Question  10. Respiration in germinating seeds is usually high but with a decline in water and maturation the rate of respiration :

1. increases steadily
2. decreases steadily
3. remains constant
4. increases and decreases alternatively.

Answer: 2. decreases steadily

Question 11. PPP shunt is more advantageous than the Krebs cycle as :

1. it utilizes less oxygen
2. it reduces more of oxygen
3. it yields more ATP
4. ribose sugar is released which is used in the formation of nucleic acid.

Answer: 4. ribose sugar is released which is used in the formation of nucleic acid.

Question 12. The mechanism of aerobic respiration was discovered by :

1. Calvin
2. H. Krebs
3. Hatch and
4. Slack Pasteur.

Answer: 2. H. Krebs

Question 13. The dough kept overnight in a warm place becomes soft and spongy due to :

1. osmosis
2. absorption of CO₂
3. cohesion
4. fermentation.

Answer: 4. fermentation.

Respiration In Plants NEET Syllabus Topics

Question 14. In glycolysis, electrons are removed by :

1. ATP
2. NAD
3. Glyceraldehyde 3-phosphate
4. Molecular oxygen.

Answer: 2. NAD

Question 15. During which stage in the complete oxidation of glucose are the greatest number of ATP molecules formed from ADP?

1. Conversion of pyruvic acid to acetyl CoA
2. Electron transport chain
3. Glycolysis
4. Krebs cycle.

Answer: 4. Krebs cycle.

Question 16. The chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on :

1. Proton gradient
2. Membrane potential
3. Accumulation of Na ions
4. Accumulation of K ions.

Answer: 1. Proton gradient

Question 17. How many ATP molecules could maximally be generated from one molecule of glucose, if the complete oxidation of one mole of glucose to CO^–, and H₂O yields 686 kcal and the useful chemical energy available in the high energy phosphate bond of one mole of ATP is 12 kcal?

1. Fifty-seven
2. One
3. Two
4. Thirty.

Answer: 1. Fifty-seven

Question 18. Which of the following statements is/are not true?

A. one ATP molecule yields 32 kJ of energy

B. pentose phosphate pathway was discovered by Dickens

C. when tripalmitin is used as a substrate, the R.Q. is 0.7

D. energy released by one molecule of glucose on complete oxidation corresponds to 1292 kJ.

1. A, B, and D
2. only C and D only
3. A and D only
4. A, C, and D only.
5. C only.

Answer: 3. A, C, and D only.

Question 19. All enzymes of the TCA cycle are located in the mitochondrial matrix except one which is located in inner mitochondrial membranes in eukaryotes and the cytosol in prokaryotes. This enzyme is :

1. isocitrate dehydrogenase
2. malate dehydrogenase
3. succinate dehydrogenase
4. lactate dehydrogenase.

Answer: 3. succinate dehydrogenase

Question 20. The overall goal of glycolysis. Krebs cycle and the electron transport system is the formation of:

1. ATP in one large oxidation reaction
2. Sugars
3. Nucleic acids
4. ATP in small stepwise units.

Answer: 4. ATP in small stepwise units.

Respiration In Plants NEET Syllabus Topics

Question 21. Which one of the following mammalian cells is not capable of metabolizing glucose to carbon dioxide aerobically?

1. Unstriated muscle cells
2. Liver cells
3. Red blood cells
4. White blood cells.

Answer: 3. Red blood cells

Question 22. Which of the metabolites is common to the respiration-mediated breakdown of fats, carbohydrates, and proteins?

1. Frutosc 1,6- bisphosphate
2. Pyruvic acid
3. Acetyl CoA
4. Glucose – 6 – phosphate

Answer: 3. Acetyl CoA

Mineral Nutrition In Plants Multiple Choice Questions.

Question 1. Iron is mainly absorbed in :

1. Ferrous form
2. Ferric form
3. Combined form
4. All the above.

Answer:  4. Ferrous form

Question 2. Micronutrients are those elements :

1. Not important for plant growth
2. Required in large quantity
3. Required in small quantities and are important as macro-nutrients
4. Not present in the soil.

Answer: 3. Required in small quantities and are important as macro-nutrients

Question 3. Which of the following micronutrients can be absorbed by foliage?

1. Hydrogen
2. Potassium
3. Sodium
4. Zinc.

Answer: 2. Potassium

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 4. Which of the following elements are not absorbed from the soil?

1. Nitrogen
2. Iron
3. Boron
4. Carbon.

Answer: 4. Carbon.

Mineral Nutrition NEET Question 5. Which of the following is a component of chlorophyll?

1. Calcium
2. Sodium
3. Zinc
4. Magnesium.

Answer:  4. Magnesium.

Question 6. Bidirectional translocation of minerals takes place through :

1. Xylem
2. Phloem
3. Parenchyma
4. Cambium.

Answer: 1. Xylem

Question 7. The most abundant element in plants is :

1. Oxygen
2. Nitrogen
3. Carbon
4. Hydrogen.

Answer : 3. Carbon

Question 8. Minerals of soil are derived from :

1. Rocks
2. Clay
3. Carbon
4. Organisms.

Answer: 1. Rocks

Question 9. Trace elements are :

1. Required in very minute quantity
2. Radioactive
3. Those which draw other elements
4. First discovered in protoplasm.

Answer: 1.  Required in very minute quantity

Mineral Nutrition NEET  Question 10. Pre-mature leaf-fall is caused by to deficiency of :

1. Zinc
2. Cobalt
3. Nitrogen
4. Potassium.

Answer : 3. Nitrogen

Question 11. The chlorophyll is not formed without :

1. Potassium
2. Magnesium
3. Calcium
4. Phosphorus.

Answer: 2.  Magnesium

Question 12. The movement of mineral ions into plant root cells as a result of diffusion is called :

1. Endocytosis
2. Osmosis
3. Passive absorption
4. Active absorption.

Answer: 3. Passive absorption

Question 13. Woodward (1669) observed that plants grow better in muddy water than in rainwater because :

1. Muddy water had macronutrients dissolved in it
2. Muddy water had micronutrients dissolved in it
3. Muddy water had most of the essential elements dissolved in it
4. None of the above.

Answer: 3. Muddy water had most of the essential elements dissolved in it

Question 14. Who gave the criteria of essentiality?

1. R. Hill
2. F.F. Blackman
3. M.P. Kaushik
4. D.L. Arnon.

Answer: 4. D.L. Arnon.

Question 15. Which one of the following elements is essential for the photolysis of water?

1. Chlorine
2. Calcium
3. Sodium
4. Sulphur.

Answer: 1. Chlorine

Question 16. Which one of the following plants cannot fix atmospheric nitrogen directly?

1. Bean
2. Castor
3. Gram
4. Pea.

Answer: 2. Castor

Question 17. In the nitrogen cycle, nitrite is converted to nitrate by :

1. Azotobacter
2. Rhizobium
3. Nitrosowonas
4. Nitrobacter.

Answer: 4. Nitrobacter.

Mineral Nutrition NEET  Question 18. Plants absorb mineral salts from the soil solution through:

1. A semipermeable membrane into the cytoplasm by selective absorption
2. Perforations at the apex of root hair cells
3. The cell wall which is permeable
4. None of the above.

Answer: 1.  A semipermeable membrane into the cytoplasm by selective absorption

Question 19. Deficiency of iron causes :

1. Bending of leaf tip
2. Interveinal chlorosis first in young leaves
3. Decrease in protein synthesis
4. Reduced leaves and stunted growth.

Answer: 2. Interveinal chlorosis first in young leaves

Question 20. The function of Mg and Fe is:

1. Synthesis of chlorophyll
2. Synthesis of proteins
3. Synthesis of fat
4. Synthesis of organic acids.

Answer: 1. Synthesis of chlorophyll

Question 21. Which of the following elements is involved in nitrogen metabolism in the reduction of nitrates?

1. Zinc
2. Molybdenum
3. Boron
4. Manganese.

Answer: 2.  Molybdenum

Question 22. The mineral constituent of the cell wall is :

1. Iron
2. Sulphur
3. Potassium
4. Calcium.

Answer: 4.  Calcium.

Question 23. Active uptake of minerals by roots mainly depends on the :

1. Availability of oxygen Light
2. Temperature
3. Availability of carbon dioxide.

Answer: 1.  Availability of oxygen Light

Mineral Nutrition NEET  Question 24. Which of the following is a macronutrient?

1. Ca
2. Mn
3. Zn
4. Cu.

Answer: 1.  Ca

Question 25. Which of the following is a trace element?

1. Zn
2. Ca
3. P
4. Mg.

Answer: 1. Zn

Question 26. Synthesis of IAA requires:

1. Iron
2. Zinc
3. Calcium
4. Nitrogen.

Answer: 2. Zinc

Mineral Nutrition MCQ Question 27. Which of the following is common to ferredoxin and cytochrome? ,

1. Na
2. K
3. Fe
4. Mg.

Answer : 3. Fe

Question 28. The brown colour of the leaves of cabbage is due to the deficiency of:

1. Boron
2. Nitrogen
3. Sulphur
4. Calcium.

Answer: 1. Boron

Question 29. Most of the minerals in inorganic form are transported through :

1. xylem
2. Phloem
3. Cortex
4. Cambium.

Answer: 1. xylem

Mineral Nutrition MCQ Question 30. The mass flow hypothesis explains the transport of:

1. Water
2. Food materials
3. Salts
4. Auxins.

Answer:  2. Food materials

Question 31. Which of the following does not require carrier molecules during transport through cell membranes?

1. Na+ and K+ transport
2. Active transport of sugars and amino acids
3. Simple diffusion
4. Facilitated diffusion.

Answer: 3. Simple diffusion

Question 32. In a citrus plantation, all the plants were found to be suffering from the die-back disease and spraying of fungicides was of no help. This problem was due to the deficiency of:

1. Auxins
2. Zinc
3. Gibberellic acid
4. Copper.

Answer: 4. Copper.

Question 33. In fruit trees a disease exanthema is caused by the deficiency of:

1. Na
2. Ca
3. Cu
4. P

Answer: 3. Cu

Question 34. Active transport of molecules from outside to inside across a membrane requires:

1. Cyclic AMP
2. Acetylcholine
3. ATP (energy)
4. Choline.

Answer:  3. ATP (energy)

Question 35. If chlorophyll is burnt, what will be left?

1. Fe
2. Na
3. Mg
4. Mn.

Answer: 3.  Mg

Mineral Nutrition MCQ Question 36. Deficiency of molybdenum causes:

1. Poor development of vasculature
2. Bending of leaves
3. Chlorosis of leaves
4. Mottling or necrosis of leaves.

Answer: 4.  Mottling or necrosis of leaves

Question 37. Which one of the following elements plays an important role in biological nitrogen fixation?

1. Molybdenum
2. Manganese
3. Copper
4. Zinc.

Answer: 1. Molybdenum

Question 38. Photolysis of water is increased by :

1. Manganese
2. Zinc
3. Boron
4. Copper.

Answer: 1.  Manganese

Question 39. The role of inorganic nutrients in plant growth was at first indicated by :

1. Wood ward
2. Knop ‘
3. Stewart
4. De Saussure.

Answer: 2.  Knop ‘

Question 40. Which of the following essential mineral elements is not a constituent of any enzyme, but stimulates the reactions of many enzymes?

1. Potassium
2. Zinc
3. Manganese
4. Magnesium.

Answer: 1. Potassium

Question 41. The essential nutrient element required by plants in the least quantity is :

1. Chlorine
2. Zinc
3. Molybdenum
4. Manganese.

Answer: 3. Molybdenum

Biology MCQ Mineral Nutrition Question 42. Ammonium sulfate is a :

1. Enzyme
2. Fertilizer
3. Weed killer
4. Pesticide.

Answer: 2. Fertilizer

Question 43. For normal growth of plants one of the following is not required :

1. Magnesium
2. Lead
3. Potassium
4. Iron.

Answer: 2. Lead

Question 44. The essential element for the synthesis of auxin is :

1. Zn
2. Phosphorus
3. Sulphur
4. Potassium.

Answer: 1. Zn

Question 45. Pre-mature leaf-fail is caused due to the deficiency of :

1. Molybdenum
2. Sodium
3. Phosphorus
4. Sulphur.

Answer: 3. Phosphorus

Question 46. Which one of the following can fix atmospheric nitrogen directly?

1. Pea
2. Brassica
3. Castor
4. Petunia.

Answer: 1. Pea

Biology MCQ Mineral Nutrition Question 47. Mg and Fe are required by the plants for the :

1. Energy transfer is concerned with photosynthesis
2. Synthesis of chlorophyll pigments in leaves
3. Mechanism of stomatal opening and closing
4. Translocation of carbohydrates from the leaf to the stem.

Answer: 2. Synthesis of chlorophyll pigments in leaves

Question 48. The non-essential elements in the plant are:

1. Calcium
2. Barium
3. Iron
4. Magnesium.

Answer: 2.  Barium

Question 49. An example of an anaerobic nitrogen-fixing saprophytic bacterium is :

1. Azotobacter
2. Rhizobium
3. Clostridium
4. Pseudomonas.

Answer: 3.  Clostridium

Question 50. Organisms which fix free nitrogen in the soil are :

1. Green algae
2. Ferns
3. Blue-green algae
4. Mosses.

Answer: 3.  Blue-green algae

Biology MCQ Mineral Nutrition Question 51. Nodules with nitrogen-fixing bacteria are present in the roots of:

1. Cotton
2. Gram
3. Wheat
4. Maize.

Answer: 2.  Gram

Question 52. Members of the bean family are particularly important for the rotation of crops:

1. Because they add green manure
2. They add nitrates to the soil
3. They make the soil porous
4. They add calcium to the soil.

Answer: 2.  They add nitrates to the soil

Question 53. Nitrogen is an essential component of :

1. Fats
2. Carbohydrates
3. Proteins
4. Hormones.

Answer: 3. Proteins

Question 54. The most important element associated with proto-plasm and proteinaceous materials of plants is :

1. Oxygen
2. Nitrogen
3. Potassium
4. Sulphur.

Answer: 2. Nitrogen

Question 55. Which is a micronutrient?

1. Calcium
2. Zinc
3. Magnesium
4. Phosphorus.

Answer: 2.  Zinc

Question 56. Minerals are absorbed by roots mainly by :

1. Active absorption
2. Diffusion
3. Donnan equilibrium
4. Transfusion.

Answer: 1.  Active absorption

NEET Biology Mineral Nutrition In Plants Question 57. Which of the following elements can plants take directly from air?

1. Phosphorus
2. Nitrogen
3. Carbon
4. Calcium.

Answer: 3.  Carbon

Question 58. Chlorosis in plants occurs due to :

1. High sunlight intensity
2. Low light intensity
3. Yellow pigment
4. Deficiency of magnesium and iron in the soil.

Answer: 4.  Deficiency of magnesium and iron in the soil.

Question 59. Hydroponics is ;

1. The study of soil conservators
2. Culture of plants in water
3. The study of plant ecology
4. None of the above.

Answer:  2. Culture of plants in water

Question 60. Non-essential elements for the proper growth of the plant are:

1. Potassium
2. Calcium
3. Magnesium
4. Culture of plants in water

Answer: 1.  Potassium

Question 61. Nitrogen is usually absorbed by the plant in the form of:

1. Nitrogen peroxide
2. Free nitrogen
3. Nitrate
4. None of the above.

Answer: 3. Nitrate

Question 62. Insectivorous plants can grow well in a soil deficient in: _

1. Calcium
2. Magnesium
3. Nitrogen
4. Iron.

Answer: 3.  Nitrogen

Question 63. Without essential mineral nutrients leaves of many plants turn yellow because of:

1. Plasmolysis
2. Etiolation
3. chlorosis
4. None of the above.

Answer: 3. chlorosis

NEET Biology Mineral Nutrition In Plants Question 64. Which element is essential as an electron carrier?

1. Iron
2. Zinc
3. Potassium
4. Calcium.

Answer: 1.  Iron

Question 65. Enzyme-catalyzed reactions can be inhibited by :

1. Mg2++
2. Zn2++
3. Cu2++
4. Hg2++.

Answer: 4.  Hg2++.

Question 66. If a dried leaf is taken in a crucible and heated to 600°C, a grey-coloured powder is left behind. It is referred to as:

1. Dry weight
2. Plant ash
3. Wilting percentage
4. Protein content of the plant.

Answer: 2.  Plant ash

Question 67. In the nodules of roots in leguminous plants, we find :

1. N2 producing bacteria
2. Denitrifying bacteria
3. Fixing bacteria
4. Ammonifying bacteria.

Answer: 3.  Fixing bacteria

Question 68. Which of the following is an obligate stem parasite?

1. Cuscuta
2. Orobanche
3. Dalbergia sissoo
4. Monotropa.

Answer: 1. Cuscuta

Question 69. Which of the following is a partial root parasite?

1. Sanlalum album
2. Rafflesia
3. Monotropa
4. Mango,

Answer: 1.  Sanlalum album

Question 70. Pick up the saprophytic angiosperm :

1. Neottia
2. Agaricus
3. Eucalyptus
4. Cuscuta.

Answer: 1.  Neottia

NEET Biology Mineral Nutrition In Plants Question 71. Helotism is master and slave relationship found in :

1. Lichens
2. Mysmicophytes
3. Nepenthes
4. Cuscuta.

Answer: 1.  Lichens

Question 72. The insectivorous plant, Nepenthes is also known as:

1. Sundew plant
2. Ficus
3. Pitcher plant
4. Dischidia.

Answer: 3. Pitcher plant

Question 73. The traps of carnivorous plants contain :

1. Polysaccharides
2. Digestive enzymes
3. Phospholipids
4. Weedicidcs.

Answer: 2. Digestive enzyme

Question 74. Which of the following formulae describes nitrogen fixation?

1. N₂ +3H₂→ 2NH₃
2. 2NH⁺₄ +202 + 8e→ N2 + 4H₂0
3. 2NH3 →N₂+ 3H2 ‘
4. 2N₂+ glucose —> 2 Amino acids.

Answer: 1. N₂ +3H₂→ 2NH₃

Question 75. Mineral uptake by a terrestrial plant is limited by insufficient:

1. Blue light
2. Soil water
3. Apoplast
4. Phellogen.

Answer: 2.  Soil water

Question 76. Plants that have mutualistic relations with nitrogen¬fixing bacteria provide the bacteria with :

1. N2
2. Enzymes
3. Sugars
4. Nitrite.

Answer: 3.  Sugars

Question 77. The nodule in a plant root where nitrogen-fixing bacteria live forms from cells of the :

1. Epidermis.
2. Cortex.
3. Endodermis
4. Vascular cylinder.

Answer: 2.  Cortex.

Mineral Nutrition MCQ  Question 78. Plants, such as clover and beans, that have nitrogen-fixing bacteria in their roots are in which of the following families?

1. Orchidaceae
2. Asteraceae
3. Solanaceae
4. Leguminosae.

Answer: 2. Asteraceae

Question 79. Contact exchange of ions occurs:

1. Between root and soil particles
2. Root and soil solution
3. Cell and external solution
4. All the above.

Answer: 1.  Between root and soil particles

Question 80. Bacteria that fix nitrogen for such plants as clover and beans are in which of the following genera?

1. Denitrovibrio
2. Rhizobium
3. Pseudomonas
4. Nitrobacter.

Answer: 2.  Rhizobium

Question 81. Salt respiration is :

1. Excretion of salt through respiratory channels
2. Decrease in respiration during salt absorption
3. Additional respiration involved in salt absorption
4. Linking of ion movement with respiratory chain.

Answer: 3.  Additional respiration involved in salt absorption

Question 82. Which of the following plants will enrich the soil with nitrogen?

1. Corn
2. Alfalfa
3. Wheatgrass
4. Beets.

Answer: 2.  Alfalfa

Question 83. Organisms that fix nitrogen in aquatic habitats are :

1. Green algae
2. Cyanobacteria
3. Crown algae

Protozoa.

Answer: 2.  Cyanobacteria

Question 84. ‘Grey-Speck’ disease is caused by the deficiency of:

1. Molybdenum
2. Zinc
3. Manganese
4. Boron.

Answer: 3.  Manganese

Mineral Nutrition MCQ  Question 85. The need of individual plants for any particular element is normally defined in terms of:

1. Critical period
2. Critical condition
3. Critical concentration
4. None of the above.

Answer:  3.  Critical concentration

Question 86. Permeability of protoplasm is accelerated by :

1. Na
2. K
3. Ca
4. P.

Answer: 2. K

Question 87. Black necrosis of the stem and root tip is caused by the deficiency of:

1. Magnesium
2. Chlorine
3. Copper
4. Boron.

Answer: 4. Boron.

Question 88. Which of the following is not caused by a deficiency of mineral nutrition?

1. Necrosis
2. Etiolation
3. Chlorosis
4. Shortening of internodes.

Answer:  Etiolation

Mineral Nutrition MCQ  Question 89. Which of the following is not essential for plant growth?

1. Zn
2. I,
3. K
4. Fe.

Answer: 2.  I

Question 90. Which of the following nutrient elements is most important for protein synthesis?

1. N,
2. K
3. Mg
4. Fe.

Answer: 1. N

Question 91. Which of die following is not a major element?

1. Zn
2. Ca
3. Mg
4. P.

Answer: 1. Zn

Question 92. Nitrogen fixation by bacteria requires the enzyme :

1. Decarboxylase
2. Nitrogenase
3. Nitrogen deaminase
4. Nitrodioxidase.

Answer: 2. Nitrogenase

Question 93. Zinc is essential for:

1. Biosynthesis of chlorophylls
2. Biosynthesis of 3—IA A
3. Stomatal closing
4. Oxidation of carbohydrates.

Answer: 2.  Biosynthesis of 3—IA A

Question 94. Plants that have naturalistic relations with nitrogen¬fixing bacteria receive from the bacteria :

1. Ammonium
2. Amino acids
3. Nitrate
4. Nitrite.

Answer:  1. Ammonium

Mineral Nutrition MCQ  Question 95. An association between a fungus and a root of a higher plant is termed mycorrhiza which is an example of:

1. Parasitism
2. Helotism
3. Symbiosis
4. Myrmecophily.

Answer: 3.  Symbiosis

Question 96. Which of the following groups of plants can grow in nitrogen-deficient soils?

1. Lichens
2. Gymnosperms
3. Bryophytes
4. Insectivorous plants.

Answer: 4. Insectivorous plants.

Question 97. The theory which suggests that C02 produced in respiration plays an important role in mineral absorption is:

1. Contact exchange theory
2. Carbonic acid exchange theory
3. Active absorption dietary
4. None of the above.

Answer: 2.  Carbonic acid exchange theory

Question 98. Nodulation of legumes is reduced in deficiency of:

1. Sulphur and potassium
2. Sulphur and boron
3. Manganese and copper
4. Zinc and iron.

Answer: 2. Sulphur and boron

Question 99. Presence of phosphorus:

1. Brings about healthy root growth
2. Promotes fruit ripening
3. Retards protein formation

None.

Answer: 3. Retards protein formation

Biology MCQ Mineral Nutrition Question 100. A balancing element is :

1. Ca
2. Mg
3. K
4. All the above.

Answer: 4. All the above.

Question 101. Match List I ( nutrient) with List II (deficiency symp¬tom in leaf) and select the correct answer using the codes given below the lists:

Answer: 2.

Question 102. The soluble resources of phosphorus and nitrogen in soil generally get depleted because they are usually found as:

1. A disproportionate mixture of negatively and positively charged ions
2. Negatively charged ions
3. Only positively charged ions
4. A balanced mixture of negatively and positively charged ions.

Answer: 2.  Negatively charged ions

Question 103. At times of heavy rain, minerals in the upper layers of the soil are moved downward by a process known as:

1. Smearing
2. Leaching
3. Weathering
4. Gravitation.

Answer: 2. Leaching

NEET Biology Mineral Nutrition In Plants

The mineral elements that are essential for the plant body are mostly absorbed by roots. Only Carbon, Oxygen and Hydrogen are obtained from air and water. The utilization of various elements absorbed by plants in growth and development is called mineral nutrition.

NEET Biology Mineral Nutrition In Plants Essentiality Of An Element

The essentiality of an element can be judged by ash analysis, solution culture or solid medium culture. The earliest culture solution was prepared by Sachs.

NEET Biology Mineral Nutrition In Plants Functions Of Minerals

The minerals perform several functions such as the construction of the plant body, maintenance of osmotic pressure, permeability, pH, performing catalytic function, imparting toxicity and balancing function.

NEET Biology Mineral Nutrition In Plants Physiological Role of Essential Elements

• Each important element executes a unique array of functions that are not entirely replicated by other essential elements.
• An element is crucial for the survival of a higher green plant for one or more of the following four reasons.
• It may provide a nutritive function as a constituent of one or more primary classes of plant compounds.
• It may also play a catalytic role, either as an enzyme activator or as an essential component of an enzyme.
• It may operate as three non-catalytic ‘metallo-biomolecules’ or as a free ion.

Macro-elements. A scientific approach to the role of mineral elements started with Sachs and Knop in 1850. It has been proved that carbon, hydrogen, oxygen, sulfur, phosphorus, calcium, magnesium, and iron are essential for the growth and development of plants.

Read and Learn More NEET Biology Notes

These elements are required in large amounts and without them normal metabolism is retarded. These elements are referred to as Macro-elements or Major elements because of the relatively large quantities in which they are needed for plant life.

Essential Mineral Elements In Plants NEET Notes

Micro-elements. Plants also require other elements in small quantities. These elements are not involved in the composition of plants but are present in traces. They help as catalysts in various metabolic processes.

These elements which are required in small quantities or traces are called micro-elements or trace elements. Some important micro-nutrients are Manganese, Zinc, Boron, Copper Molybdenum and Chlorine.

NEET Biology Mineral Nutrition In Plants Minerals Critical Concentration

1. The need of individual plants for any particular element is normally defined in terms of -critical concentration. This is the concentration of that nutrient, measured in the tissue, 1st below the level which gives maximum growth (Epstein, 1972).
2. In the absence of any essential element, the plant will be expected to exhibit certain morphological and biochemical symptoms of that deficiency. In some cases, the deficiency symptoms will clearly reflect the functional role of that element (Hopkins, 1995)

NEET Biology Mineral Nutrition In Plants Minerals Other Elements

1. Sodium. The importance of sodium for the growth of marine algae was first realised by Osterhout in 1906. It is also needed by blue-green algae for growth. In higher plants, it maintains the differential permeability of cytomembranes.
2. It also participates in nitrogen metabolism. The C₄  plants also require sodium. It may partially substitute for potassium in lower as well as higher plants.
3. Silicon. It is present in grasses, sedges, rushes, equisetum, and several algal forms. Somnar, 1926 observed that it is essential for the growth of rice and millet whereas Lipman, 1938 discovered that it is necessary for the growth of sunflower and barley.
4. Aluminium. It is found to improve the growth of several plants. On the other hand, many plants are known to possess sensitivity to aluminium toxicity.
5. Cobalt. It is a component of vitamin B₁₂  (Cyanocobalamin). A few blue-green algae and the bacterium Rbizobium, a symbiotic nitrogen-fixing bacteria of leguminous nodules also require cobalt
6. Gallium. Steinberg, 1945-46 found that the fungus Aspergillus niger and Lenina minor need gallium for their growth.
7. Selenium. Plants like Astragalus and Stanleya act as selenium indicators. They contain a high concentration of selenium.
8. Iodine. Some marine algae like Laminaria accumulate iodine in huge amounts.
9. Besides, gold is known to occur in Equisetum and vanadium is necessary for the growth of certain plants.

NEET Biology Mineral Nutrition In Plants Mineral Uptake By Plants

A plant obtains C₂ H₂ and O₂ as CO₇ are obtained from the atmosphere and water and the rest of the minerals are taken from the soil (solution mining). The absorption may occur through root hair Mycorrhizae or the mature part of the root.

• The soils may be acidic having principal cation H⁺, or alkaline where Ca₄-1″ predominates. Acidic soils are made alkaline by liming (cation exchange) and alkaline soil by adding sulphur becomes acidic.
• This sulphur is oxidised to sulphuric acid by microbes.
• The cell-to-cell movement of ions occurs through symplast and plasmodesmata. There may be pores of 7 A diameter in the plasma membrane. Besides, there are carrier proteins (permeases) in this membrane.
• Dead membranes are more permeable than living. The membranes are more permeable to O_7, N₂ COT and other smaller molecules. The lipophilic molecules are more permeable than hydrophilic.
• The ionic absorption has been regarded as an active process or passive. In the latter process, there is no expenditure of metabolic energy,
• According to Hylmo, there is a mass flow of mineral ions into the root along with transpiration current. Many other workers believe that the mineral ions diffuse into the root along a concentration gradient.
• The part of the plant cell or tissue that permits free diffusion is called outer space and the apparent volume accommodating these ions is apparent free space.
• The facilitated diffusion occurs through protein channels. It is stereospecific and occurs up to the saturation limit. The ions are transported through carrier proteins,
• The ion exchange hypothesis states that a particular ion is exchanged by a similar type of ion i.e., a cation by a cation and anion by an anion. It may occur by contact exchange or by the formation of carbonic acid.
• The Donnan equilibrium is believed to be reached due to the presence of some diffusible or fixed zones. It explains the entry of ions against a concentration gradient,
• There is ample evidence to believe in the active uptake of salts such as a faster rate of absorption, absorption against a concentration gradient, the correlation between rates of respiration and salt absorption, salt-induced respiration etc.
• According to Van den Honert, the cation and anions are transported through separate carriers. They make a complex and release them into the cell enzymatically,
• Lundegardh believes that the anions are transported across the membrane through a cytochrome pump whereas the cations are transported passively,
• Many people think that in the transport of ions, ATP is used up. The hydrolysis of ATP causes the release of energy. The transport is mediated by ATP ase.
• The movement of ions and carriers may occur in the same direction (symport carrier) or the opposite direction ( antiport carrier).
• While Goldacre believes that contractile proteins act as carriers. IJennett-CJark considers that lecithin is the main carrier of ions across the membrane.
• The process of salt absorption is influenced by many factors such as temperature, light, oxygen, and growth. pH and mineral interaction.

Role Of Macronutrients In Plant Growth NEET

NEET Biology Mineral Nutrition In Plants Deficiency Symptoms Due To Mineral Deficiencies

1. Chlorosis: Chlorophyll formation in leaf tissue is impaired due to mineral shortage or illness. It is sometimes referred to as a physiological disease, arising from deficiencies in certain minerals such as iron, magnesium, and nitrogen.
2. Etiolation: Etiolation refers to the yellowing or whitening of green plant tissues. Etiolation is a physiological occurrence observed in green plants cultivated in the absence of light.
3. Necrosis: Cellular and tissue necrosis.
4. Impeded development: Plants do not achieve normal height and stay stunted.
5. Abscission: Leaves, flowers, and fruit exhibit premature abscission in the fall.
6. Mottling: Presence of verdant and non-verdant regions.
7. Leaf Deformations: Abnormal leaf curling resulting from uneven growth is termed helotism. Heart rot in plants refers to the internal weakening or decomposition of tissues due to their breakdown.

NEET Biology Mineral Nutrition In Plants Special Modes Of Nutrition

1. The plants which are dependent on sonic other sources for their nutritional requirements are called heterotrophic plants which can be placed into four groups depending upon the sources of food: Parasites, saprophytes, symbionts and insectivorous or carnivorous plants.
2. Parasites are common among fungi and bacteria but less common among flowering plants. The angiospermic parasites are of two types: Partial parasites and total parasites or holopurnsites.
3. The partial parasites are green and thus photosynthesize but they obtain water and minerals from their host through their haustoria which remain in contact only with the xylem of the host. 1 he partial parasites are of two types i.e.
4. Partial stem parasites For example. Viscum (mistletoe), Loranthus and Arceuthobium. Arccuthobium minutissimum is the smallest green leafless parasite growing on Pinus excelsa. This plant is the minutest one among the dicots;
5. Partial root parasites For example. Sanlalum album (sandalwood tree) and Tliesitim.
6. The total parasites are non-green as they do not possess chlorophyll and hence derive their entire food from their host. Their haustoria communicates with both the xylem and phloem of the host.
7. Saprophytes obtain their food from dead and decaying organic matter and are common among fungi and bacteria but less common among higher plants. The saprophytic flowering plants are Neottia (bird’s nest orchid), Monotropa (Indian pipe), Corallorhiza, Epipogon, etc.
8. Almost all the saprophytic angiosperms possess mycorrhiza (an association of the fungus with the roots) and lack root hairs. Mycorrhiza may be ectotrophic as in Pinus, Belula, Monotropa (the Indian pipe), and Sarcodes; or endotrophic as in Neottia, Epipogon and Corallorhiza.
9. Symbionts form symbiotic associations in which both the organisms of the association are benefited Example. lichens, and the association of legumes with Rhizobium (N₂-fixing bacteria).
10. Insectivorous plants are autotrophic so far as their carbohydrate nutrition is concerned but they are dependent on captured insects for their nitrogen requirement as they grow in N₂-deficient soils (generally swamps and bogs). Thus, they are partly autotrophic and partly heterotrophic.
11. About 200 species of angiosperms are insectivorous and some of them are :
12. Drosera or Sundew – Its leaves possess glandular hairs called tentacles which secrete a sticky fluid containing digestive enzymes.
13. Utricularia or bladderwort is an aquatic, free-floating, rootless plant with dissected leaves and some of the leaf lobes are modified into sac-like structures called bladders.
14. Nitrogen And Nitrogen Metabolism.

• Nitrogen is a highly inert gas. Most of the nitrogen exists in proteins and amino acids. However, it is also found in large quantities in nucleic acids, cytochromes, chlorophyll, vitamins, alkaloids etc.
• It is not used directly and is found in fixed forms in combination with C₂ H₂O₂ to constitute other compounds. Nitrogen plays an important role in metabolism, heredity, reproduction and growth. Nitrogen combines with oxygen and hydrogen to form nitrate (NO₂), nitrite (NO₂) and ammonium salts (NH₂). Bacteria and blue-green algae can also fix atmospheric nitrogen.

• Soil contains nitrogen in the form of nitrate, ammonium salts and organic nitrogenous compounds. Ammonia is absorbed by the plants directly. Urea and amino acids can be absorbed directly by the plants. Urea is first converted into ammonia by the action of the enzyme urease.

Important Contributors

• Sachs, using a culture solution showed the essentiality of nitrogen for plant growth.
• Jenny and Overstreet (1938) proposed ion-exchange theory.
• Bulk flow or mass flow theory was given by Hylmo (1953) and later sup¬ported by Kramer (1956).
• The study of mineral nutrition was carried out by Knop (1865).
• Winogradsky (1891) discovered biological nitrogen
• P.R. Stout and D.R. Hoagland proved that minerals transport are translocated in the plants through the xylem.
• Aristotle (300 B.C.) thought that plants get their nutrients in organic form from the soil.
• Theodore de Saussure (1804) proposed that nutrients are made available to the plants from soil.
• T.H. Vanden-Honert (1936) proposed carrier-mediated uptake of ions.
• Jenny and Overstreet (1938) proposed ion-exchange theory.
• Goerick (1940) developed Hydroponics.
• Lundegardh (1950) proposed the cytochrome pump theory of salt absorption.
• Hylmo (1953) proposed mass flow theory.
• Bennet Clark (1956) proposed protein-lecithin as a carrier.
• The enzyme nitrogenase successively reduces N2 into diimide and hydrazine and finally to 2NH with the utilisation of ATP.

1. NHN NH = NH→NHT – NHT→2NH₄ 
2. Nitrogen Diimide Hydrazine Ammonium
3. Hydrogen ions and electrons for the reduction process are provided by reduced ferredoxin.
4. Nitrogenase acts only in anaerobic conditions and under aerobic conditions it undergoes irreversible damage.
5. The enzyme nitrogenase requires ATP, Mg⁺⁺, an electron source and anaerobic conditions for converting nitrogen to ammonia.
6. Anaerobic condition in symbiotic nitrogen fixation is provided by leghaemoglobin present in root nodules.
7. Haemoglobin is made up of four peptide chains while leghaemoglobin in root nodules is a single peptide chain.
8. Leghaemoglobins are red colour haemoglobin-like pigments which absorb oxygen and protect enzymes from oxygen.
9. Though nitrogen is present in abundance in the atmosphere but cannot be directly used. It is converted into nitrates and nitrites by certain nitrogen-fixing bacteria and cyanobacteria.
10. Species of Rhizobium are associated symbiotically with nodules of nodulated tap roots of leguminous plants.

• The di-nitrogen (N,) of the atmosphere is reduced to ammonia by the action of the enzyme nitrogenase in the presence of a reducing agent and energy currency ATP.
• Nitrogen Fixation Requires Three Components.
• Strong reducing agent
• ATP to transfer hydrogen atoms to dinitrogen ami the (f/x) enzyme sj-stem.
• The reducing agents (FAD) and ATP are provided by photosynthesis and respiration.
• Ammonia is utilized by plants as nitrate which is absorbed with the help of enzymes nitrate reductase and nitrite reductase.
• Ammonium ions are used for the synthesis of amino acids, proteins and other nitrog¬enous molecules of plants.
• Reductive animation. It is the primary pathway of amino acid formation. It involves the incorporation of ammonia or ammonium ions into ketoglutaric acid to yield glutamic acid.
  n-ketoglutaric acid + NH, -MX-Iminoglutaric acid a-Iminoglutaric acid + NADH + H⁺ Glutamic acid + NAD
• Transamination. It involves tyre transfer of the amino group (-NH,) of one amino acid to the carboxylic group of a keto acid. As far as 17 different amino acids can be synthesized from glutamic acid by transamination.
• Eight protons and six electrons are required to reduce a molecule of nitrogen into two molecules of ammonium.

Micronutrient Deficiencies In Plants NEET Study Material

Hydrogen is used in the conversion of molecular nitrogen to ammonia.

NEET Biology Mineral Nutrition In Plants Minerals

• The chemical substances that provide nourishment to living organisms are termed nutrients,
• Mostly all plants obtain their inorganic nutrients from soil, water and atmosphere.
• Some green plants supplement their nutritional requirements with parasitic and insectivorous habits, Out of 105 elements, plants require about 20 elements. <=S> Inorganic elements are essential for their normal growth and reproduction.
• Some elements form structural components whereas others participate in metabolic reactions or act as cofactors for several enzymes.
• Elements become essential constituents of proteins, carbohydrates, fats, nucleic acids etc. co Some of them serve as activators/cofactors for various enzymes.
• Heterotrophic plants could be parasitic, saprophytic, symbionts and insectivorous.
• Lichens, mycorrhizae etc. are examples of symbionts. CO Droserci, Utricularia and Nepenthes are examples of insectivorous plants.
• The carbon of plants is derived from that of atmospheric carbon dioxide.
• Deficiency of minerals results in disorders such as reduction in growth, chlorosis and necrosis, co The elements are absorbed through the root by active or pas¬sive absorption and transported through the xylem to other parts of the plant.
• Plants absorb minerals in the form of ions from the soil, Absorption of minerals occurs mainly from the region of elongation in the root.
• Outer space or apoplast includes cell walls and intercellular spaces.
• Inner space or symplast is formed by protoplast and plasmodesmata.
• Mineral ions enter into the apoplast by a passive process named diffusion.

The movement of ions from apoplast to symplast is by

1. Passive absorption
2. Active absorption

These are 

1. Passive ion absorption:

• Passive ion absorption transpires along the concentration gradient without the expenditure of energy (ATP).
• Theories explaining the passive absorption of minerals include
  1. Donnan equilibrium
  2. Ion exchange
  3. Mass flow hypothesis.
• According to the Don equilibrium concept (proposed by Donnan 1911) fixed ions present on the inner surface of the plasma membrane disturb the ionic equilibrium (electrochemical) of the cell. Initially, the cell accumulates cations when fixed ions are present, followed by the diffusion of anions into the cell.
• The ion exchange theory posited by Jenny and Overstreet involves the exchange of ions from root I P₂ OH with soil ions, facilitated by carbonic acid generated from the dissolution of CO₂ in water, which dissociates to produce fP and HCO₂ions for the ion exchange process.
• The movement of ions accompanying the movement of water owing to transpiration is termed mass low.

Active absorption:

The process of actively absorbing ions against their concentration gradient by utilizing energy is termed active absorption. Vandcn presented a carrier notion to elucidate active absorption.

NEET Biology Mineral Nutrition In Plants Quanta To Memory

• The roots of plants absorb a large number of elements from the soil. But only a few of these are essential for plant life.
• Sodium and Iodine which are essential for animals, are not required by most plants.
• Micronutrients are as important as macronutrients in plant nutrition.
• Among the micronutrients. Iron is required in much larger quantities.
• Recent research has shown that in addition to the already established microelements, Cobalt, Vanadium, Silicon, and Nickel may be essential for certain plants.
• Examples of electrophilic mycorrhiza are beech and oak.
• An example of endotrophic mycorrhiza which shows fungus within the roots is Epigonon.
• Loranthus and Viscum album are partial parasites.
• Cusciita reflex is a total stem parasite
• A few members of the family Orobanchaceae such as Orobanchc are total root parasites flourishing on the roots of tomato, potato, and brinjal.
• Epigonon (orchids), Monotropa, and sarcodes are a few examples of saprophyte plants.
• Excess of salts in soils leads to the development of plant indicators.
• The most common free ion in the cells is K⁺.
• Potassium is required for the activity of about 40 enzymes.
• Interveinal chlorosis of young leaves is due to deficiency of Iron, while that in old leaves is due to deficiency of Mg.
• Deficiency of Zn causes little leaf disease in cereals.
• The plants growing in water or by solution culture technique are termed hydroponics or soilless culture.
• Manganese is essential for the photolysis of water.
• Prokaryotes absorb the element nitrogen in gaseous form.
• Gold has been reported to occur in the stems of Equisetum
• Na-EDTA is the disodium salt of ethylene diamine tetra acetic acid.
• In plants growing in nitrogen-deficient soils, the older leaves become chlorotic first, because nitrogen from older leaves moves into younger leaves. Younger leaves show normal nitrogen as they receive it from older leaves.
• The pungent smell of onion and garlic is due to sulphur compounds.
• NPK are the critical elements.
• NPK fertilizers contain nitrophosphate with potassium.
• Nitrogen is translocated from roots as amides, amines and amino acids through the xylem. Phloem sap contains P-proteins as well as citrates and malates. The concentration of Ca⁺⁺ in phloem sap is lower than in xylem.
• The young leaves collect phosphorus and older leaves have calcium deposition. Iron is deposited along the veins and cobalt is in the hydathodes.
  Aeroponics is a system for growing plants with their roots bathed in the nutrient mist (a cloud of moisture in the air).

Symptoms Of Mineral Deficiency In Plants NEET Biology

NEET Biology Mineral Nutrition In Plants Questions From Competitive Examinations

Question 1. Inorganic nutrients are present in the soil as :

1. Biomolecules
2. Atoms
3. Electrically charged ions
4. Colloids.

Answer: 3. Electrically charged ions

Question 2. Clay and organic matter in the soil have negative charges. They attract positively charged ions like :

1. Ca²⁺
2. Mg²⁺
3. K⁺
4. All the above.

Answer: 4.  All the above.

Question 3. Which of the following is required by plants for the formation of ATP’?

1. N, Ca
2. N, Cu
3. N, K
4. N. Ca.

Answer: 1.  N, Ca

Question 4. Magnesium is an important component of:

1. Chlorophyll
2. Florigen
3. Hacmoerythrin
4. Enzyme.

Answer: 1.  Chlorophyll

Question 5. Plants use Zinc as :

1. Zn
2. Zn_2⁺
3. ZnSO₄
4. Zn(NO₃)₂.

Answer: 2. Zn_2⁺

Question 6.’ Plants growing in urea sprayed but Mg deficient soil
will show:

1. Deep green foliage
2. Early flowering
3. Yellowing of leaves
4. Loss of pigmentation in petals.

Answer: 3. Yellowing of leaves

Question 7. ATP molecules combine with carrier molecules and allow passage of substances :

1. No ATP is required
2. Along concentration gradient
3. Against concentration gradient
4. Both (2) & (3).

Answer: 3. Against concentration gradient

Question 8. Enzyme first used for nitrogen fixation :

1. Nitrogenase
2. Nitroreductase
3. Transferase
4. Transaminase.

Answer: 1. Nitrogenase

Question 9. This is an insectivorous plant:

1. Eichhornia
2. Opuntia
3. Crotolariadarsa
4. Utricularia.

Answer: 4. Utricularia.

Symptoms Of Mineral Deficiency In Plants NEET Biology

Question 10. Which of the following is non-symbiotic?

1. Azotobacter
2. Nostoc
3. Rliizobiwn
4. None of the above.

Answer: 1. Azotobacter

Question 11. Trace elements in plants are:

1. K
2. P
3. Zn
4. S.

Answer: 3. Zn

Question 12. Which of the following elements is essential for nitrogen metabolism in plants?

1. Iron
2. Potassium
3. Magnesium
4. Molybdenum.

Answer: 4. Molybdenum

Question 13. Plants absorb nitrogen in the form of:

1. Nitrate
2. Nitrites
3. Urea and NH₃
4. NH₄.

Answer: 1. Nitrate

Question 14. Which element is located at the centre of the porphyrin ring in chlorophyll?

1. Manganese
2. Calcium
3. Magnesium
4. Potassium.

Answer: 3. Magnesium

Question 15. The major role of minor elements inside living organisms is to act as:

1. Binder of cell structure
2. Co-factors of enzymes
3. Building blocks of important amino acids
4. Constituent of hormones.

Answer: 2. Co-factors of enzymes

Question 16. Plants deficient in the element zinc, show its effect on the biosynthesis of plant growth hormones:

1. Abscisic acid
2. Auxin
3. Cytokinin
4. Ethylene.

Answer: 2. Auxin

Question 17. The most abundant element found in plants is :

1. Carbon
2. Nitrogen
3. Iron
4. Manganese.

Answer: 1. Carbon

Question 18. The movement of ions is usually called llux. The inward movement into cells is called :

1. Efflux as an active process
2. Influx as a passive process
3. Influx as an active process
4. Efflux as a passive process

Answer: 3. Influx as an active process

Symptoms Of Mineral Deficiency In Plants NEET Biology

Question 19. Molybdenum is obtained by plants and is a part of enzymes

1. P – MO            Q – Nitrogenase
2. P – MqO⁺²₂    Q – All enzymes
3. P – M_q              Q – Nitrate reductase
4. P – MqO⁺²₂    Q – Nitrogenase

Answer: 4. P – MqO⁺²₂    Q – Nitrogenase

Question 20. Which of the following is incorrect :

1. Potassium plays an important role in the opening and closing of stomata.
2. Some essential elements cannot alter the osmotic potential of a cell
3. C, H, 0 and N are structural elements of the cell.
4. In addition to 17 elements, there are some beneficial elements such as sodium, silicon, cobalt and sodium

Answer: 2.  Some essential elements cannot alter the osmotic potential of a cell

Question 21. Copper is the activator in enzymes:

1. Carbonic anhydrase
2. Tyrosinase
3. Lactic dehydrogenase
4. Tryptophanase.

Answer: 2. Tyrosinase

Question 22. If by radiation all the nitrogenase enzymes are inactivated, then there will be no :

1. Conversion of nitrate to nitrite
2. Fixation of atmospheric nitrogen
3. Fixation of nitrogen in legumes
4. Conversion of ammonium to nitrate.

Answer: 3. Fixation of nitrogen in legumes

Question 23. The ability of the Venus Flytrap to capture insects is due to :

1. A passive process requiring no special ability on the part of the plant
2. Chemical stimulation by the prey
3. specialized “muscle-like” cells
4. Rapid turgor pressure changes.

Answer: 4. Rapid turgor pressure changes.

Question 24. All of the following statements concerning the actinomycetous filamentous soil bacterium Frankia are correct EXCEPT that Frankia :

1. Can induce root nodules on many plant species
2. Cannot fix nitrogen in the free-living state
3. Forms specialized vesicles in which the nitrogenase is protected from oxygen by a chemical barrier involving triterpene hopanoids
4. Like Rhizobium, it usually Infects its host plant through root hair deformation and stimulates cell proliferation in the host’s cortex.

Answer: 2. Cannot fix nitrogen in the free-living state

Question 25. If there is a deficiency of micronutrients that not only affects the growth of plants but also vital functions such as photosynthetic and mitochondrial electron flow. Among the list given below, which group of three elements shall affect most, both photosynthetic and mitochondrial electron transport :

1. Cu, Mn, Fe
2. Ca, K, Na
3. Mn, Co.
4. Co, Ni, Mo

Answer: 1. Cu, Mn, Fe

Question 26. Prolonged liberal irrigation of agricultural fields is likely to create the problem of:

1. Acidity
2. Aridity
3. Salinity
4. Metal toxicity.

Answer: 3. Salinity

Question 27. The first stable product of fixation of atmospheric nitrogen in leguminous plants is:

1. Ammonia
2. NO₃
3. Glutamate
4. NO₂

Answer: 1. Ammonia

Question 28. Which is essential for root hair growth?

1. Ca
2. Zn
3. MO
4. S.

Answer: 1. Ca

Mechanisms Of Mineral Uptake In Plants NEET Exam

Question 29. Sulphur is an important nutrient for optimum growth and productivity in :

1. Fibre crops
2. Oilseed crops
3. Pulse crops
4. Cereals.

Answer: 3. Pulse crops

Question 30. Nitrogen fixation in root nodules of legumes is to :

1. Convert atmospheric N₂ to NH₃
2. Convert ammonia to nitrite
3. Transport oxygen for the activity of nitrogenase
4. Protect nitrogenase from oxygen.

Answer: 4. Protect nitrogenase from oxygen.

Question 31. Match the following and choose the correct combination from the options given.

1. A-2 ,   B-l,   C-4,   D-3
2. A -4,  B- 2,  C-3,  D-4
3. A-4,   B-3,   C-2,   D- 1
4. A-1,   B-3,  C-4,    D-2
5. A-3,   B -4,  C-1,  D-2.

Answer: 1. A-2 ,B-l ,C-4 ,D-3

Question 32. A plant requires magnesium for :

1. Protein synthesis
2. Chlorophyll synthesis
3. Cell wall development
4. Holding cells together.

Answer: 2. Chlorophyll synthesis

Question 33. Which one of the following elements is not an essential micronutrient for plant growth?

1. Zn
2. Cl
3. Ca
4. Mn.

Answer: 3. Ca

Question 34. Match the following mineral elements with their deficiency symptom and choose the correct option.

1. A-3,  B-1,  C-5,  D-2,  E-4
2. A-1,  B-4,  C-5,  D-3,  E-2
3. A-3,  B-4,  C-5,  D-1,  E-2
4. A-2,  B-3,  C-4,  D-1,  E-5
5. A-4,  B-2,  C-1,  D-3,  E-5

Answer: 3.

Question 35. Which one of the following elements in plants is not remobilised?

1. Phosphorus
2. Calcium
3. Potassium
4. Sulphur.

Answer: 2. Calcium

Question 36. Nitrifying bacteria :

1. Oxidize ammonia to nitrates
2. Convert free nitrogen to nitrogen compounds
3. Convert proteins into ammonia
4. Reduce nitrates to free nitrogen.

Answer: 1.  Oxidize ammonia to nitrates

Question 37. The function of leghaemoglobin in the root nodules of legumes is:

1. Inhibition of nitrogenase activity
2. Oxygen removal
3. Nodule differentiation
4. Expression of if gene.

Answer: 2. Oxygen removal

Question 38. Which one of the following is the wrong statement?

1. Root nodule-forming nitrogen fixers live as aerobes under free-living conditions.
2. Phosphorus is a constituent of cell membranes, certain nucleic acids and all proteins.
3. Nitrosomonas and Nitrobacter are chemoautotrophs
4. Anabaena and Nostoc are capable of fixing nitrogen in a free-living state also.

Answer: 2.  Phosphorus is a constituent of cell membranes, certain nucleic acids and all proteins.

Question 39. Consider the following statements concerning facilitated transport.

1. Requires ATP energy,
2. Transport saturates
3. Highly selective.
4. Requires special membrane properties.
5. Uphill transport.

Of The Above Statements

1. 1, 2 and 3 are relevant but 4 and 5 are irrelevant
2. 2, 3 and 5 are relevant but 1 and 4 are irrelevant
3. 3, 4 and 5 are relevant but 1 and 2 are irrelevant
4. 1, 4 and 5 are relevant but 2 and 3 are irrelevant
5. 2, 3 and 4 are relevant but 1 and 5 are irrelevant.

Answer:  3. 3, 4 and 5 are relevant but 1 and 2 are irrelevant

Question 40. Find out the Correctly matched pair.

Answer. 4. Manganese – Needed in the splitting of water to liberate oxygen during photosynthesis.

NEET Biology Photosynthesis And Translocation Of Organic Solutes Multiple Choice Questions

Question 1. The oxygen from H->0 is incorporated into :

1. Oxygen gas
2. Water
3. Carbohydrates
4. NADPH + H+.

Answer: 1. Oxygen gas

Question 2. Engelmatin’s experiment with Spirogyra demonstrated that :

1. The full spectrum of sunlight is needed for photosynthesis
2. Only red wavelengths are effective in causing photosynthesis
3. Only blue wavelengths are effective
4. Both blue and red wavelengths are effective.

Answer: 4. Both blue and red wavelengths are effective.

Question 3. Red and blue light support the highest rates of synthesis because :

1. These are the only wavelengths reaching from the sun
2. These are the only wavelengths that cannot be absorbed
3. Chlorophyll absorbs these wavelengths more than other wavelengths
4. These wavelengths have the highest energy visible spectrum.

Answer: 3. Chlorophyll absorbs these wavelengths more than other wavelengths

Question 4. The role of phycobilins in photosynthesis is to :

1. Absorb and transfer energy to chlorophyll
2. Donate electrons to the electron transport
3. Fix carbon dioxide
4. Carry hydrogen or electrons.

Answer: 1. Absorb and transfer energy to chlorophyll

Read and Learn More NEET Biology Multiple Choice Question and Answers

Solute Transport And Translocation MCQ Question 5. A cell that lacks chloroplast does not:

1. Evolve carbon dioxide
2. Liberate oxygen
3. Require water
4. Utilize carbohydrates.

Answer: 2. Liberate oxygen

Question 6. Energy is transferred from the light reaction step to the dark reaction step by :

1. Chlorophyll
2. ADP
3. ATP
4. RuBP.

Answer: 3. ATP

Question 7. The thylakoids are removed and kept in a culture medium containing C02 and H2. If the set-up is exposed to light, hexose sugar are not formed as the end product. The most appropriate reason for this will be :

1. The light trapping device is non-functional
2. Enzymes involved in CO2 imitation are not available for the process.
3. The pigment (P?Q0 and P680) are not linked
4. Carbon assimilation cannot take, place in the light.

Answer: 2. Enzymes involved in CO2 imitation are not available for the process.

Question 8. In photosynthesis the oxygen evolveci1 and oxygen in glucose come from :

1. H90 and C02 respectively
2. H20
3. co2
4. C02 and H20 respectively.

Answer: 1. H90 and C02 respectively

Question 9. Algae float in the water during day time and sink during night time because :

1. They become light due to the consumption of food materials in respiration
2. They lose weight at night
3. They come up to enjoy the sunshine
4. They become buoyant in light due to the accumulation of oxygen bubbles released in photosynthesis.

Answer: 4. They become buoyant in light due to the accumulation of oxygen bubbles released in photosynthesis.

Solute Transport And Translocation MCQ Question 10. Quantosome contains :

1. 200 chlorophyll molecules
2. 230 chlorophyll molecules
3. 250 chlorophyll molecules
4. 300 chlorophyll molecules.

Answer : 3. 250 chlorophyll molecules

Question 11. In photosynthesis chlorophyll serves as :

1. Hydrogen acceptor
2. A raw material
3. An energy converter
4. As end product.

Answer : 3. An energy converter

Question 12. The first step in photosynthesis is :

1. Absorption of light by Pigment system I
2. Production of ATP and NADPH2
3. Absorption of light by chlorophylls of both Pigment systems I and II
4. Production of ATP.

Answer : 3. Absorption of light by chlorophylls of both Pigment systems I and II

Question 13. “Assimilatory Power” is :

1. ATP
2. NADPH2
3. Both (A) and (B)
4. solar energy.

Answer : 3. Both (A) and (B)

Question 14. In C3 plants initial acceptor of C02 is :

1. fructose 6-P04
2. Ribulose 1, 5 diphosphate
3. Ribulose phosphate
4. Xylulose 5-P04.

Answer: 2. Ribulose 1, 5 diphosphate

Solute Transport And Translocation MCQ Question 15. The site of dark reaction in plastid is :

1. Granal lamella
2. Stroma
3. Stromal lamella
4. Outer membrane.

Answer: 2. Stroma

Question 16. The products of the light reaction in photosynthesis are :

1. ADP and Glucose
2. ATP and NADPH2
3. Ferredoxin and Cytochrome b6.
4. Plastoquinone and Cytochrome

Answer: 2. ATP and NADPH2

Question 17. Chloroplasts fix:

1. 02
2. H2
3. C02
4. N2.

Answer: 3. C02

Question 18. The first stable product of carbon assi£nilation in C3 plants is: etc 

1. 3-Phosphoglyceraldehyde
2. Glucose otorlq.
3. Starch
4. Pyruvic acid.

Answer: 1. 3-Phosphoglyceraldehyde

Question 19. All photosynthetic green plants contain :

1. chlorophyll a
2. Chlorophyll b
3. Chlorophyll c
4. Chlorophyll d.

Answer: 1. chlorophyll a

Question 20. The principle of limiting factor was proposed by :

1. Stephen Hales
2. Ingenhousz
3. Blackman
4. Calvin.

Answer: 3. Blackman

Solute Transport And Translocation MCQ Question 21. The sequence of dark reaction of photosynthesis was discovered by :

1. Blackman
2. Calvin
3. Robin Hill
4. Levitt.

Answer: 2. Calvin

Question 22. Photophosphorylation takes place :

1. During day time
2. During night
3. During both day and night
4. On rainy days only.

Answer: 1. During day time

Question 23. The process of conversion of light energy into chemical energy is called :

1. Photoperiodism
2. Photophosphorylation
3. Phototropism
4. Photolysis.

Answer: 2. Photophosphorylation

Question 24. In C4 plants carbon dioxide is initially fixed with :

1. Adenosine triphosphate
2. Ribulose diphosphate
3. Phosphoenol pyruvate
4. Citric acid.

Answer: 3. Phosphoenolpyruvate

Question 25. Etiolated plants are formed due to a lack of:

1. Light
2. Hg
3. Fe
4. Mg.

Answer: 1. Light

Transport In Plants MCQ  Question 26. In photosystem I, the trap centre of energy is :

1. P 700
2. Carotene
3. P 680
4. Xanthophyll.

Answer: 1. P 700

Question 27. In photosystem II, the trap centre of energy is :

1. P-700
2. Carotene
3. P-680
4. Xanthophyll.

Answer: 3. P-680

Question 28. In Photosynthesis, the sunlight :

1. Is converted into kinetic energy
2. Is converted into chemical energy
3. Is used as a catalyst.
4. Plays no role.

Answer: 2. Is converted into chemical energy

Question 29. The role of light in photosynthesis was discovered by :

1. Priestley
2. Von Helmont
3. Ingenhousz
4. De Saussure.

Answer: 3. Ingenhousz

Transport In Plants MCQ  Question 30. The role of chlorophyll in photosynthesis is the absorption :

1. And decomposition of water
2. Of C02 and water
3. Of light and photolysis of water
4. Of strong light in the form of chemical energy.

Answer: 3. Of light and photolysis of water

Question 31. During photosynthesis the C02 as one of the raw materials enters and leaves through :

1. Lenticels
2. Hydathodes
3. Stomata
4. The general surface of leaves.

Answer: 3. Stomata

Question 32. The ratio of the volume of 02 liberated to the volume of C02 absorbed during photosynthesis is known as :

1. Respiratory quotient
2. Photosynthetic quotient ‘
3. Tidal volume
4. Expiratory reserve volume.

Answer: 2. Photosynthetic quotient ‘

Question 33. The Hill (Light) reaction or photochemical phase of photosynthesis results in the production of:

1. ATP
2. 02
3. NADPH2
4. All the above.

Answer: 4. All the above.

Question 34. Which clement is essential for the photolysis of water 7

1. Nitrogen
2. Chlorine
3. Carbon
4. Oxygen.

Answer: 2. Chlorine

Question 35. In which of the following phases of photosynthesis is C02 usually utilised?

1. Photochemical phase
2. Photolysis
3. Photophosphorylation
4. Dark reaction,

Answer: 4. Dark reaction,

Transport In Plants MCQ  Question 36. In C4 plants initial C02 fixation takes place in the chloroplasts of:

1. Guard cells
2. Spongy mesophyll
3. Palisade tissue
4. Bundle sheath.

Answer: 2. Spongy mesophyll

Question 37. What happens during photosynthetic phosphorylation?

1. ATP is formed
2. ATP is not formed
3. 02 is evolved from C02
4. Water does not join the process.

Answer: 1. ATP is formed

Question 38. In a chloroplast, the site for the light reaction is :

1. Grana
2. Stroma
3. Lamella
4. Unit membrane.

Answer: 1. GranaGrana

Question 39. Leaves appear green because they :

1. Absorb green light
2. Reflect green light
3. Both absorb and reflect green light
4. None of the above.

Answer: 2. Reflect green light

Question 40. Which is a C4 plant?

1. Tomato
2. Saccharum
3. Potato
4. Pea.

Answer: 2. Saccharum

Transport In Plants MCQ  Question 41. C4 plants are different from C3 plants with reference to the following :

1. Types of end products of photosynthesis
2. The initial acceptor of C02 is phosphoenol pyruvate
3. Types of pigments involved.
4. No ATP was consumed.

Answer: 2. Initial acceptor of C02 is phosphoenol pyruvate

Question 42. Photorespiration includes :

1. Hatch and Slack’s cycle
2. Glycolate cycle x
3. Krebs’ cycle
4. Calvin cycle.

Answer: 2. Glycolate cycle x

Question 43. Photorespiration takes place only in:

1. Green parts of the plant
2. All the living cells of the plant
3. Mitochondria
4. Root.

Answer: 1. Green parts of the plant

Question 44. The leads appear yellow when grown in :

1. Light
2. dark
3. At Hig temperature
4. At low temperatures.

Answer: 2. dark

Question 45. In the process of photosynthesis, the first step is :

1. Absorption of CO0
2. Absorption of 02
3. Excitation of an electron of chlorophyll by a photon of light
4. Photolysis of water.

Answer: 3. Excitation of an electron of chlorophyll by a photon of light

Question 46. The substrate for photorespiration is :

1. Aspartate
2. Malate
3. Pyruvate
4. Glycolate.

Answer: 4. Glycolate.

Important MCQs On Photosynthesis Question 47. Chlorophyll ‘a’ is characterized by the side group of:

1. Phytol
2. Keto
3. Methyl
4. Aldehyde.

Answer: 3. Methyl

Question 48. Assimilatory powers produced during photosynthesis are:

1. H20 and 02
2. RuDP and RuMP
3. C6H1206 and PGAL
4. ATP and NADPH2.

Answer: 4. ATP and NADPH2.

Question 49. C4 plants differ from C3 plants with respect to :

1. Number of ATP molecules consumed
2. First product
3. The substrate which accepts carbon dioxide
4. All the above.

Answer: 2. First product

Question 50. C02 fixation during C4 pathways occurs in the chloro- plast of:

1. Guard cells
2. Bundle sheath cells
3. Spongy parenchyma
4. Mesophyll cells.

Answer: 2. Bundle sheath cells

Important MCQs On Photosynthesis Question 51. In plants, the synthesis of chlorophyll occurs in the presence of

1. Phytochrome
2. Cytochrome
3. Light
4. None of the above.

Answer: 3. Light

Question 52. Persons who got Nobel Prizes for their work in photosynthesis are :

1. Calvin and Borlang
2. Calvin and Benson
3. Beadle and Tatum
4. Flemming and Waksman.

Answer: 2. Calvin and Benson

Question 53. Chlorophyll is soluble :

1. In water
2. In organic solvents
3. In H20 and organic acids
4. None of these.

Answer: 2. In organic solvents

Question 54. The process of photophosphorylation was studied by :

1. Calvin
2. Amon
3. Priestley
4. Blackman.

Answer: 2. Amon

Question 55. The ‘Dark Reaction’ in photosynthesis is called so because it :

1. Cannot occur in light
2. Needs only darkness
3. Does not require light energy
4. Occurs more rapidly at night.

Answer: 3. Does not require light energy

Important MCQs On Photosynthesis Question 56. In photosynthesis‘02 is liberated due to :

1. Hydrolysis of carbohydrates
2. Breakdown Of Chlorophyll
3. Photolysis of water
4. Reduction of Carbon dioxide.

Answer: 3. Photolysis of water

Question 57. The correct formula of chlorophyll ‘a’ is :

1. C₅₅H₇₂O₅N₄Mg
2. C₅₅H₇₀O₆N₄Mg
3. C₅₅H₇₄0₅N₄Mg
4. C₅₅H₇₀O₅M₅Mg.

Answer: 1. C₅₅H₇₂O₅N₄Mg

Question 58. Agranal chloroplasts are a characteristic feature of one of the following: ’

1. Bundle sheath of sugarcane leaves
2. Mesophyll of Pea leaves
3. Bundle sheath of mango leaves
4. Mesophyll of maize leaves.

Answer: 1. Bundle sheath of sugarcane leaves

Question 59. Which of the following is present at 3 carbon atoms of n pyrrole ring of chlorophyll a molecule?

1. Aldehyde group
2. Carboxyl group
3. Methyl group
4. Mg.

Answer: 4. Mg.

Question 60. Which of the following occurs in the C3 cycle?

1. Reductive carboxylation
2. Oxidative carboxylation
3. Photophosphorylation
4. Oxidative phosphorylation.

Answer: 1. Reductive carboxylation

Photosynthesis MCQ Question 61. Which of the following wavelengths is active in view of photosynthesis?

1. 400—500 nm
2. 400—700 nm
3. 200-150 nm
4. 510—600 nm.

Answer: 2. 400—700 nm

Question 62. Which pigment is absent in chloroplast? ,

1. Chlorophyll
2. Anthocyanin
3. Xanthophylls
4. Carotenoids.

Answer: 2. Anthocyanin

Question 63. The C4 cycle was discovered by :

1. Calvin
2. Hatch and Slacks
3. Amon
4. Blackman.

Answer: 2. Hatch and Slacks

Question 64. The plant which is used for the study of photosynthesis research is:

1. Chlamydomonas
2. Chlorella
3. Hydrilla
4. Spinach leaves.

Answer: 2. Chlorella

Photosynthesis MCQ Question 65. Chlorophyll absorbs :

1. Red light
2. Blue light
3. Greenlight
4. Both blue and red light.

Answer: 4. Both blue and red light.

Question 66. The Discovery of the Emerson effect has shown the existence of:

1. Light and dark reaction
2. Photorespiration
3. Photophosphorylation
4. Two distinct pigment systems.

Answer: 4. Two distinct pigment systems.

Question 67. Starch is detected in the leaf:

1. By white appearance
2. With iodine solution
3. Starch granules
4. Presence of an energy store.

Answer: 2. With iodine solution

Question 68. Cyclic phosphorylation produces :

1. ATP and NADPH2.
2. NADPH2 only
3. ATP only
4. ATP, NADPH2 and 02.

Answer: 3. ATP only

Question 69. The path of the C02 molecule during the dark reaction of photosynthesis was successfully traced by the use of :

1. X-rays
2. O18
3. C14
4. p32

Answer: 3. C14

Photosynthesis MCQ uestion 70. Maximal rates of |photosynthesis are obtained in the:

1. Greenlight
2. Red light
3. Far-red
4. Ultraviolet.

Answer: 2. Red light

Question 71. In C4 plants, C02 is first fixed in:

1. Palisade parenchyma
2. Guard cells
3. Bundle sheath
4. Spongy mesophyll

Answer: 4. Spongy mesophyll

Question 72. The electron donor in the photosynthetic process taking place in the eukaryotic plants is:

1. H2S
2. CO2
3. ATP
4. H20.

Answer: 4. H20.

Question 73. Tropical plants show high efficiency of C02 fixation because of:

1. Calvin cycle
2. Hatch and Slack pathway
3. EMP pathway
4. Krebs’ cycle.

Answer: 2. Hatch and Slack pathway

Photosynthesis MCQ Question 74. Which of the following enzymes is used for the carboxylation of RuDP?

1. carboxylase
2. Ribulose diphosphate carboxylase
3. Peroxidase
4. Phosphopentokinase.

Answer: 2. Ribulose diphosphate carboxylase

Question 75. Q10 is:

1. The respiratory quotient
2. Temperature coefficient
3. Constant in the quantum equation
4. A scale of quality.

Answer: 2. Temperature co-efficient

Question 76. Grana refers to :

1. Stacks of thylakoids in plastids of higher plants
2. A constant in the quantum equation
3. Glycolysis of glucose
4. A by-product of photosynthesis.

Answer: 1. Stacks of thylakoids in plastids of higher plants

Question 77. When a green cell transfers light energy into chemical energy which of the following reactions would take place?

1. ADP + iP = ATP
2. ATP – iP =s ADP
3. AMP + iP = AFP
4. GDP + P = GTP.

Answer: 1. ADP + iP = ATP

Question 78. Starch containing plastids are termed :

1. Chloroplasts
2. Chromoplasts
3. Amyloplasts
4. Leucoplasts.

Answer: 3. Amyloplasts

Photosynthesis MCQ Question 79. The electron carriers which in close association with photosynthetic pigment systems form an electron transport chain are :

1. Present in the cytoplasm
2. Present on the outer membrane of green plastids
3. Bound to thylakoids
4. Dissolved in stroma of chloroplasts.

Answer: 3. Bound to thylakoids

Question 80. Photorespiration is favoured by :

1. High 02 and low C09
2. Low 02 and high C02
3. Low temperature and high 02
4. Low light and high 02.

Answer: 1. High 02 and low C09

Question 81. Which of the following statements is correct about the C4 type of photosynthesis?

1. The C4 cycle is an independent cycle
2. The C4 cycle is adjunct to the Calvin cycle
3. RuBP carboxylase has a higher affinity for CC)2
4. Carboxylase is present in the bundle sheath cells.

Answer: 2. The C4 cycle is adjunct to the Calvin cycle

Question 82. C02 is used during :

1. Light reaction
2. Dark reaction
3. Photolysis
4. Grana.

Answer: 2. Dark reaction

Question 83. NADP+ is reduced to NADPH2 in:

1. Photosystem-I
2. Photosystem-II
3. Photolysis
4. Krebs’ cycle.

Answer: 2. Photosystem-II

Question 84. The light energy used by the higher plants for photo¬synthesis is only about:

1. 1-2%
2. 30%
3. 70%
4. 85%.

Answer: 1. 1-2%

Solute Transport And Translocation MCQ Question 85. Calvin used which plant to trace out the carbon path.

1. Spirogyra
2. Chlamydomonas
3. Chlorococcum
4. Chlorella and Scenedesmus.

Answer: 4. Chlorella and Scenedesmus.

Question 86. Calvin cycle was investigated by the use of:

1. C12
2. O16
3. C16
4. C14.

Answer: 4. C14.

Question 87. Photorespiration is favoured by :

1. High 02 and low C02 levels
2. Low light intensity
3. Low 02 and high CO-, levels
4. Low temperature.

Answer: 1. High 02 and low C02 levels

Question 88. The isotopes that have proved useful in research on photosynthesis are :

1. O18 and O14
2. C11 andP32
3. P32 and O18
4. C14 and O18.

Answer: 4. C14 and O18

Question 89. Photosynthesis rate per unit of light energy would be more in:

1. Intermittent sunlight
2. Normal sunlight
3. Bright regular sunlight
4. Weak sunlight.

Answer: 1. Intermittent sunlight

Solute Transport And Translocation MCQ Question 90. What is the smallest photosynthetically functional unit?

1. Photon
2. Electron
3. Quantosome
4. Chlorophyll.

Answer: 3. Quantosome

Question 91. Which one of the following crops is an efficient converter of solar energy and has a net productivity value of 2 to 4 kg. m2 per year?

1. Bajra
2. Sugarcane
3. Wheat
4. Rice.

Answer: 2. Sugarcane

Question 92. In the C4 plants, the C4 cycle occurs in the mesophyll cells and the C3 cycle occurs in the bundle sheath cells. But in CAM plants:

1. C4 and C3 cycles occur in the mesophyll cells only
2. The C4 cycle occurs very rarely.
3. The C4 cycle occurs in bundle sheath cells and the C3 cycle in mesophyll cells; to
4. C4 and C3 cycles occur in bundle sheath cells.

Answer: 1. C4 and C3 cycles occur in the mesophyll cells only

Question 93. Photorespiration occurs in :

1. C3 plants
2. All plants
3. Algae only
4. C4 plant

Answer: 1. C3 plants

Question 94. The plants like sugarcane, maize^Qypenis etc. show high efficiency^ ,C02 fixation because of:

1. Hatch-Slack cycle
2. Photophosphorylation
3. Blackman’s law of limiting factor
4. Calvin cycle.

Answer: 1. Hatch-Slack cycle

Question 95. Photosynthetic rate is independent of:

1. temperature
2. Light intensity
3. Light quality
4. Light duration.

Answer: 4. Light duration.

Solute Transport And Translocation MCQ Question 96. In C4 plants. Calvin cycle

1. Does not operate because PEP carboxylase fixes most of the CO, and leaves only a little of it for Calvin cycle
2. Operates in the stroma of bundle sheath
3. Operates in the grana of bundle sheath chloroplast
4. Operates in the mesophyll chloroplast only.

Answer: 2. Operates in the stroma of bundle sheath

Question 97. Which one of the following is the most appropriate reason for storing green-coloured apples at low temperatures?

1. Photosynthesis and respiration are completely inhibited
2. The rate of respiration is reduced
3. The rate of photosynthesis is reduced
4. The rate of photosynthesis and respiration are reduced.

Answer: 4. Rate of photosynthesis and respiration are reduced.

Question 98. The specific function of light energy in the photosynthesis process is to :

1. Activate chlorophyll
2. Split water
3. Reduce CO,
4. Synthesise glucose.

Answer: 2. Split water

Solute Transport And Translocation MCQ Question 99. Which of the following wavelengths of light is absorbed maximum for photosynthesis?

1. 640 nm
2. 440 nm
3. 680 nm
4. 700 nm.

Answer: 3. 680 nm

Question 100. Quanta required for assimilation of one mol. of CO,/0, liberation in photosynthesis are :

1. 8
2. 6
3. 4
4. 2.

Answer: 1. 8

Question 101. In an experiment to demonstrate the liberation of oxygen during photosynthesis in a fresh spring of the aquatic plant Hydrilla, 2 sets were arranged. The first set was with ordinary tap water (control set-up) and the second set was with an equal volume of brown aerated water. The evolution of Of, bubbles in the brown aerated water set will :

1. Increase only initially
2. Rapidly decrease
3. Remain unaltered
4. Cease to occur almost instantaneously.

Answer: 2. Rapidly decrease

Question 102. Which of the following is not a C4 plant?

1. Cyperus
2. Potato
3. Saccharum officinarum
4. All the above.

Answer: 2. Potato

Question 103. Purple sulphur bacteria are :

1. Saprophytic
2. Chemosynthetic
3. Heterotrophic
4. Photosynthetic.

Answer: 4. Photosynthetic

Question 104. The connecting link between respiration and photosynthesis is :

1. Ribulose-1, 5-diphosphate
2. 3-phosphoglyceraldehyde
3. Glucose
4. Sedo heptulose-1, 7, diphosphate.

Answer: 2. 3-phosphoglyceraldehyde

Question 105. Non-cyclic photophosphorylation involves :

1. Pigment system II only
2. Pigment system I only
3. Both pigment systems I and II
4. None of the above.

Answer: 3. Both pigment systems I and II

Solute Transport And Translocation MCQ Question 106. The pigment that absorbs red and far-red light in plants is:

1. Cytochrome
2. Xanthophyll
3. Phytochrome
4. Carotene.

Answer: 3. Phytochrome

Question 107. When PGA is changed into phosphoglyceraldehyde during photosynthesis, which of the following reactions occurs?

1. Oxidation
2. Reduction
3. Electrolysis
4. Hydrolysis.

Answer: 2. Reduction

Question 108. During ATP synthesis, electrons pass through :

1. C02
2. 02
3. H20
4. Cytochromes.

Answer: 4. Cytochromes.

Question 109. 85-90% (or nine-tenth) of all the photosynthesis of the world is carried out by :

1. Large trees with millions of branches and leaves
2. Algae of the ocean
3. Ferns of forest
4. Scientists in the laboratory.

Answer: 2. Algae of the ocean

Question 110. Chemiosmosis requires a membrane, a proton pump and :

1. ATPase only
2. Proton gradient
3. NADPH
4. Proton gradient and ATPs

Answer: 4. Proton gradient and ATPs

Question 111. The main difference between the two light reactions of photosynthesis is :

1. Photosystem I emits electrons to be transferred to Photosystem II
2. Photosystem I generates strong reductant NADPH and Photosystem II a strong oxidant
3. Photosystem I produces a strong oxidant and photosystem II a strong reductant NADPH
4. Photosystem I produces ATP while Photosystem II does not produce ATP.

Answer: 2. Photosystem I generates strong reductant NADPH and Photosystem II a strong oxidant

Important MCQs On Photosynthesis Question 112. The C4 plants show :

1. Higher transpiration and no photorespiration
2. Low transpiration and no photorespiration
3. High transpiration and photorespiration
4. Low transpiration and photorespiration.

Answer: 2. Low transpiration and no photorespiration

Question 113. The light reactions of photosynthesis are initiated by :

1. P 700 and P 680
2. P 700, P 680 and Chi. b
3. All components of chi. a
4. P 700, P 695, P 680 and Chi. b.

Answer: 1. P 700 and P 680

Question 114. According to a recent Z-scheme, the electron released on behalf of PS II is accepted by :

1. Quinone
2. Ferredoxin
3. F.R.S.
4. Phaeophytin.

Answer: 1. Quinone

Question 115. The gap electron of PS II is filled due to the supply of electrons from :

1. Plastocyanin
2. Plastoquinone
3. Photolysis of water
4. Fe-S protein.

Answer: 3. Photolysis of water

Question 116. The PS II is thought to be bound to :

1. Mn-Protein
2. Fe-S protein iL
3. Quinones
4. Cytochromes.

Answer: 1. Mn-Protein

Question 117. If isolated chloroplasts suspended in an aqueous medium are supplied with inorganic phosphates, ADP, and NADP are illuminated they show :

1. Complete photosynthesis
2. Only Hill reaction
3. Only cyclic phosphorylation
4. Non-cyclic photophosphorylation.

Answer: 4. Non-cyclic photophosphorylation.

Important MCQs On Photosynthesis Question 118. The scientist who discovered atmospheric CO, concentration to be suboptimal for photosynthesis is :

1. Godlewski
2. Bossingault
3. Dutrochet
4. De Saussure.

Answer: 1. Godlewski

Question 119. Wilmott’s bubbler is meant to prove:

1. CO is necessary for photosynthesis
2. Light is necessary for photosynthesis
3. Oxygen is evolved during photosynthesis
4. Chlorophyll is essential for photosynthesis.

Answer: 3. Oxygen is evolved during photosynthesis

Question 120. The sap that flows out of the tire stem comes from :

1. xylem
2. Phloem
3. Medullary rays
4. Pith.

Answer: 2. Phloem

Question 121. Though potato tubers do not manufacture organic food, it is stored in them in large amounts. This is due to :

1. Conversion of starch into the tuber
2. Synthesis of food in the leaves, its translocation to the tubers and conversion into starch
3. Synthesis of hexose sugar
4. Formation of sugars and their conversion into starch in the tubers themselves.

Answer: 2. Synthesis of food in the leaves, its translocation to the tubers and conversion into s

Question 122. C4 plants are better adapted to tropical and desert areas because:

1. Sunlight is more intense and the growing season is longer
2. They can maintain a high rate of photosynthesis under water stress conditions
3. They possess chloroplasts only in bundles in bundle sheaths
4. Of all the above.

Answer: 3. They possess chloroplasts only in bundles in bundle sheaths

Question 123. In the following diagram if A represents water and carbon dioxide then

1. I is photosynthesis, El is respiration and B is CH20 and oxygen
2. I-is photosynthesis, Il-is respiration and B is C02 and H20
3. I is respiration, II is photosynthesis and B is CH20 and O,
4. I is respiration, II is photosynthesis and B is C02 and water.

Answer: 3. I is respiration, II is photosynthesis and B is CH20 and O,

Question 124. The difference between NAD+ and NADP4- is :

1. One carries electrons to the electron transport system and the other carries them to synthetic reactions
2. Only NAD+ production requires niacin in the diet
3. One contains high-energy phosphate bonds and the other does not
4. All of the above are correct.

Answer: 1. One carries electrons to the electron transport system and the other carries them to synthetic reactions

Question 125. A major drawback of Munch’s hypothesis is :

1. It involves a turgor pressure gradient
2. It explains unidirectional flow only
3. It involves permeability throughout the mass
4. Translocation is by the mass flow of solutes.

Answer: 2. It explains unidirectional flow only

Question 126. ‘High energy’ electrons from PS-I pass to NADP where they combine with hydrogen ions, which come from the initial photolysis of water, to form :

1. ADP
2. NADPH2
3. FAD
4. NAD.

Answer: 2. NADPH2

Question 127. In C4 plants, as opposed to C3 plants, the enzyme PEPase fixes carbon dioxide to PEP to form :

1. Phosphoglycerate
2. Oxalo succinate
3. Oxaloacetate
4. Dihydroxy acetone phosphate.

Answer: 3. Oxaloacetate

Question 128. If the plant is first exposed to light of 7300 A length and then to light of 6600 A, the plant:

1. Will show inhibited growth activity
2. Will resume normal growth activity
3. Will not grow at all
4. Will die.

Answer: 2. Will resume normal growth activity

Question 129. The cyclic electron pathway begins after :

1. Photosystem I complex absorbs solar energy
2. Photosystem II complex absorbs solar energy
3. Both photosystem I and II absorb solar energy
4. None of the above.

Answer: 2. Photosystem II complex absorbs solar energy

NEET Biology Photosynthesis And Translocation Of Organic Solutes

The food is manufactured by green parts of the plants by the process of photosynthesis. In the presence of sunlight. CO₂ and water, green parts synthesize carbohydrates and liberate O₂.

• The pigments needed are chlorophyll, carotenes, xanthophylls and phycobilins. The cells have chloroplasts which are semi-autonomous cell organelles, double membranous structures with matrix, and stroma. DNA. RNA, grana etc.
• The mechanism involves light and dark reactions. The light reaction needs light in which there is photolysis of water, photophosphorylation, formation of assimilatory power (NADPH, and ATP) and O₂ is released. Phosphorylation may be cyclic or non-cyclic.
• The dark reaction, as the name indicates, does not require light but continues even in the presence of light. Various reactions are in the form of a cycle called the Calvin cycle.
• Ribulose 1,5 diphosphate is the initial acceptor of CO^–, to produce phosphoglyceric acid (3-carbon compound). It utilises assimilatory power (NADPH₂, ATP) to produce 3 phosphoglyceraldehyde.
• A part of it is converted into carbohydrates while the remaining part is converted in a series of reactions into Ribulose 1,5 diphosphate. So there is cyclic production and utilization of this compound. On one side CO₂, ATP and NADPH₂ are used while on the other side, carbohydrates are produced.
• Plants showing the above mechanism are called C₃ plants as the first stable product is 3- phospho-glyceraldehyde. In C₄ plants, the first stable product is oxaloacetic acid. Important Events in the Discovery of Photosynthesis

Read and Learn More NEET Biology Notes

NEET Biology Photosynthesis And Translocation Of Organic Solutes Important Events In The Discovery Of Photosynthesis

• Aristotle and Theophrastus (370 B.C.) believed that plants get their food supply from organic matter in the soil by absorption.
• Ancient Indians believed that plants feed from their feet.
• Van Helmont (1648). He experimented with a small willow twig and concluded that “All vegetation is only water.”
• Woodward (1699) concluded by his experiments that when water is absorbed from the soil, certain material for growth is also made available to the plant.
• Stephen Hales (1727) often known as the ‘Father of Plant Physiology’ was the first to say that leaves to manufacture the food and light may play some role in manufacturing the food.
• Priestley (1722) gave the elementary idea of gaseous exchange, due to which the atmosphere remains pure. He concluded that vegetation purifies the air.
• Ingenhousz (1779) propounded the view that light and chlorophyll play a definite role in photosynthesis. He gave the following reaction for photosynthesis.
  Plants
• Lavoisier (1783) identified the purifying principle produced by green plants in sunlight as oxygen and the noxious air produced by the burning of candles as CO₂ (phlogiston).
• Senebier (1782) gave the idea that as the concentration of CO₂ is increased, the rate of evolution of O₂ also increases.
• Jean Senebier (1800) said that O₂ is released from CO₂ from green plants. He further said that red light of the visible spectrum is the best light for the process of photosynthesis.
• Dutrochet (1837) confirmed by his experiments that chlorophyll is necessary for the process of photosynthesis.
• De Saussure (I804) gave the following additions:
• Importance of water in the process.
• CO₂ is absorbed by plants instead of carbonic acid.
• Another significant breakthrough was the discovery of the fact that CO7 absorbed is equal to oxygen released.
• Von Mayer (1845) gave the following equation :
• CO₂ + H₂O + light energy Green Plants ^ Organic matter + chemical energy + O₂
• Lcibig 0845) pointed out that organic matter was derived from CO, and water was used in the photosynthesis.
• Sachs et al 0 887) concluded that chloroplasts use CO₂ to release O₂ He found starch as the first visible food.
• Engelmann 0888) plotted the action spectrum of photosynthesis.
• Blackman 0905) introduced Blackman’s law of limiting factor.
• Warburg 0 920) introduced the unicellular green alga chlorella as a suitable material to study photosynthesis.
• Van Neil 0930) established the foundation of a new era for solving the mystery of photosynthesis by concluding that 02 is released from H,0 and not from CO₂
• Robin Hill 0939) demonstrated that separate light reactions were present in a chloroplast.
• Ruben and Kamen 0941) used radioactive O18 to confirm that O₂ released is produced from H,O₂

1. Amon (1954) found that light and dark reactions are separable.
2. Emerson (1957) showed a red drop and the Emerson effect.
3. Amon (1967) proposed a scheme for the existence of two photosystems in the light phase.
4. Hatch and Slack (1965) formulated the Hatch and Slack cycle of C₄ plants for fixation of CO₂.
5. Rouhani et al, (1973) introduced the CAM pathways in the Sedum plants.
6. Huber, Michael and Dissenhofer (1985) crystallized the photosynthetic centre of the bacterium Rhodobacter and analysed its structure by X-ray Diffraction technique. They were awarded the Nobel Prize in Chemistry (1988).
7. Peftilier and Caventon (1818) coined the term chlorophyll.
8. G.G. Stokes was the first to separate pure fractions of chlorophyll-u and chlorophyll-b
9. Willstatter and Stoll (1913) were the pioneers in the studies of chlorophyll synthesis.
10. Menke (1961) stated that thylakoids are the structural and functional units of chloroplasts.
11. Park and Biggins coined the term quantosomes.
12. Photosynthetic Pigments

Ingenhousz (1779) recognised the participation of chlorophyll and light in the photosynthetic process. However, it is well-known now that besides chlorophyll, other pigments such as carotenoids and phycobilins are also involved in light absorption during photosynthesis.

• Chlorophylls The chlorophylls are the most important pigments active in photosynthesis. Today at least 9 types of Chlorophylls may be distinguished.
• Chlorophyll a (C₅₅H₇₂O₅N₄Mg Universal (ii) Chlorophyll b (C₅₅H₇₀O₆N₄Mg) Almost universal (Hi) Chlorophyll c (C35H7205N4Mg) Brown algae and diatoms etc O’v) Chlorophyll d (C₅₅H₇₀O₆N₄Mg) Red Algae
• Chlorophyll e (empirical formula not known) Xanthophyta
• Bacteriochlorophyll! a (C₅₅H₇₀O₆N₄Mg) Most of bacteria
• Bacteriochlorophylls b (formula not known) Rhodopseudomonas
• Chlorobium chlorophyll a (Bactcrioviridin) 650 (formula not known) Chloropium.
• Chlorobium chlorophyll (Bacterioviridin) 660 (formula not known)
• Chlorophyll a is bluish-green while chlorophyll b is olive green. Chlorophyll has a nyrrole porphyrin head (15 x 15 A) and a long-chain alcohol called phytol (20 A).
• Chlorophyll a has a methyl group at carbon 3 while chlorophyll b has a formyl (= aldehyde) group attached to this atom. Phytol is attached to carbon 7 through a propionic acid residue. The porphyrin head contains Mg (non-ionic) in its centre.
• Carotenoids. Carotenoids tire lipid compounds which are thought to be the derivatives of lycopene, a pigment present in tomatoes. They are present in nearly all higher plants, algae and many microorganisms, and are of two types:
• Carotenes. They are orange-yellow and are composed of carbon and hydrogen. They are insoluble in water but soluble in chloroform, ether and carbon disulphide. Four isomeric fonts of carotenes are now recognised: a, (3, y and 5 of which P- carotene is most common in all green plants and is readily converted into vitamin A in animal bodies.
• Xanthophylls or Carotenoids. They are yellow with the empirical formula C₄0H₅₆O₂. In normal green leaves, proportionately there is more xanthophyll than carotene and the most common xanthophyll in green leaves is luteol or lutein.
• Carotenoids, like chlorophylls, are located in the chloroplast and the chromatophore. Goodwin (1960) suggested that the chlorophylls and carotenoids may be attached to the same protein, forming a complex known as photosynthesis.
• Phycobilins or Biliproteins. They are protein-linked pigments which are easily destroyed by heat. They are soluble in hot water and are of three types:
• Phycocyanin. It is mostly found in blue-green algae and a few red algae.
• Phycoerythrin. It is mostly found in red algae and a few brown algae. Red algae growing in deep sea water show the highest efficiency of photosynthesis in green light which penetrates farthest in clear water and is absorbed by phycoerythrin, a red pigment present in them.
• Allophycocyanins. It is found in both blue-green and red algae.

NEET Biology Photosynthesis And Translocation Of Organic Solutes Quantosome

• Park and Biggins (1964) coined the term for a group of pigment molecules required for carrying out a photochemical reaction. Quantosomes are present as small units on the membranes of thylakoids.
• Each quant some consists of about 250-300 chlorophyll molecules, carotenoids, quinone compounds, sulpholipids, phospholipids, proteins etc. including special types of chlorophyll molecules :
• P6g0 and P700 (P = Pigment; 680 and 700 denote the wavelength of light these molecules absorb).
• P680 and P700 constitute the reaction centre (or photocentres). Other accessory pigments and chlorophyll molecules are light-gatherers or antenna molecules (capture solar energy and transfer it onto the reaction centres by resonance transfer or inductive resonance).

NEET Biology Photosynthesis And Translocation Of Organic Solutes Absorption And Action Spectra

An action spectrum is a graph showing the rate of a process (e.g. photosynthesis) at different wavelengths of light. An absorption spectrum is a graph showing the amount of light of different wavelengths absorbed by a pigment.

The close similarity between the action spectrum of photosynthesis and the absorption spectrum of chlorophyll shows that chlorophylls are responsible for the absorption of light in photosynthesis.

NEET Biology Photosynthesis And Translocation Of Organic Solutes Photosystem 1 And Photosystem 2

• Emerson’s enhancement effect. Emerson and Lewis (1943) observed a sudden drop in photosynthetic yield (evolution of O₂) by Clilorella above 680 mn (far red) – redtdrop. But if red light of shorter wavelength was also supplied simultaneously, photosynthetic yield increased (enhancement effect).
• Hence, Emerson (1957) proposed that two pigment systems or photochemical reaction systems are involved in the light phase (which act synergistically).
• A photon absorbed anywhere in the trapping (or harvesting) zone of a P6g0 centre can pass its energy to the P680 molecule. The cluster of pigment molecules which transfer their energy to P680 absorb light at or below the wavelength of 680 runs.
• Along with these molecules make tip the Photosystem II or PS II In the same way.P700 along with accessory pigments which absorb at or below 700 constitute the Photosystem I or PS I. PS I is located both in Stroma and Grana Lamellae. PS II is located in Grana. It possesses chlorophyll a. chlorophyll b and carotenoids.

NEET Biology Photosynthesis And Translocation Of Organic Solutes Photophosphorylation Light phase

• Arnon et al (1954) discovered that isolated chloroplasts could synthesise ATP in the presence of light. Such a light-driven formation of ATP was called photophosphorylation.
• This is accompanied by photolysis of water, as a result of which O₂ is released and H combines with N’.ADP to form NADPH. Photophosphorylation can be defined as the coupling of phosphate with ADP to produce ATP using light energy during photosynthesis.
• Cyclic photophosphorylation. When the photons activate Photosvstem I. a pair of electrons are raised to a higher energy level. They are captured by the primary acceptor which passes them on to ferredoxin (Fd), and plastoquinone (PQ). cytochrome complex, plasticity and (PC) and finally back to chlorophyll P₇OQ.

• The process is cyclic. At each step of electron transfer, the electrons lose potential energy. Their trip downhill is used by the transport chain to pump H⁺ across the thylakoid membrane. The proton gradient triggers ATP synthesis.
• Non-cyclic photophosphorylation. When both photosystems are illuminated, there is a continuous current of electrons flowing from water to NADP⁺. Electrons from P6g0 are replaced by electrons removed from water by splitting of water that evolves oxygen.

The excited electron from P680 flows down an electron transport chain to P700 (Pc- plastoquinone, cytochrome complex, PC-plastocyanin) generating ATP. Illumination of PSI boosts electrons to a high energy state which are passed to NADP reducing it to NADPH (protons from H₂O. The net products of non-cyclic electron flow are ATP and NADPH.

NEET Biology Photosynthesis And Translocation Of Organic Solutes Calvin Cycle

Melvin Calvin (1954), an American scientist, worked out the path of carbon by using the paper chromatography technique. In recognition of his work, Calvin was awarded with Nobel Prize in 1961. Analysis of plant extracts was made within seconds after the beginning of photosynthesis with the injection of 14CO₂.

Photosynthesis And Translocation Of Organic Solutes NEET Notes

Various steps of the dark phase can be studied as under:

• Carboxylation. The first step is the carboxylation of Ribulose, 1,5 biphosphate (RuBP) by atmospheric CO₂ in the presence of the enzyme RuBP carboxylase or rubisco.
• Six molecules of RuBP (5-carbon compound) come in contact with six molecules of CO₂ to form six molecules of six carbon unstable compounds which are converted into 12 molecules of PGA (3-carbon compound) with the help of an enzyme called carboxydisniutase.
• Rubisco is a large protein molecule and constitutes 16 per cent of chloroplast protein and is one of the most abundant proteins on the earth.
• Glycolytic reversal. The 6 molecules of PGA utilise 6 ATP molecules to form 6 molecules of 1,3- diphosphoglyceric acid. These, in turn, utilize 6 NADPH supplied by the light reactions and get converted to a 3-C glyceraldehyde phosphate- a triose phosphate (TP).
• It seems to be a reversal of glycolysis, the only difference being that the reducing power is obtained from NADPH, and not NADP.
• PGA + ATP + NADPH -» Glyceraldehyde.
  phosphate + NADP+ + ADP + IP
• Regeneration of RuBP- F-6-P next undergoes a transketola.se relation that removes, the two top carbons as the thiamine pyrophosphate (TPP) derivative,, of glycoaldehyde, leaving the tetrose erythrose 4-phosphate (E-4-P).
• The (E-4-P) condenses,s by aldolase reaction, with DHAP to form sedoheptulose diphosphate (SDP), and this is converted by a second^ energy-liberating step to sedoheptulose-7-phosphate (S-7-P) and Pi by a phosphatase reaction.
• As far as can be determined, the same phosphatase works on FDP and SDP. The S-7-P undergoes a transketolase reaction in which. the two top carbons are removed as TPP- glycolaldehyde leaving the pentose ribose-5 phosphate (Ru-5-P).
• This is converted to ribulose-5-phosphate (Ru-5-P) by phosphopento.se isomerase. The TPP-glycoaldehyde derived from F-6-P and F-7-P in the transketolase reaction is transferred to PGA forming xylulose-5-phosphate (Xu-5-P) which is converted to Ru-5-R hy n phosphopentose epimerase. The R-5-P is converted to Ru-5-P by an isomer.

NEET Biology Photosynthesis And Translocation Of Organic Solutes Factors Affecting Photosynthesis

se and is phosphorylated by phosphoribulokinase. ATP being the donor produces ribulose biphosphate (RuDP) and ADP ( a second “priming” reaction that prepares the pentose for carboxylation).

1. Light Intensity. The compensation point is 25-100 ft candles in shade plants and 100- 400 ft candles in sun plants. The optimum light intensity is 10% of full sunlight for shade plants and 50-70% of full summer sunlight for C₃ sun plants.
2. In C4 plants saturation point is not reached even in full sunlight. At higher light intensity, there is a decrease in photosynthesis called solarisation. It can be due to photoinhibition (reduction in hydration)and photoxidation.
3. Light Quality. Red light favours carbohydrate synthesis while blue light stimulates protein synthesis. Maximum photosynthesis occurs in the blue and red parts while minimum photosynthesis takes place in the green part of the spectrum.
4. Red light is more efficient in photosynthesis as compared to blue light. However, maximum photosynthesis occurs in full sunlight.
5. Oxygen. In C₃ plants, the optimum oxygen for photosynthesis is 2-5%. It is reduced at normal atmospheric concentration of oxygen. No such effect is found in C₄ plants. Above 21% there is a reduction in photosynthesis (Warburg Effect).
6. Chlorophyll. It is essential for photosynthesis. Photosynthesis does not occur in chlorotic regions. Willstatter and Stoll coined the term assimilation number or photosynthetic number as the number of CO₂ molecules reduced per unit of chlorophyll. However, chlorophyll is always supra-optimal.
7. Age. The rate of photosynthesis is maximum in just matured leaves but declines with age.
8. If the rate of translocation becomes slower than the rate of synthesis, the latter also declines due to the accumulation of end products. Chemicals like cyanides, NH^–, OH, CO, H₂S, iodoacetates, chloroform, ethers, DCMU, CMU etc. inhibit photosynthesis.
9. Accumulation of End Products. Accumulation of food in the chloroplasts reduces the rate of photosynthesis.
10. Duration. Photosynthesis can continue indefinitely in the presence of light though the rate begins to fall slightly after 3-4 days of continuous exposure.

NEET Biology Photosynthesis And Translocation Of Organic Solutes Photorespiration

Respiration that is initiated in chloroplast and occurs in light is called photorespiration.
With an increase in temperature as on a hot summer day the affinity of RuBP carboxylase for CO₂ decreases and O₂ increases.

• As a result, RuBP is changed to 2 Phosphoglycolate and PGA. Thus photosynthetically fixed carbon is lost by photorespiration.
• Photorespiration takes place through the Involvement of three cell organelles, the chloroplast, peroxisomes and mitochondria.
• Photorespiration is the process of the uptake of O₂ and the production of CO₂ in light by photosynthesising tissues. It is quite common in C₃ plants.
• Photorespiration causes a high loss of fixed carbon without producing energy-rich compounds is produced during this process.
• Photorespiration is also called a cycle because of 2-carbon intermediates.
• Linking Of Photorespiration To Calvin Cycle

1. The first oxidative slop is the conversion of Rnl)P into 3-carbo PGA and 2-Carlion phosphor glycolic acid which moves lo peroxisomes to form glyoxylic acid, and the glyoxylic acid is converted to serine. Serine passes out to the mitochondria is converted into IHIA and finally enters the Calvin cycle.

NEET Biology Photosynthesis And Translocation Of Organic Solutes C4 Pathway

In plants like maize, sorghum, sugarcane etc. the CO₂ molecule combines with IMiP to form a four-carbon compound, oxaloacetic acid (OAA). It is known as the C₂ cycle because the initial product of CO₂ fixation is a 4-carbon compound.

Overall C4 equation is
6PEP+ 6RuBP + 6CO₂  + 30ATP + 12NAPH-> 6PEP + 6RuBP + C₆ H₂ O6 + 30ADP +30 H₃ PQ₄  + 12NADP

Difference Between C3 And C4 Plants

NEET Biology Photosynthesis And Translocation Of Organic Solutes Important Terms

• Calvin Cycle. The reductive pentose pathway of photosynthesis is named after its discoverer. It is also called a pathway”.
• Hill Reaction. It is the name of a part of the light reaction of photosynthesis, after R. Hill, who first observed it in 1937, Under Hill’s reaction, NADP is reduced to NADPH₂
• Blackman’s law of limiting factors. It suggested that when a process is conditioned to its rapidity by it number of factors, keeping other factors constant, the rate of process is determined by the slowest or limiting factor.
• Reductive I’cntose Pathway. It is a set of reactions in the process of photosynthesis in which CO₂ is fixed by ribulose-diphosphate ( a pentose sugar) to give PGA, which is used to produce a hexose sugar and more ribulose-diphosphate, which is used for further CO₂ fixation.
• Sedohcpliilo.se. A seven-carbon compound formed in the Calvin cycle.
• C3 Pathway. It is another name for the Colvin cycle which is also called the reductive pentose pathway.
• C4 Pathway. It is a kind of CO₂ fixation, found in some tropical plants-both monocotyledons and dicotyledons. It is also called the Hatch and Slack cycle.
• In this pathway, CO₂ is fixed by a three-carbon compound (phosphoenol pyruvate) and ultimately a molecule with 4 carbon atoms (male) is produced.
• Plants, in which the C₄ pathway is found, are called C₄ plants, For Example. Saccharum, Sorghum, Maize, Cyperus etc.
• Photorespiration is absent in C4 plants. These plants use CO₂ more efficiently than C₃ plants.
• Crassulacean Acid Metabolism (CAM). It is a kind of CO₂ fixation found in many succulent plants, For Example. Crassulaceae.
• Phosphoglyceric Acid (PGA). It is a compound with three atoms of carbon. It is the first product of the reaction between CO₂ and ribulose diphosphate in the reductive pentose pathway of the process of photosynthesis.
• Ribulose diphosphate. A compound made up of a molecule of the pentose sugar ribulose and two phosphate groups. It is also called ribulose 1,5-diphosphate or RuDP. It is the main compound involved in CO₂ fixation.
• Red drop. Sharp fall in the rate of photosynthesis as found by Emerson near the far end of the spectrum, This decline in photosynthesis is called the red drop.
• Spectrophotometer. An instrument used to measure the rate of absorption of different wavelengths of light by different pigments. The absorption of different wavelengths of light by a particular pigment is plotted and called the absorption spectrum.

NEET Biology Photosynthesis And Translocation Of Organic Solutes

1. The food is translocated from the supply end or source (leaves) to the consumption end or sink (storage regions).
2. The translocation of organic solutes takes place in plants in all directions.

• • Downward translocation (from leaf to stem and roots)
  • Upward translocation (from leaves to developing buds)
  • Radial translocation (from the pith to the cortex).

1. There is ample evidence to believe that food is translocated through phloem such as
   its component structure, the effect of blocking phloem and ringing experiments conducted by Malpighin Stephan Hales and Curtis.
2. The experimental evidence collected by Rabadieu and Burr by using C₁₄ and experiments-with aphids performed by Kennedy and Mittler also confirms phloem translocation of food. Some days may be translocated in an upward direction through the xylem.
3. Radioactive isotopes such as P₃₂, S₃₅, Sr₉₀, N₁₅, C₁₄, C₁₁ and H₃ have been used in recent years along with techniques like a reverse flap, autoradiography and freeze-drying.
4. Food is translocated mainly as sucrose but also in the form of raffinose, stachyose, verbascose, mannitol, myoinositol and sorbitol.
5. The rate of metabolite movement is calculated in terms of mass transfer rate. The translocation velocity may be 55 cm/hr (sucrose). It is 270 cm/hr in sugarcane and 290 cm/ hr in squash.
6. Mechanism of Translocation. Several hypotheses have been proposed to explain the mechanism of translocation.

• It was earlier believed that good is translocated from source to sink by simple diffusion. Since the rate of diffusion is extremely slow hence Mason and Phillips proposed an activated diflusion hypothesis which lacked experimental evidence.
• De Vries proposed that food is translocated by streaming currents of protoplasm.
• It explains the bidirectional movement of metabolites and the faster rate of translocation. observe the streaming of protoplasm in mature sieve elements.
• Thaine and Canny observed streaming in vertically running transcellular strands in sieve elements. The presence of these strands has been confirmed by the use of C₂ But the die rate of translocation as last as 290 cm/hr cannot be achieved by protoplasmic streaming.
• The activated diffusion theory of Mason and Maskell (1936) takes into account the utilization of ATP.

1. Electro-osmotic theory was proposed by Fensom (1957) and Spanner (1958). According to this, an electropotential across the sieve plate is responsible for a faster rate of liquid flow.
2. Munch’s Mass Flow or Pressure Flow Hypothesis (1930) Munch’s hypothesis postulated the movement of protoplasm mass along a turgor pressure gradient induced by the maintained gradient of water potential.
3. This is based on the principle that an increase in turgor pressure causes mass flow’ of solution from production chamber A (comparable to leaf) to consumption chamber (comparable to root).
4. The movement of solute will continue till the solutions in both chambers attain the same concentration.
5. In living plants, the carbohydrates are continuously synthesized in mesophyll cells and are translocated to roots or storage organs through phloem.

NEET Biology Photosynthesis And Translocation Of Organic Solutes Factors Affecting Translocation

The process of food translocation is influenced by several factors as follows :

• Temperature: The effect of temperature may be direct or indirect. It has been experimentally confirmed that the optimum temperature for translocation ranges between 20 -30 C. It increases with the increase of temperature up to a maximum limit and then decreases.
• By using C14 it has been observed that the translocation rate increases in sugarcane when temperature is raised from 20 to 33 C. It has been also observed that when the root temperature is higher than the shoot, translocation to the root increases but to the shoot tip, decreases.
• If the condition is reversed i.e. when the shoot temperature is higher than the roots, translocation to the shoot tip increases and to the roots decreases.
• Light: The rate of translocation is influenced by light intensity. With the increase in light intensity the translocation to root as compared to shoot increases. However, by using C*  it has been observed that in the dark, more food is translocated in the root of Glycine than in light.
• Minerals: It has been demonstrated that boron enhances the translocation of labelled sucrose in tomatoes. It is thought that boron makes a complex with sucrose. This borate sugar moves more rapidly than non-borate sugar. Phosphorus deficiency also reduces the translocation rate.
• Hormones: It is well known that cytokinins influence the translocation of soluble nitrogen
• compounds. When they have sprayed the leaves externally, translocation of N^–, t compounds from lamina to petiole is retarded,’ hence it remains green for a longer period.
• Inhibitors: The metabolic inhibitors like azides, CP, 2-4 dinitrophenol (DNP), fluorides, HCN, iodoacetates etc. retard metabolism and thus indirectly influence the translocation process.

Photosynthesis is the single most important biological process required for human existence.

• Jan Baptism Van Uelmont (Belgian physician) with his simple experiments concluded that all the substance of plant was produced from water and none from soil Contribution of Jan Ingcnhonsz. He confirmed Priestley’s work and also discovered that the release of O, by plants was possible only in sunlight by green plants.
• Contribution of C.B. Van Nicl. He gave a simplified equation of photosynthesis.
• Contribution of Joseph Priestley (1703-1804). He showed that plants can take up CO₂ from the atmosphere and release O₂
• Within the leaf, photosynthesis occurs in specialised cells called mesophyll cells.
• PAR is photosynthetically active radiation of visible speed
• ATP, NADPH + H⁺ are produced in light reaction and are used for the reduction of CO₂ Isolated chloroplast cannot carry out CO₂ reduction because enzymes necessary for CO₂ reduction are leached out during the isolation of chloroplasts.
• Chlorophyll acts as a reaction centre and accessory pigments called carotenoids act as antenna complexes and harvest light from different regions of the spectrum.

Photosynthesis And Translocation Of Organic Solutes NEET Notes

Crassulaccan Acid Metabolism (Cam Plants)

CAM plants fix CO₂ at night, from malice which is stored in large vacuoles in mesophyll cells until the next day. CAM plants use the enzyme Pepco (PEP carboxylase). The malate formed at night releases CO₂ during the day to the Calvin cycle within the same cell, which now has NADPH and ATP available from light-dependent reactions.

• CAM represents Crassulacean acid metabolism. The Crassulaceae is a family of flowering succulents. In CAM plants stomata open during night only and is an adaptation of xerophytic succulents. Photosynthesis in such cases is usually not as efficient as in C₃ or C₄ plants, but it allows the CAM plants to live under stress-
• Isolated chloroplasts can carry out CO₂ reduction provided the leached substances are externally supplied to them.
• This was proved by D.I. Arnon and his associates.
• Dark reactions can occur in light as well as in the dark.
• The temperature coefficient (Q₁₀) is defined as the ratio of the velocity of a reaction, at a particular temperature to that at a temperature 10°C lower.
• For a physical process, the value of Q₁₀ is slightly greater than one.
• For photochemical reactions, the value of Q10 is one.
• For a chemical reaction, the value of Q₁₀ is two or more i.e., with the rise of 10°C temperature, the rate of chemical reaction is doubled.
• The difference between C₄ plants and CAM plants is that in C₄ plants two cycles are separated by different leaf cells (i.e. in mesophyll cells and bundle sheath cells) whereas in CAM plants both pathways are found in mesophyll cells both being separated by time.

NEET Biology Photosynthesis And Translocation Of Organic Solutes Quanta to Memory

Chi C—C₃₅ H₃₂ O₅ N₄ Mg (Mol. wt.) = 712. Phytol absent it is present in brown algae + diatoms.

Chl d—C₅₄ H₇₀ O₆_ N₄ Mg (Mol. wt. 895) red algae

Bacteriochlorophyll a—C₅₅ H74 O₆ N₄ Mg (Mol. wt. 911)

• Chi a : Chi b = 2.5-3.5 : 1
  For sun plant 5.5: 1 [For heliophyte)
  For shade plant 1:4:1 [For sciophyte]
• Chlorophyll absorbs more of blue light than red light. 40% (Blue) 30% (Red) For Chi a 48% (Blue) 20% (Red) —For Chi b
• Bacteriochlorophyll-b found in Rhodopseudomonas is not yet known.
• Chlorobium Chlorophyll-old name of bacterioviridin
• Carotenoid-lipochrome. Fat-soluble, light not necessary.
• Calvin gave a molecular model of the chloroplast.
• Discovered by Wakineroder as a provitamin of carrot types – a, b, g and carotene, phytotene, neurosphere.

Ratio of xanthophyll: Carotene in plant 2:1.

• Xanthophyll Zeaxanthin gives a yellow colour to the leaf.
• Size of chlorophyll 15 A ‘ 15 A Porphyrin head while Phytol tail is 20 A long
• Chlorophyll absorbs light of wavelength 400-500 nm and 600-700 nm.
• During peak hour, the rate of photosynthesis is 20 times of respiration.
• C₄ plants-Dimorphism grain mesophyll, e.g. sugarcane.
• Temp, range for algae; 75 C.
• C₃ plant; 10-25°C, C4 plant-; 30°C-45°C.
• Solute translocated contains mostly 10-26% carbohydrates sucrose and 10% nitrogen compound.
• If CO₂ increases by 15-20 times then photosynthesis increases if no other factor is limiting.
• If the CO₂ cone decreases by 10-15 times, the rate of Photosynthesis decreases.
• The total amount of solar energy trapped by photoautotrophs is 0.024 % and the product, of photosynthesis, is 170 billion tonnes from 8 “108-metre tonne of carbon

NADP is called TPN (Triphosphopyridine nucleotide called Co II.

• The excited state remains for 5×1 O’9 sec.
• Coupling factors are present on the thylakoid.
• Bacterial Photosynthesis-Green Sulphur (e.g. chlorobium), Purple sulphur (Eg. Chromatium, Purple non-Sulphur (Rhodo Sperellum)
• In cyclic photophosphorylation, e“ released by the reaction centre is accepted by the reaction centre.
• The process of photophosphorylation is the same as mitochondrial reaction is called Oxidative phosphorylation.
• All types of plastid processes are the same as they can transform a frame from one form to another.
• Ratusky effect Chi shows out burst of fluorescence during the first few moments of illumination.
• C₃ and C₄ plants may occur in different species but the same genus For Example- Euphorbia corollata, E. macula
• In grass allotropes, semialata in the C₃ plant and C₄ plant occur in another ecotype.
• Photo-bioluminescence. The phenomenon of re-irradiation of absorbed energy. It consists of fluorescence which occurs almost instantaneously and phosphorencence occurs after a gap. Chlorophyll shows fluorescence. Their phosphorescence is doubtful.
• Carotenoids absorb light strongly in the blue-violet range. These are called shield pigments as they protect chlorophyll from photooxidation, (bleaching)
• Park and Biggins coined the term ‘Quantosomes’ for a group of pigment molecules required for carrying out a photochemical reaction. These occur in membranes of thylakoids. Each quantosome has 250-300 chlorophyll, carotenoids, quinone compounds, sulpholipids, phospholipids, protein and chlorophyll molecules-160 chi a, 70 chi b, 50 carotenoids.

1. Chlorophyll transfers solar energy to reaction centres by resonance transfer or inductive resonance.
2. Of the 90% of photosynthesis carried out by algae, 80% is carried out by marine and 10% by freshwater algae.
3. Photosynthetic efficiency increases in intermittent light.
4. The products of the light phase are not used immediately in the dark phase, so photosynthetic efficiency decreases in continuous saturating light.
5. RuBP carboxylase or Rubisco is a large protein molecule and constitutes about 16% of chloroplast protein. It is the most abundant protein on the earth.
6. O₂ is a competitive inhibitor of CO₂ fixation. Any increase in the O₂ cone, would favour the uptake of O₂ rather than CO₂ and thus inhibit photosynthesis.
7. Photorespiration is also called dark respiration and there is a loss of Carbon as CO, and a loss of energy in this process.
8. Photorespiration reduces the potential yield of plants growing in the tropics by 30-40%.
9. H.P. Kartschak and C.E. Hartt found that in sugarcane, a tropical plant, leaves removed CO, more efficiently from the atmosphere and the first products of photosynthesis were acids having 4-C atoms (Malic, OAA, aspartic acid) than 3 Carbon*acid PGA.
10. The same has been found true for tropical plants including monocots (Maize, Sorghum and Eleusine) and dicots (Amaranthus and Euphorbia spp.)
11. Chloroplasts in C₄ plants are called dimorphic.
12. Correlation between Kranz anatomy and C₄ plants was established by Dewton and Treguna.

• 2.5-30° C is the optimum temperature for photosynthesis In opuntia it can be 55 C.
• In lichens -20° C to -24° C and in conifers -35° C.
• Total sugar in phloem sap can be up to 90%. Sucrose constitutes 5-15% of total sugars. Other sugars are raffinose (triose), stachyose (tetrose) and verbascose (pentose)
• Pure phloem saps may be collected by using sap-sucking aphids.
• Photosynthesis is an anabolic, endergonic, oxidation-reduction process.
• Solarisation-Destruction of chlorophyll due to high light intensity.
• The most common limiting factor for photosynthesis is CO,
• Compensation point- light intensity at which rate of photosynthesis = rate of respiration (In morning and evening)
• In C₃, more CO is released in light than in dark (due to photorespiration)
• The yield of C₃ plants is increased by increasing CO, in the atmosphere.
• Tracer Technique-Rabideau and Buer supplied C₁₄ O₂ to a leaf during photosynthesis. The sugar synthesised in this leaf was labelled with 14C (tracer). The presence of labelled sugars in the phloem showed that solutes are translocated through the phloem.
• Goodwin suggested that Chlorophyll and Carotenoids may be attached to the same protein forming a complex called photosynthin.
• Phycobilins are also known as biliproteins
• O₂ of glucose comes from CO₂ •

Out of total light, 1-2% light is used by green plants.

Enzyme PEP Carboxy dismutase in C₄ plants is very sensitive to CO₂, this is why C₄ plants can absorb CO, from its low concentration while C₃ plants fail to avail it from such a low concentration.

The first step of photosynthesis is the excitement of electrons of the chlorophyll molecule.

• The first chemical step of photosynthesis is the photolysis of H₂
• The light reaction forms ATP or assimilatory power and NADPH2 which is used in the reduction of CO, in the dark phase.
• Light reaction occurs in the granum and dark reaction in the stroma.
• Phosphoglyceraldehyde-it is the connecting link between photosynthesis and respiration.
• During solarization, photooxidation occurs in which some cell constituents are oxidized.
• Light is never a limiting factor except on cloudy days.
• Photosynthesis occurs between 390-750 m.u.
• Assimilatory Number-It is the amount of CO₂ absorbed in gms/hour by gm of chlorophyll.
• 48 light quantum is necessary for 6 CO₂
• Bacteria photosynthesise at 900 mu wavelength
• Plastidome-Plastid complex of cell.

Quantum yield- No. of O₂ released per photon or quantum of light. Its value is 1/8 —1/10. In other words, the evolution of one molecule of O₂ or consumption of one molecule of CO₂ requires 8-10 quanta.

NEET Biology Photosynthesis And Translocation Of Organic Solutes Questions From Competitive Examinations

Question 1. Which of the following occurs in the dark reaction of photosynthesis?

1. Formation of ATP
2. Release of O₂
3. Release of H,
4. Synthesis of PGAL.

Answer: 4. Synthesis of PGAL.

Question 2. The first reaction in photosynthesis is :

1. Photolysis of water
2. Excitation of chlorophyll molecules
3. Formation of ATP
4. Fixation of CO₂.

Answer: 2. Excitation of chlorophyll molecules

Question 3. Fixing one molecule of C02 in the Calvin cycle is required :

1. 3 ATP + 1 NADPH
2. 3 ATP + 2 NADPH₂
3. 2 ATP + 3 NADPH₂
4. 3 ATP + 3 NADPH

Answer: 2. 3 ATP + 2 NADPH₂

Question 4. The enzyme required in early C02 fixation in the C4 cycle is :

1. RuBP carboxylase
2. RuBP oxygenase
3. PEP carboxylase
4. PGA dehydrogenase.

Answer: 2. RuBP oxygenase

Question 5. A chemical which absorbs light energy and changes it to chemical energy is :

1. Xanthophyll
2. Chlorophyll a
3. Chlorophyll b
4. Chlorophyll c.

Answer: 2. Chlorophyll a

Question 6. One of the following is a C4 plant:

1. Sugarcane
2. Tomato
3. Mango
4. Apple.

Answer: 1. Sugarcane

Question 7. Which pair is wrong?

1. C₃ – maize
2. C₄ – kranz anatomy
3. Calvin cycle – PGA
4. Hatch and Slack cycle

Answer: 1. C₃ – maize

Question 8. Which pigment system is inactivated in the red drop :

1. PS-1 and P.S-II
2. PS-I
3. PS-II
4. None.

Answer: 3. PS-II

Question 9. Which plant is LDP :

1. Tobacco
2. Glycine max
3. Mirabilis Jalapa
4. Spinach.

Answer: 4. Spinach. Spinach.

Question 10. The proteinaceous pigment which controls the activities concerned with light is :

1. Phytochrome
2. Chlorophyll
3. Anthocyanin
4. Carotenoids.

Answer: 1. Phytochrome

Question 11. The first stable product of photosynthesis in C4 plants is :

1. Ribulose a 5 – biphosphate
2. Phosphoglyceric acid
3. Malic acid
4. PGAL.

Answer: 3. Malic acid

Question 12. Which one of the following is the aim of Moll’s half¬leaf experiment?

1. To show that carbon dioxide is produced during aerobic respiration
2. To show that carbon dioxide is produced during anaerobic respiration
3. To show Chlorophyll is necessary for photosynthesis
4. To show the importance of carbon dioxide for photosynthesis.

Answer: 4. To show the importance of carbon dioxide for photosynthesis

Question 13. Photosynthesis is maximum in :

1. Blue light
2. Greenlight
3. Red light
4. U.V. light.

Answer: 3. Red light

Question 14. Cyclic photophosphorylation form :

1. ATP
2. ATP and NADPH
3. NADPH
4. ATP, NADPH and O.

Answer: 1. ATP

Question 15. Which of the following possess both PS -1 and PS – II?

1. Purple sulphur bacteria
2. Green sulphur bacteria
3. Cyanobacteria
4. Purple non-sulphur bacteria.

Answer: 3. Cyanobacteria

Question 16. Evidence for liberation of 0, from water during photosynthesis comes from :

1. Release of O₈₀ if the water contains the same
2. Isolated chloroplast supplied with reducing agents like potassium ferrocyanide evolves O₂ even in
   absence of CO₂
3. Photosynthetic bacteria do not liberate O₂ and they use H, and S to obtain reduced power
4. All the above.

Answer: 4. All the above.

Question 17. Which of the following provides energy to ETS by absorption of sunlight?

1. Water
2. Chlorophyll
3. Mitochondria
4. ATP.

Answer: 4. ATP.

Question 18. Photosystem II occurs in :

1. The outer membrane of mitochondria
2. Grana
3. Stroma
4. The inner membrane of mitochondria.

Answer: 2. Grana

Question 19. CO, acceptor in the C₃ cycle is:

1. PEG
2. RuBP
3. OAK
4. Malic acid.

Answer: 2. RuBP

Question 20. ETS associated with photophosphorylation occurs in :

1. Stroma
2. Thylakoid
3. The outer membrane of the chloroplast
4. Mitochondria.

Answer: 4. Mitochondria.

Question 21. C₄ plants are abundant in :

1. Tropical regions with more dry conditions
2. Tropical regions with more humid conditions
3. Temperate region with more dry conditions
4. Temperate regions with more humid conditions.

Answer: 2. Tropical region with more humid conditions

Question 22. Photorespiration in C, plants stall from :

1. Phosphoglycerate
2. Phosphoglycolate
3. Glycerate
4. Glycine.

Answer: 2. Phosphoglycolate

Question 23. Hill reaction occurs in :

1. High altitude plant
2. Total darkness
3. Absence of water
4. Presence of ferricyanide.

Answer: 4. Presence of ferricyanide

Question 24. In sugarcane plants 14CO₂ is fixed in malic acid, in which the enzyme that fixes C02 is :

1. Fructose phosphatase
2. Ribulose biphosphate carboxylase
3. Phosphoenol pyruvic acid carboxylase
4. Ribulose phosphate kinase.

Answer: 3. phosphoenol pyruvic acid carboxylase

Question 25. Which of the following is not an electron carrier?

1. CoQ
2. Cytc
3. Cyt a
4. H₂ O           
5. Cyt a3

Answer: 4. H₂O

Question 26. How many molecules of glycine are required to release one molecule of CO₂  during photorespiration?

1. Four
2. Three
3. Two
4. One.

Answer: 3. Two

Question 27. Who demonstrated photolysis of water by isolated chloroplasts?

1. Liebig
2. M. Calvin
3. Von Neil
4. Hill.

Answer: 4. Hill.

Question 28. As compared to sun plants, plants adapted to low light intensity possess :

1. Spiny leaves
2. Extensive root system
3. High rate of CO₂  fixation
4. Larger photosynthetic unit.

Answer: 4. Larger photosynthetic unit.

Question 29. In comparison to a C₃ -plant, how many additional molecules of ATP are needed for the net production of one molecule of hexose sugar by C₄ -plants :

1. Six
2. Two
3. Zero
4. Twelve.

Answer: 4. Twelve.

Question 30. Photosynthesis in C4 plants is relatively less limited by atmospheric C02 levels because

1. Effective pumping of CO₂  into bundle sheath cells
2. The primary fixation of CO₂  is mediated via PEP carboxylase
3. Four carbon acids are the primary initial CO₂  fixation products
4. Rubisco in C₄  plants has a higher affinity for CO₂.

Answer: 2. The primary fixation of CO₂  is mediated via PEP carboxylase

Question 31. Photosynthetic active radiation (PAR) has the following range of wavelengths :

1. 400-700 nm
2. 450-950 nm
3. 340-450 nm
4. 500-600 nm.

Answer: 1. 400-700 nm

Question 32. The pathway of the Calvin cycle was discovered by using an isotope of:

1. 180
2. 32P
3. UC
4. I4C.

Answer: 4. I4C.

Question 33. Chloroplast lacks :

1. Carotene
2. Chlorophyll
3. Xanthophyll
4. Anthocyanin.

Answer: 4. Anthocyanin.

Question 34. Bacterial photosynthesis does not show :

1. Photosystem I
2. Utilization of energy
3. Evolution of oxygen
4. Formation of organic product.

Answer: 4. Formation of organic product

Question 35. A phenomenon which converts light energy into chemical energy is:

1. Respiration
2. Photosynthesis
3. Transpiration
4. None of these.

Answer: 2. Photosynthesis

Question 36. In photosystem-I, the first electron acceptor is :

1. Plastocyanin
2. An iron-sulphur protein
3. Cytochrome
4. Ferredoxin.

Answer: 2. An iron-sulphur protein

Question 37. The translocation of organic solutes in sieve tube members is supported by:

1. Mass flow involving a carrier and ATP
2. Cytoplasmic streaming
3. Root pressure and transpiration pull
4. P-proteins.

Answer: 4. P-proteins

Question 38. During photorespiration, the oxygen-consuming reaction (s) occur in :

1. grana of chloroplasts and peroxisomes
2. stroma of chloroplasts
3. stroma of chloroplasts and mitochondria
4. stroma of chloroplasts and peroxisomes.

Answer: 3. stroma of chloroplasts and mitochondria

Question 39. The Calvin cycle proceeds in three stages.

Reduction, during which carbohydrate is formed at the expense of the photochemically made ATP and NADPH

Regeneration, during which the carbon dioxide acceptor ribulose-1, 5-biphosphate is formed

Carboxylation, during which carbon dioxide combines with ribulose-1, 5-biphosphate.

Identify the correct sequence.

1. 3-1-2
2. 3-2 – 1
3. l-2-3
4. 2 – 1 – 3
5. 1-3-2.

Answer: 1. 3-1-2

Question 40. Which of the following is a simplified equation of photosynthesis?

Answer: 4.

Question 41. Choose the correct combination of labelling the number of carbon compounds in the substrate molecules, involved in the citric acid cycle.

1. A. 4C, B. 6C, C. 5C, D. 4C, E. 4C
2. A. 6C, B. 5C, C. 4C, D. 3C, E. 2C
3. A. 4C, B. 3C, C. 4C, D. 5C, E. 6C
4. A. 4C, B. 5C, C. 6C, D. 4C, E. 4C
5. A. 4C, B. 6C, C.4C, D. 4C, E. 4C.

Answer: 1. A. 4C, B. 6C, C. 5C, D. 4C, E. 4C

Question 42. In the given chart of photophosphorylation, what does “a” represent?

1. PC
2. FRS
3. PQ
4. Cyt. a3.

Answer: 3. PQ

Question 43. The reaction that is responsible for the primary fixation of CO₂  is catalysed by:

1. RuBP carboxylase
2. PEP Carboxylase
3. RuBP carboxylase and PEP
4. PGA synthetase

Answer: 3. RuBP carboxylase and PEP

Question 44. The enzyme that is not found in the C₃  plant is :

1. RuBP carboxylase
2. NAJDP reductase
3. ATP synthase
4. PEP carboxylase

Answer: 4. PEP carboxylase

Question 45. Which of the following three organelles are involved in photorespiration?

1. Chloroplast, mitochondrion, glyoxysome
2. Chloroplast, peroxisome, mitochondrion
3. Chloroplast, glyoxysome, mitochondrion.
4. Chloroplast, lysosome, peroxisome

Answer: 2. Chloroplast, peroxisome, mitochondrion

Question 46. Consider the following statements :

A. The portion of the spectrum between 500 nm and 800 nm is also referred to as photosynthetically active radiation (PAR)

B. Magnesium, calcium and chloride ions play prominent roles in the photolysis of water

C. In cyclic photophosphorylation. oxygen is not released (as there is no photolysis of water)  and NADPH is also not produced.

D. Of these statements given above

1. A is true, but B and C are false
2. A and B are false, but C is true
3. B is true, but A and C are false
4. A and B are true, but C is false
5. A and C are true, but B is false

Answer: 2. A and B are false; but C is true

Question 47. Which of the following statements about photosynthesis is/are correct?

A. In C₄  plants, the primary CO₂  acceptor is PEP

B. In the photosynthetic process PS II absorbs energy at or just below 680 nm

C. The pigment that is present in the pigment system 1 is P683 :

1. B and C only
2. An only
3. C only
4. A and B only
5. A and C only.

Answer: 4. A and C only.

Question 48. Consider the following statements regarding photosynthesis :

A. ATP formation during photosynthesis is termed as photophosphorylation

B. Kranz’s anatomy pertains to leaf

C. Reduction of NADP+ to NADPH occurs during the Calvin cycle

D. In a chlorophyll molecule magnesium is present in phytol til. Of the above statements :

1. A and B are correct
2. C and D are correct
3. A and C are correct
4. A and D are correct
5. B and C are correct.

Answer: 1. A and B are correct

Question. 49. Which of the following statements is/are not true?

A. In CAM plants stomata open during the dark and remain closed during the day

B. Role of Na+ in stomatal opening is now universally accepted

C. The water of root cells is higher than the water potential of soil

D. Capillarity theory is the most accepted theory of water movement through plants

E. The walls of xylem vessels made up of lignocellulose have a strong affinity for water molecules

1. B, C and E only
2. B, C and D only
3. A, B and C only
4. B, and only
5. A and E only.

Answer: 2. B, C and D only

Question 50. Which of the following is photophosphorylation?

1. production of ATP from ADP
2. production of NADP
3. synthesis of ADP from ATP
4. production of PGA.

Answer: 1. production of ATP from ADP

Question 51. In leaves of C₄  plants, malic acid synthesis during CO, fixation occurs in the:

1. bundle sheath
2. guard cells
3. epidermal cells
4. mesophyll calls.

Answer: 4. mesophyll calls.

Question 52. Electrons from exited chlorophyll molecule of photosystem II are accepted first by :

1. quinone
2. ferredoxin
3. cytochrome -b
4. cytochrome -i

Answer: 1. quinone

Question 53. The C₄  plants are photosynthetically more efficient than C₃  plants because:

1. the CO, efflux is not prevented
2. they have more chloroplasts
3. the CO, compensation point is more
4. CO, generated during photorespiration is trapped and recycled through PEP carboxylase.

Answer : 3. the CO, compensation point is more

Question 54. CAM helps the plants in :

1. Conserving water
2. Secondary growth
3. Disease resistance
4. Reproduction.

Answer: 1. Conserving water

Question 55. A process that makes an important difference between C₃ and C₄  plants is :

1. Glycolysis
2. Photosynthesis
3. Photorespiration
4. Transpiration.

Answer : 3. Photorespiration

Question 56. Which of the following concerning early experiments of photosynthesis is wrongly matched?

1. (A) Joseph Priestley  – Showed that plants release
2. Jan Ingenhousz    – Showed that sunlight is essential for photosynthesis
3. Julius von Sachs  – Proved that plants produce glucose when they grow
4. T.W. Engelmann    – Showed that the green substance is located within special bodies in plants
5. Cornelius van Niel – Showed that hydrogen reduces CO, to carbohydrates.

Answer: 5. Cornelius van Niel – Showed that hydrogen reduces CO, to carbohydrates

Question 57. Which of the following statements regarding the C4 pathway is false?

1. The primary CO, acceptor is phosphoenol pyruvate.
2. The enzyme responsible for CO, fixation is PEPcase.
3. The mesophyll cells lack RuBisCO enzyme.
4. The C4 acid OAA is formed in the mesophyll cells.
5. The bundle sheath cells contain the enzyme PEPcarboxylase.

Answer: 5. The bundle sheath cells contain the enzyme PEPcarboxylase

Question 58. Consider the following statements concerning photosynthesis.

A. The first carbon dioxide acceptor in the C₄  cycle is PGA.

B. In C₃  plants, the first stable product of photo-synthesis during dark reaction is RuBP.

C. Cyclic photophosphorylation results in the formation of ATP.

D. Oxygen which is liberated during photosynthesis comes from water. Of the above statements

1. A and B alone are correct
2. A and C alone are correct
3. C and D alone are correct
4. B and C alone are correct
5. B and D alone are correct

Answer : 3. C and D alone are correct

Question 59.  The diagram represents the Hatch and Slack pathways. Choose the correct combination of labelling numbered 1 to 5.

1. 1-Mesophyll cell ; 2-Bundle sheath cell;
   3-Regeneration; 4-Fixation; 5-Decarboxylation.
2. 1-Bundle sheath cell; 2-Mesophyll cell; 3-Fixation;
   4- Regeneration; 5-Decarboxylation.
3. 1-Mesophyll cell; 2-Bundle sheath cell; 3-Decarboxylation; 4-Fixation; 5-Regeneration.
   B1 The enzyme responsible for CO, fixation is PEPcase.
4. 1-Mesophyll cell; 2-Bundle sheath cell; 3- Fixation;
   4-Decarboxylation; 5-Regeneration.

Answer: 4. 1-Mesophyll cell; 2-Bundle sheath cell; 3- Fixation; 4-Decarboxylation; 5-Regeneration.

NEET Biology Pteridophyta

• Pteridophytes. The term Pteridophyta was coined by Haeckel. Pteron (Gk) means a feather and the name Pteridophyta was given to this group because of their pinnate or feather-like fronds. Pteridophytes include about 10,000 species.
• Ferns are a big group of pteridophyta with 9300 species and some ferns may be 18 metres in height (Giant tree fern).
• The smallest pteridophyte is Azolla (aquatic fern)

Read and Learn More NEET Biology Notes

Habitats of pteridophytes

Pteridophyta NEET Notes

Features of pteridophytes

1. Pteridophytes are assemblages of seedless vascular plants that have successfully invaded the land and reproduce through spores.
2. Main plant body is sporophyte (2N).
3. initiated into root, rhizome, and leaves. The latter may be megaphyllous or microphyllous.
4. Plants show evolution of stele from protostele siphonostelesolenostele dictyostele dictyostele.
5. Spores are produced in sporangia after meiosis. A group of sporangia occurs in the form of sorus covered with indusium. They may be homosporous (For example ferns) or heterosporous (For example Selaginella).
6. Gametophytic Generation. Spores on germination form prothallus which is monoecious, bear both antheridia and archegonia.
7. Sperms and eggs on fertilization form oospores which again start sporophytic generation
8. The life cycle of Pteridophytes is of Diplohaplontic type i.e. main plant body is sporophyte which alternates with gametophyte. Both generations are morphologically dissimilar. This is also called a heterologous type of alternation of generations.

NEET Biology Pteridophyta Selaginella

The sporophytic generation of this lycopod has a plant body differentiated into genuine roots, stems, and leaves. The branched stem is typically horizontal and prostrate.

• Rhizophores extend vertically downward from the branches of the dichotomies. Adventitious roots form when the rhizosphere contacts the soil. The leaves may be uniform or potentially dimorphic.
• They possess microphyllous and ligulate characteristics. The sporophyte generates spores. Selaginella exhibits heterospory.
• Spores are generated in sporangia located in the axil of the sporophylls. The sporophylls are clustered at the terminal sections of the branches, forming the strobili.
• Each strobilus possesses microsporophylls and megasporophylls that are analogous and ligulate.
• The microsporophylls support the microsporangia, while the megasporophylls support the megasporangia.
• Each microsporangium and megasporangium possesses a bilayered jacket surrounding a nutritive tissue, the tapetum, which encases the spore mother cells. The majority of microspore mother cells undergo meiosis to produce many microspores.
• In the megasporangium, typically only one megaspore mother cell remains functional (sometimes 2-3), and after meiosis, it creates four megaspores, of which commonly one to three are nonfunctional. In S. motorsport, only a single megaspore is operational.

Pteridophyta NEET Study Material

• The developing spores are provided with nourishment by the remaining megaspore mother cells that endure degeneration
• The megasporangium assumes a lobed aspect as a consequence of the megaspores’ expansion. The spores are expelled through the dehiscence of the wall, which is divided into two halves by a vertical apical incision.
• The gametophytes. The spores are the initial cells of the gametophytic generation. The gametophyte’s growth is precocious and begins in the sporangia.

Modifications of siphonostctc

1. Cladosiphonic siphonostele. A siphonostele not perforated by leaf gaps Example a few species of Selaginella.
2. Phyllosiphonic siphonostele. A siphonostele perforated by leaf gaps- Example Nephrolepis.
3. Solenostele. A siphonostele perforated by leaf gaps which are scattered but not overlapping Example Ferns.
4. Dictyostele. A siphonostele perforated by several overlapping leaf gaps. Each separate strand is called a meri stele Example Dryopteris, Pteridium, Pteris, etc.
5. Polycyclic dictyostele. A dictyostele consisting of two or more concentric rings of meristeles Example Pteridium aquilinum.
6. Eustele. Much dissected siphonostele having vascular strands separated apart by parenchyma Example Equisetum.
7. Polysetelic condition. Presence of more than one stele Example Selaginella kraussiana.

The microspores are orange-red, tetrahedral, with a two-layered wall and tri-radiate.

Their nucleus divides by mitosis to form male gametophytes within their wall. Their liberation is generally withheld upto the 13-celled stage.

At this stage, they contain 1 urothelial cell, 8 jacket cells, and 4 androgenic cells. The four androgenic cells divide to form the antherozoid mother cells and astrocytes and ultimately 256 antherozoids are formed.

Each antherozoid is biciliate and liberated by the rupturing of the exine. They swim about freely in search of a female gametophyte or if developed within the sporangium they may be carried along with the raindrops.

The megaspores are large, white to pale green, tetrahedral, and tri-radiate.

They may be shed before any trace of a cellular organization or shortly after the first archegonia are formed or may be retained until after fertilization and a considerable development of the embryo.

The germinating megaspore enlarges considerably followed by free-nuclear division eventually giving rise to a massive multicellular megagametophyte or female gametophyte tissue. A part of the tissue of the gametophyte gets exposed.

The exposed region may contain chlorophyll and even rhizoids. Several archegonia develop from the superficial cells of this tissue along with clusters of rhizoids.

The mature archegonia have a neck of two tiers of cells each, enclosing a neck canal cell and venter enclosing a ventral canal cell and an egg. At maturity, the neck and venter canal cells disintegrate exposing the egg to be fertilized.

Pteridophyta NEET Biology Notes

Fertilization of the egg by the antherozoids results in the formation of the zygote or oospore.

Apogamy and parthenogenesis are known in several species.

The young Sporophyte. Following fertilization, the resulting zygote secretes a wall and divides and redivides to form the embryo. The embryo pushes its way into the tissues of the gametophyte by its suspensor.

It is differentiated into a stem apex, two leaf primordia with their ligules at one end, and the rhizosphere at the opposite end. Situated between them is the foot. This juvenile sporophyte ultimately matures into a sporophyte of Selaginella.

NEET Biology Pteridophyta Life Cycle Of Dryopteris

It belongs to the division Pteropsida, Class Filicineae, order Filicales, and family Polypodiaceae.

The plant body is sporophytic and the mature sporophyte contains roots, rhizomes, and leaves.

Roots are adventitious. The rhizome is well-branched and remains covered with several fine hairs called ramenta. Leaves are circinately coiled, when young. Mature leaves are very large and bipinnately compound.

Internally, the roots are ditch and exarch.

1. Internally, the rhizome contains a dictyostele. Each dictyostele is made up of meristeles. Companion cells are absent in the phloem and the xylem is devoid of vessels.
2. The stele is horseshoe-shaped in the upper portion of the rachis, while in its lower portion, it is made up of several meristeles.
3. Spores are present in the sporangium. Several sporangia are grouped in a sorus. Several sori remain attached on the lower surface ofthe leaves, and such leaves are called sporophylls. Sori kidney-shaped bodies. Each sorus remains covered by a layer of indusium.
4. Each sporangium is a stalked body. The edge contains 16-30, small brown cells called annulus. They possess thickenings on the inner and radial walls. The outer walls remain thin.
5. A strip of thin-walled cells on each sporangium represents the stomium. The diploid spore mother cells, present inside the sporangium, divide by meiosis, and each forms four haploid spores.
6. The spore germinates to produce a heart-shaped prothallus or gametophyte. Both the sex organs (antheridia and archegonia) and the rhizoids are present on the ventral surface of the prothallus. Archegonia are present in apical cushion and antheridia are present in rhizoidal region.
7. Antheridia are present on the lower part of the ventral surface of the prothallus, along with rhizoids. Antherozoids are uninucleate and multiflagellate.
8. Archegonia are present near the apical notch.
9. Fertilization takes place in the presence of water. Malic acid is the chemotactic substance present in the archegonium. The zygote develops into a sporophyte without reduction division. The young sporophyte remains attached to the gametophyte for some time.
10. Plants show heteromorphic alternation of generations.

Economic Importance

1. Food. Sporocarps of Marsilea are edible. The starchy pith of Angiopteris erecta and Alsophila australis is eaten by the natives of Australia.
2. Medicines. Rhizomes and petioles of Dryopteris have vermifuge properties. Adiantum roots can cure throat infections.
3. Its leaves are dried and used as a laxative. Lycopodium is used in the treatment of rheumatism and disorders of the lungs and kidneys. Equisetum arvense is a diuretic while its ash relieves acidity and dyspepsia.
4. Scrubbing. Equisetum stems have rough and abrasive surfaces. They are used in scrubbing and polishing.
5. Ornamental value. Some ferns and club mosses are grown indoors as well as in gardens for their graceful foliage.

• A few characteristics that are responsible for the successful survival of vascular plants are: deep soil penetrating root system.
• Water-saving methods developed by plants as cuticles on leaves.
• support to woody plants is provided by collenchyma, sclerenchyma, and by the lignification of wood.
• they bear a vertical main axis and a conspicuous radial symmetry around the axis. Such construction permits efficient nutrient absorption from all sides around the plant. The pteridophytes were the first plants to develop vascular tissue.
• Pteridophytes are vascular plants without flowers and seeds.
• In pteridophytes sporophyte is independent and in bryophytes the sporophyte is dependent.
• The pteridophytes are the most primitive living (For example Selaginella, Lycopodium, Equisetum) and fossil (For example Rhynia) Vascular plants.
• The absence of root hair and root cap is a stem-like character of Selaginella rhizophore.
• They are regarded as organogenesis. Resembles with stem, exogenous origin, adventitious roots, and bear leaves when injured.
• Calixylon is a fossil pteridophyte from the upper Devonian period with a trunk of 5ft. These heterosporous pteridophytes must have given rise to gymnosperms.
• Simple sori (primitive) in which all sporangia develop simultaneously.
• Gradate sori (more advanced): where sporangia develop in basipetal succession or mixed sori (most advanced): where sporangia develop in an irregular sequence.
• Dryopteris and moss form monoecious gametophytes as all spores are uniform.
• Suigenesis means neither a root nor a shoot complete but something new.
• Circinate ptyxis is shown by young leaves that are under the influence of hyponasty and they take two years to open up under the influence of epinasty.

Pteridophyta NEET Question Bank

NEET Biology Pteridophyta Quanta To Memory

• Haeckel coined the term pteridophyta (vascular cryptogam).
• Zimmaman (1930) proposed the “Telome theory” for the evolution of vascular plants. He proposed that all vascular plants have evolved from simple dichotomously branched pteridophytes such as Rhynia.
• Tree fern with upright aerial stem Example Cyathaea, Alsophila.
• Cyathaea is the tallest fem
• Rhynia is a fossil plant placed under Psilophytales.
• Salvinia , Azolla and Marsilea are water ferns.
• Spores are usually all alike ( i.e. Homosporous) Example Lycopodium, Pteris, Adiantum, Pteridium, etc. or they are of two different sizes (i.e., Heterosporous) Example Selaginella, isolates, Marsilea, Azolla, Salvinia etc.
• Dryopteris is homosporous and Selaginella is heterosporous
• Sporangia are usually borne on or in the axil of leaves
  called sporophylls. Examples are Lycopodium, Selaginella, and Pteris.
  Nephrolepis, Adiantum, etc. In some aquatic plants
  sporangia are produced within specialized structures called
  sporocarps, for Example, Marsilea, Salvinia, Azolla, Regnellidium,
  Pilularia etc.
• In pteridophytes or Ferns, the archegonia secrete malic acid which attracts the antherozoids.
• In pteridophytes ovules are absent. Selaginella and fem both are pteridophytes, so in both ovules are absent.
• Azolla, a water fem is used as a biofertilizer.
• Ferns are cultivated as ornamental plants.
• The embryo is diploid and spores are haploid.
• In the fem, the neck is small and is having a single neck canal cell with two nuclei.
• In a fern Example, Pteris or Dryopteris sex organs are produced on the lower side of the prothallus and antheridia are towards the base among the rhizoids.
• In some ferns, trophopod (a food storage organ formed by large and modified leaf base) has been found, for Example Asplenium, and Dryopterisfragrans.
• In ferns, spores are produced in sporangia after meiosis in diploid spore mother cells.
• Precocious Germination. In situ, spores germinate while in sporangium Spike. The collection of sessile sporophyll is called spike.
• Tapetum is the innermost layer of sporangial jacket. It provides nutrition and degenerates at maturity.
• Heterosporous pteridophytes like Selaginella and Marsilea always produce dioecious gametophytes because microspores will form male gametophytes and megaspores will form female gametophytes.
• The bursting point of the fem sporangium is the stomium. It is made up o£ thin walled cells. Due to tension in the annulus, stomium breaks down.
• In Selaginella, the stele is suspended by unicelled trabeculae.
• The suigenesis hypothesis of rhizophore was given by Goebel.
• Ramenta. In ferns, the multicelled, chaffy, and dry scales covering young rhizomes and leaves which prevent desiccation are called ramenta.
• In ferns, endodermis has characteristic Casparian strip.
• Stomium: The place from where the capsule opens is called the stomium.
• Golden fem— Onychium
• Walking fem = maiden hair fem — Adiantum
• Male shield fem— Dryopteris
• In Marsilea [fern] microspore forms 9 celled male gamete
• There is no annulus in Marsilea.

Pteridophyta NEET Exam Preparation

• In ferns, the xylem is mesarch in stem, petiole, and leaves while in roots it is diarchy.
• A corm-like rhizomorph occurs in isolates.
• Apospory. Development of gametophyte directly from the vegetative cells of sporophyte without formation of spores. It was first demonstrated by Druery (1884).
• Apogamy. Development of sporophyte from gametophytic tissue without involving fusion of gametes. It was first observed by Farlow in Pteris and the term apogamy was introduced by de Bary (1978)
• Eusporangium. Sporangia spore-producing structures develop from a group of initial cells Example in Psilatum Lycopodium, Equisetum.
• Leptosporangium. Sporangia originate from a single superficial cell Example in Marsilea, Pteris In some forms eg Polypodium aureum and Drynaria regidula the leaves develop prothalli under dim light but sporophytic buds under strong light.
• Rhynia was discovered from Rhyncihert Valley in
  Scotland by Mackie (1913).
• Each leaf of Selaginella bears on its upper surface near its base a small membranous, tongue-like outgrowth ligule.
• Large greatly vacuolated cells for water absorption are called glossopodium.

NEET Biology Pteridophyta Multiple Choice Questions

Question 1. Which of the following plant’s arcs is known as vascular cryptogams?

1. Angiosperms
2. Bryophytes
3. Ptcridophytcs
4. Gymnosperms.

Answer: 3. Ptcridophytcs

Question 2. The gametophytic generation in pteridophytes is commonly called:

1. Thallus
2. Plant body
3. Pro thallus
4. Protoncma.

Answer: 3. Pro thallus

Question 3. The male sex organs produced by the gametophyte are:

1. Sporangium
2. Archegonia
3. Sorus
4. Anthcridia.

Answer: 4. Anthcridia.

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 4. Ferns arc mostly :

1. Isogamous
2. Heterosporous
3. Homosporous
4. Asexual.

Answer: 3. Homosporous

NEET MCQs on Pteridophytes Question 5. Stele in fern’s rhizome is of mostly :

1. Siphonostelc
2. Solenostelc
3. Dictyostele
4. All of the above.

Answer: 3. Dictyostele

Question 6. Stele is defined as:

1. At the xylem elements of the vascular bundle
2. The cortex portion of the stem
3. Phloem of the vascular elements
4. Vascular tissue surrounded by pericycle and endodermis.

Answer: 4. Vascular tissue surrounded by pericycle and endodermis.

Question 7. The sac-like structure in which spores are enclosed in

1. Strobilus
2. Sorus
3. Sporangium
4. Sporangiophere

Answer: 3. Sporangium

Question 8. Some of the pteridophytes and gymnosperms the sporophyll aggregate at the apices of the main stem or its branches to form definite compact structures. The compact structures are called:

1. Sporangiophore
2. Sorus
3. Sporangium
4. Strobilus or cone.

Answer: 4. Strobilus or cone.

Question 9. The condition where a pteridophyte produces two kinds of spores and sporangia is termed as :

1. Homospory
2. Homothallism
3. Heterospory
4. Apospory.

Answer: 3. Heterospory

Question 10. Pteridophytes are characterized by :

1. Presence of a vascular system
2. Absence of flowers
3. Absence of fruits
4. All the above.

Answer: 4. All the above.

NEET MCQs on Pteridophytes Question 11. The main plant body of pteridophyte is :

1. Gametophyte
2. Sporophyte
3. Sporangium
4. Prothallus.

Answer: 2. Sporophyte

Question 12. Fem differs from selaginella by one of the following:

1. Absence of heterosporous form
2. In rhizoids
3. In the arrangement of leaves
4. All the above.

Answer: 1. Absence of heterosporous form

Question 13. The prothallus represents :

1. Gametophyte of fem
2. Sporophyte of angiosperm
3. Sporophyte of gymnosperm
4. Sporophyte of fem.

Answer: 1. Gametophyte of fem

Question 14. Pteridophytes differ from bryophytes in :

1. Having motile sperms
2. Having vascular tissues
3. Archegonia
4. Alternation of generations.

Answer: 2. Having vascular tissues

Question 15. Adaxial outgrowth from the base of leaves in selaginella is called:

1. Stipule
2. Ligule
3. Trabeculae
4. Velum.

Answer: 2. Ligule

Question 16. The function of ligule is :

1. Hygroscopic
2. Permutation
3. Reproduction
4. All the above.

Answer: 1. Hygroscopic

Pteridophytes MCQs NEET Questions Question 17. Rhizophore of selaginella is :

1. Phototropic
2. Phototactic
3. Gcotropic
4. Hygroscopic.

Answer: 3. Gcotropic

Question 18. Selaginella is characterized by the presence of:

1. Homospory
2. Ligule
3. Flower
4. None of the above.

Answer: 2. Ligule

Question 19. Rhizophore positive geotropic structure of selaginella is :

1. Root
2. Stem
3. A new organ called subgenres
4. None of the above.

Answer: 3. A new organ called subgenres

Question 20. The dominant generation in selaginella is :

1. Haploid
2. Gametophyte
3. Triploid
4. Diploid.

Answer: 4. Diploid.

Pteridophytes MCQs NEET Questions Question 21. When a spore germinates within a sporangium, it is called :

1. Precocious
2. Epigeal
3. Heteroecious
4. Hypogeal.

Answer: 1. Precocious

Question 22. One character common for selaginella and fem is :

1. Heterospory
2. Protostele
3. Development of sporangium
4. Absence of ovule.

Answer: 4. Absence of ovule.

Question 23. Microsporangia and megasporangia are found in same strobilus in :

1. Fem
2. Selaginella
3. Pinus
4. Moss.

Answer: 2. Selaginella

Question 24. Heterospory is the production of :

1. Sexual and asexual spores
2. Mega and microspores
3. Haploid and diploid spores
4. Haploid and tetraploid spores.

Answer: 2. Mega and microspores

Question 25. Prothallus of dryopteris is :

1. Haploid
2. Diploid
3. Triploid
4. Tetraploid.

Answer: 1. Haploid

MCQs on Pteridophyta Question 26. Rhizophore in selaginella is :

1. Exogenous in origin
2. Endogenous in origin
3. Internal in origin
4. None of the above.

Answer: 1. Exogenous in origin

Question 27. The number of megaspores in Selaginella rupestris is:

1. One
2. Two
3. Three
4. Four.

Answer: 1. One

Question 28. Selaginella differs from moss in having:

1. Well-developed vascular system
2. Motile sperms
3. An independent gametophyte
4. Both a and c.

Answer: 1. Well-developed vascular system

Question 29. Development of embryo in selaginella is :

1. Meroblastic
2. Holoblastic
3. Aposporous
4. None of the above.

Answer: 1. Meroblastic

MCQs on Pteridophyta Question 30. In selaginella, male gametes are :

1. Monoflagellated
2. Biflagellated
3. Multiflagellated
4. Aflagellate.

Answer: 2. Biflagellated

Question 31. Gametangia of fern are produced on :

1. Leaves
2. Sorus
3. Prothallius
4. Ramcntn.

Answer: 3. Prothallius

Question 32. Mciistclos a found in:

1. Stem of cycas
2. Needle of pinus
3. Leaf of patterns ferm
4. Rhizome of fern

Answer: 4. Rhizome of fern

Question 33. According to available loss iris which of the following went to install hand vascular 

1. Psilopliv tales
2. Lycopods
3. Horse-tail
4. Cycas

Answer: 1. Psilopliv tales

MCQs on Pteridophyta Question 34. Sporangia and spore-bearing leaf in fem is called a

1. Ramentum
2. Sorus
3. Lndusium
4. Sporophyll.

Answer: 4. Sporophyll.

Question 35. Which of the following is not heterosporous?

1. Dryopteris
2. Selaginella
3. Marsilea
4. Pinus.

Answer: 1. Dryopteris

Question 36. The annulus of the sporangium of the ferns assists in the spore dispersal by:

1. Losing water from its cells
2. Taking up water from the air
3. Collapsing in the face of strong wind
4. Losing the air of its cells.

Answer: 1. Losing water from its cells

Question 37. In many ferns, spore dissemination is affected by

1. Annulus
2. Lndusium
3. Tapetum
4. Soms.

Answer: 1. Annulus

Question 38. Actinostele is related to :

1. Dictyostele
2. Protostele
3. Siphonostele
4. Solenostele.

Answer: 2. Protostele

Question 39. The tallest pteridophyte is :

1. Equisetum
2. Cyathaea
3. Dryopteris
4. Lycopodium.

Answer: 2. Cyathaea

Pteridophytes NEET Biology  Question 40. Gametophyte of fem is known as :

1. Protonema
2. Germling
3. Prothallus
4. Capsule.

Answer: 3. Prothallus

Question 41. Two distinct generations in a single life history are common in :

1. Bacillus
2. Mango
3. Pteris
4. Spirogyra.

Answer: 3. Pteris

Question 42. A stele without a central pith is called :

1. Solenostele
2. Protostele
3. Dictyostele
4. Siphonostele.

Answer: 4. Siphonostele.

Question 43. Multiflagellate antherozoids are found in :

1. Spirogyra
2. Ulothrix
3. Funaria
4. Dryopteris.

Answer: 4. Dryopteris.

Pteridophytes NEET Biology  Question 44. Vessels are absent in :

1. Spirogyra and ulothrix
2. Rhizopus and funeral
3. Dryopteris and cycas
4. All the above.

Answer: 4. All the above.

Question 45. Eed habit originated in :

1. Pteridophytes
2. Gymnosperms
3. Angiosperms
4. None of the above.

Answer: 1. Pteridophytes

Question 46. The leaves in ferns show :

1. Hypostomatic condition
2. Presence of sori on the ventral surface
3. Circinate ptyxis
4. All the above.

Answer: 4. All the above.

Question 47. Pteris and cycas resemble each other in the presence of:

1. Cambium
2. Vessels
3. Ciliated sperms
4. Seeds.

Answer: 3. Ciliated sperms

Question 48. Which of the following is a fossil pteridophyte?

1. Lycopodium
2. Selaginella
3. Psilotum
4. Rhynia.

Answer: 2. Selaginella

Pteridophytes NEET Biology  Question 49. In Dryopteris, antherozoids are :

1. Coiled and multi-flagellate
2. Coilet,l and hi flagellate
3. Sickle-shaped and multi-flagellate
4. Sickle-shaped and hi flagellate

Answer: 1. Coiled and multi flagellate

Question 50. In pteridophytes. The reduction division occurs, when:

1. Spores are formed
2. Gametes are formed
3. Prothallus is formed
4. Sex organs are formed.

Answer: 1. Spores are formed

Question 51. Ramenta are found in

1. Fern
2. Mosses
3. Maize
4. Dicots

Answer: 1. Fern

Question 52. Lycopodium is :

1. Isogamous
2. Homosporous
3. Heterosporous
4. Heterogamous

Answer: 2. Homosporous

Question 53. Which of the following pteridophytes shows die chloroplast having pyrenoids :

1. Equisetum
2. Selaginella
3. Pteridium
4. Marsilea.

Answer: 2. Selaginella

Question 54. Heterospory and seed habit are often discussed about a structure called :

1. Spathe
2. Bract
3. Petiole
4. Ligule.

Answer: 4. Ligule.

Question 55. The opening mechanism of sporangium in dryopteris is effectively operated by :

1. Annulus only
2. Stomium only
3. Annulus and stomium both
4. Apical opening.

Answer: 3. Annulus and stomium both

Question 56. Which of the following has amphiphloic siphonostele?

1. Rhizome of marsilea
2. Stem of lycopodium
3. Rhizome of pteris
4. Stem of equisetum.

Answer: 1. Rhizome of Marsilea

Pteridophytes NEET Biology  Question 57. Which one of the following is common to pteridophytes and bryophytes?

1. Dependent gametophyte on sporophyte
2. Sporophyte dependent on gametophyte
3. Multicelled sex organs with sterile jacket wall
4. Absence of sporophyte.

Answer: 3. Multicelled sex organs with sterile jacket wall

Question 58. While entering the neck of an archegonium in fem, sperms show:

1. Phototaxy
2. Chemotaxis
3. Themiotaxy
4. Cyclosis.

Answer: 2. Chemotaxy

Question 59. 200-Million years ago, the dominant flora of die earth was of:

1. Archaebacteria
2. Mosses and ferns
3. Gymnosperms
4. Angiosperms.

Answer: 3. Gymnosperms

Question 60. “Maidenhair fem” is:

1. Dryopteris
2. Azolla
3. Adiantum
4. Pteris.

Answer: 3. Adiantum

Question 61. chlorophyll or chloroplast is present in spores of

1. Lycopodium
2. Selaginella
3. Dryopteris
4. Marsilea.

Answer: 1. Lycopodium

Question 62. The process by which an embryo develops without involving gametic fusion is called :

1. Apospory
2. Syngamy
3. Apogamy
4. Isogamy.

Answer: 3. Apogamy

NEET Biology Plant Kingdom Bryophyta Multiple Choice Questions

Question 1. The proponent of moss resembles the green alga. It differs from green alga in having:

1. Buds
2. Colourlcss rhizoids
3. Oblique sepia and discoid chloroplast
4. All of the above.

Answer: 4. All of the above.

Question 2. Sex organs in funerals develop :

1. At The axils of leaves
2. At the lip of the gametophore
3. In the protonema
4. Inside the capsule.

Answer: 2. At the lip of gametophore

Question 3. The green upright sterile hair-like structure among antheridia of funeral are known as :

1. Apophysis
2. Perigonial teeth
3. Trabeculae
4. Paraphyses.

Answer: 4. Paraphyses.

Question 4. A bryophyte of considerable economic importance is :

1. Marchantia
2. Riccia
3. Funaria
4. Sphagnum.

Answer: 4. Sphagnum.

Bryophytes Recommended MCQs NEET Question 5. In funaria meiosis occurs :

1. At the time of spore formation
2. When the nucleus of the zygote divides
3. At the time of the formation of Sperms
4. At the time of egg formation.

Answer: 1. At the time of spore formation

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 6. Anchorage organs of the funeral are :

1. Unicellular rhizoids
2. Adventitious roots
3. Multicellular rhizoids
4. True roots.

Answer: 3. Multicellular rhizoids

Question 7. Which one of the following is absent in the sporophyte of the funeral?

1. Foot
2. Seta
3. Elaters
4. Columella.

Answer: 3. Elaters

Question 8. Apophysis is :

1. Part of peristome of funaria
2. Sterile filaments among antheridia of moss
3. Terminal part of sporophylls of Pteris
4. The lower portion of the moss capsule.

Answer: 4. Lower portion of moss capsule.

Question 9. In the funeral, intermingled with the archegonia are present upright hairs called :

1. Scales
2. Rhizoids
3. Paraphysis
4. Periphyses.

Answer: 3. Paraphysis

Question 10. Which of the following is a diploid?

1. Capsule of moss
2. Gametophyte, archegonia, and egg of moss
3. Gamclophyte, antheridia, and sperm of moss
4. Gametophyte and spore of moss.

Answer: 1. Capsule of moss

Bryophytes Recommended MCQs NEET Question 11. Which of the following is not associated with moss capsules?

1. Trabeculae
2. Peristome
3. Columella
4. Stomium.

Answer: 4. Stomium.

Question 12. The function of the peristome in moss is

1. Spore dispersal
2. Nutritive
3. Protective
4. Absorption of water and mineral,

Answer: 1. Spore dispersal

Question 13. In which of the following sporophytes remains attached to gametophytes?

1. Fungi
2. Gymnosperms
3. Algae
4. Bryophytes

Answer: 4. Bryophytcs

Question 14. The function of craters is :

1. Absorption of food
2. Conduction of sap
3. Spore dispersal
4. To provide support.

Answer: 3. Spore dispersal

Question 15. A bryophyte differs from pteridophyte in:

1. Archegonia
2. Lack of vascular tissue
3. Antheridia
4. Sperms

Answer: 2. Lack of vascular tissue

Bryophytes Recommended MCQs NEET Question 16. Development of sporophyte from gametophyte cells without fertilization is called :

1. Apospory
2. Apogamy
3. Parthenogenesis
4. Syngamy.

Answer: 2. Apogamy

Question 17. In bryophytes, diploid chromosome number occurs in :

1. Spore mother cell
2. Gametes
3. Sperms
4. Meiospores.

Answer: 1. Spore mother cell

MCQs on Bryophyta for NEET Question 18. Gemmae are vegetative reproductive structures found in:

1. Angiosperms
2. Bryophytes
3. Algae
4. Gymnosperms.

Answer: 2. Bryophytes

Question 19. Which bryophyte has simplest sporophyte :

1. Riccia
2. Marchantia
3. Anthoceros
4. Funaria.

Answer: 1. Riccia

Question 20. Female sex organ in riccia and funaria is called:

1. Paraphysis
2. Oospore
3. Archegonium
4. Artheridium.

Answer: 3. Archegonium

Question 21. When gametophyte develops from sporophyte without the production of spores it is called:

1. Apogamy
2. Parthenogenesis
3. Apospory
4. Sporogenesis.

Answer: 3. Apospory