NEET Biology

NEET Biology Respiratory System In Animals Multiple Choice Questions

Question 1. An increase in the CO2 concentration shifts the shape of the oxyhaemoglobin dissociation curve to the light. This phenomenon is known as

1. Bohrs effect
2. Hamburfurs effect
3. Newtons effect
4. None of the above

Answer: 1. Bohrs effect

Question 2. What are the respective percentages of  O₂ in air we inhale and exhale?

1. 16.3, 3.00
2. 20.94, 16.30
3. 20.94,00
4. 20.3, 3.00.

Answer: 2. 20.94, 16.30

Question 3. According to modern  view, the blood that enters the Kings of Frogs is:

1. Oxygenated
2. Mixed
3. Deoxygenated
4. Low in glucose level.

Answer: 2. Mixed

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 4. This stage when a lung collapses, especially the alveoli is:

1. Atelectasis
2. Poliomyelitis
3. Asthma
4. Cpistasis.

Answer: 1. atelectasis

MCQs on Respiratory System Question 5. Oxyhaemoglobin is an unstable compound because :

1. One haemoglobin molecule binds 4 molecules of oxygen
2. Haemoglobin is a complex pigmented protein
3. Haemoglobin is contained within RBCs
4. Oxygen and haemoglobin are not chemically bound but only physically combined.

Answer: 4. Oxygen and haemoglobin are not chemically bound but only physically combined.

Question 6. Carboxyhaemoglobin is formed due to the combination of haemoglobin with :

1. CO
2. HCN
3. CO,
4. CH₄

Answer: 1. CO

Question 7. Mouth-to-mouth breathing proves useful in the resuscitation of a drowned person because expired air from the resuscitator:

1. does not contain any oxygen
2. contain a considerable amount of oxygen
3. contain considerable oxygen and CO₂, to stimulate breathing
4. contain largely N0 and traces of CO₂

Answer: 3. contain considerable oxygen and CO₂, to stimulate breathing

Question 8. During one circuit of blood from the lungs to the tissue and back through the circulatory system, the percentage of haemoglobin giving up oxygen is:

1. 50%
2. 25%
3. 75%
4. 100%.

Answer: 2. 25%

Question 9. Among all the systems of an organism the one which is not concerned with respiration is:

1. Nervous
2. Digestive
3. Excretory
4. Endocrine.

Answer: 3. Excretory

MCQs on Respiratory System Question 10. Which of these does not apply to the air that reaches into the lungs of rabbits, when compared with the air of the atmosphere?

1. Its temperature is equal to that of the animal’s body
2. It contains no bacteria, virus or spores
3. It is quite dry
4. It is moist.

Answer: 3. It is quite dry

Question 11. Which Of the following statements is correct?

1. Anaerobic respiration yields considerably more energy
2. Aerobic respiration yields more energy than anaerobic respiration
3. Both release equal amounts of energy
4. Anaembie respiration yields slightly more energy than Aembie respiration.

Answer: 2. Aerobic respiration yields more energy than anaerobic respiration

Question 12. Vocal cords are :

1. two folds of mucous membrane
2. four folds of mucous membrane
3. two folds of cartilage
4. four layers of cartilage.

Answer: 1. two folds of mucous membrane

Question 13. The carbon dioxide in the atmosphere is almost entirely produced by :

1. Forest Ore
2. Respiration by plants and animals
3. Microbial activity
4. Furnaces of industries.

Answer: 2. respiration by plants and animals

Question 14. What structures are responsible for raising of throat in frogs?

1. Hyoglossal muscles
2. Stemohyal muscles
3. Petrohyal muscles
4. None of the above.

Answer: 3. Petrohyal muscles

NEET Respiratory System Question 15. During hibernation frog respires by :

1. Lungs
2. Lining of buccal epithelium
3. Skin
4. None of the above.

Answer: 3. skin

Question 16. Respiratory organs should be :

1. thin-walled
2. thick-walled
3. non-vascular
4. covered by scales.

Answer: 1. thin-walled

Question 17. In addition to other gases and water vapours, expired air contains:

1. Cl₂
2. SO₂
3. CO₂
4. O₂.

Answer: 3.CO₂

Question 18. During external respiration, oxygen is first accepted by :

1. lungs
2. alveolar capillaries
3. W.B.C.s
4. R.B.C.s.

Answer: 4. R.B.C.s

NEET Respiratory System Question 19. In humans, the bulk of C09 released in tissue respiration is transported by blood as:

1. carbonic acid in plasma
2. sodium bicarbonate in erythrocytes
3. carbamino haemoglobin in erythrocytes
4. ammonium bicarbonates in erythrocytes.

Answer: 2. sodium bicarbonate in erythrocytes

Question 20. The rate of respiration increases due to :

1. exercise
2. rest
3. sleep
4. None of these.

Answer: 1. exercise

Question 21. Gas used up during respiration is:

1. CO₂
2. O₂
3. N₂
4. Ozone.

Answer: 2. O₂

Question 22. The index of pulmonary function is the :

1. air left in the lung after a maximum forced exhalation
2. the greatest amount of air that can expire after a maximal inspiratory effort inspiration
3. amount of air that moves out with normal inspiration.
4. amount of air present in the lung at a time.

Answer: 2. the greatest amount of air that can expire after a maximal inspiratory effort inspiration

Question 23. Epiglottis guards the opening of the :

1. pharynx
2. larynx
3. gullet
4. trachea.

Answer: 2. larynx

Question 24. The exchange of gases between the alveolar air and alveolar capillaries takes place by :

1. Exosmosis
2. Diffusion
3. Active transport
4. Endosmosis.

Answer: 2. Diffusion

NEET Respiratory System Question 25. Haemoglobin has an affinity for :

1. CO₂
2. _O2
3. N₂
4. None of these.

Answer: 2. O₂

Question 26. Pneumonia is a disease of:

1. Alimentary canal
2. Heart
3. Brain
4. Respiratory tract.

Answer: 4. Respiratory tract

Question 27. Trachea is supported by :

1. Bone
2. Cartilage
3. Cardiac muscles
4. None of these.

Answer: 2. Cartilage

Question 28. With the increase in temperature, the respiratory rate will:

1. increase
2. decrease rapidly
3. remain unaffected
4. decrease slowly.

Answer: 1. increase

Question 29. The end product of anaerobic respiration is :

1. C0₉ and H₂0
2. Fumaric acid
3. Arctic acid
4. Acetic acid.

Answer: 3. Lactic acid

NEET Biology Breathing and Exchange of gases  Question 30. The gas exchange surface for most large aquatic animals are:

1. trachea
2. gills
3. book lungs
4. malpighian tubules.

Answer: 2. gills

Question 31. An advantage of gas exchange in aquatic habitats as compared with terrestrial habitats, is that it is easier to keep gas exchange surfaces:

1. wet
2. ventilated
3. free of injury
4. saturated with oxygen.

Answer: 1. wet

Question 32. A disadvantage of gas exchange in aquatic habitats, as compared with terrestrial habitats, is that:

1. gas exchange surface tends to collapse
2. oxygen concentration in water is much lower than in air
3. CO2 concentration is much lower in water than in air
4. None of the above.

Answer: 2. oxygen concentration in water is much lower than in air

Question 33. An animal has some way of moving air or water across its gas exchange surface, a process known as:

1. counter-current exchange
2. ventilation
3. facilitated diffusion
4. active transport.

Answer: 2. ventilation

Question 34. A frog cannot live long unless it resorts to :

1. cutaneous respiration
2. pulmonary respiration
3. buccal respiration
4. None of the above.

Answer: 1. cutaneous respiration

NEET Biology Breathing and Exchange of gases  Question 35. Frogs while completely submerged in water respires through :

1. Skin
2. Skin and lining of the buccal cavity
3. Lung
4. skin, the lining of the buccal cavity and the lung.

Answer: 2. skin and lining of the buccal cavity

Question 36. The expiration in human lungs is due to :

1. Contraction of lung
2. Lowering of hyoid cartilage
3. Ribs and their intercostal muscles
4. Contraction of the lung and raising of hyoid cartilage.

Answer: 3. ribs and their intercostal muscles

Question 37. The percentage composition of carbon dioxide in the expired air is about:

1. Two
2. Four
3. One
4. Seven.

Answer: 2. Four

Question 38. The percentage composition of oxygen in the expired air is about:

1. twenty
2. ten
3. sixteen
4. eight.

Answer: 3. sixteen

Question 39. The volume of air that can be expired after a maximal inspiratory effort is :

1. residual volume
2. expiratory reserve volume
3. inspiratory reserve volume
4. lung volume.

Answer: 2. expiratory reserve volume

NEET Biology Breathing and Exchange of gases  Question 40. The meeting point of all metabolic pathways is :

1. lactic acid
2. citric acid
3. ornithine cycle
4. acetyl Co-A.

Answer: 4. acetyl co-A

Question 41. The major fraction of CO2 produced and released during cell respiration is transported to the respiratory site in frogs:

1. as carbonic acid
2. as free CO2
3. in combination with Hb
4. in the form of bicarbonate ions.

Answer: 4. in the form of bicarbonate ions

Question 42. Both hyperventilation and holding of one’s breath can cause loss of consciousness. Under normal circumstances, why does this happen?

1. Alteration of carbon dioxide levels in the blood
2. Alteration of oxygen levels in the blood
3. Loss of haemoglobin from red blood cells
4. Excess dissociation of oxygen from haemoglobin.

Answer: 1. Alteration of carbon dioxide levels in the blood

Question 43. The main difference between the insect tracheal system and most other types of respiratory system is :

1. the tracheal system does not rely on the blood to transport oxygen to the tissues
2. insects do not ventilate their tracheal system
3. insects do not dispose of CO₂via a tracheal system
4. insects exchange both CO₂ and O₂ via their tracheal system.

Answer: 1. The tracheal system does not rely on the blood to transport oxygen to the tissues

Respiratory system NEET Biology Question 44. The membrane-bound enzyme involved in Krebs’ cycle is:

1. malate dehydrogenase
2. fumarase
3. cis-aconitase
4. succinic dehydrogenase.

Answer: 4. succinic dehydrogenase

Question 45. The blood leaving dead lungs leaves all its haemoglobin present in the oxygenated form and gives up oxygen to the tissues Ixvause :

1. the tissue can absorb O2 from oxyhaemoglobin
2. the reduction reaction of oxyhaemoglobin
3. O2 conc. in the tissue is lower, CO2 conc. higher than in the lungs
4. O2 conc. in the tissue is higher, CO2 conc. lower than in the lungs

Answer: 3. O2 conc. in the tissue is lower, CO2 conc. higher than in the lungs

Question 46. Breathing rate in human beings is :

1. 16 times per minute
2. 25 times per minute
3. 72 times per minute
4. 5 times per minute.

Answer: 1. 16 times per minute

Question 47. When the exchange of gases occurs between blood and tissue fluid, it is called :

1. external respiration
2. internal or tissue respiration
3. cellular respiration
4. All the above.

Answer: 2. internal or tissue respiration

Question 48. Blood has no role in the transport of oxygen in :

1. lungfish
2. molluscs
3. insects
4. leech.

Answer: 3. insects

Respiratory system NEET Biology Question 49. The surface area of human beings is made much larger by alveoli and is approximately the size of a :

1. dinner plate
2. drawing room
3. tennis court
4. four-person tent.

Answer: 3. tennis court

Question 50. Higher energy compounds are :

1. which links the exergonic to the endergonic process
2. produced in respiration
3. produced when ATP loses two of its phosphate groups
4. the oxidation of which releases large amounts of energy during respiration.

Answer: 4. the oxidation of which releases large amounts of energy during respiration

Question 51. Chloride shift is essential for the transport of:

1. CO₂ and O₂
2. N₂
3. CO₂
4. _O2

Answer: 3. CO₂

Question 52. In the liver, the amino acids are oxidised resulting in the removal of amino groups from amino acids and the formation of ammonia and a keto acid. It is termed as :

1. transamination
2. ketosis
3. deamination
4. ketogenesis.

Answer: 3. ketogenesis

Respiratory system NEET Biology Question 53. The excess amino acids and fats are converted into carbohydrates in the liver. The process is known as :

1. glycolysis
2. glycogenosis
3. gluconeogenesis
4. glugogenesis.

Answer: 3. gluconeogenesis

Question 54. All land vertebrates essentially have :

1. pharynx
2. larynx
3. gills
4. lungs.

Answer: 4. lungs

Question 55. The lung is lined by :

1. dry epithelium
2. moist epithelium
3. squamous epithelium
4. endothelium.

Answer: 2. moist epithelium

Question 56. Under glycolysis, the pyruvic acid is reduced to lactic acid anaerobically in :

1. liver
2. muscles
3. brain
4. skin.

Answer: 2. muscles

Question 57. On oxidation one of the billowing yields more water:

1. sugar
2. starch
3. proteins
4. Fats.

Answer: 1. sugar

Question 58. We get a major supply of energy from glucose via :

1. fat metabolism
2. Krebs’ cycle
3. lactic acid
4. pyruvic acid.

Answer: 2. Krebs’ cycle

Respiratory system NEET Biology Question 59. Real respiration involving energy release is:

1. expiration
2. breathing
3. cell respiration
4. inspiration.

Answer: 3. cell respiration

Question 60. The lungs of a frog are :

1. thin-walled, inelastic and solid bags
2. thick-walled, elastic and hollow bags
3. thin-walled, elastic, hollow bags
4. thick-walled, hollow and spongy.

Answer: 3.  thin-walled, elastic, hollow bag

Question 61. Approximately, how many alveoli are present in each human lung?

1. 100 million
2. 150 million
3. 200 million
4. 300 million.

Answer: 2. 150 million

Question 62. Each lung is enclosed in a two-layered pleural membrane. The outer layer of the pleural membrane remains attached to:

1. trachea
2. wall of the thoracic cavity
3. diaphragm
4. ribs.

Answer: 2. wall of the thoracic cavity

Question 63. Alveolar ducts which lead to alveoli are formed by the subdivision of:

1. bronchi
2. tracheoles
3. bronchioles
4. terminal bronchioles.

Answer: 4. terminal bronchioles

Respiratory system NEET Biology Question 64. Which of the following is a step of the mechanism of respiration?

1. Pulmonary ventilation
2. Exchange of gases
3. Transport of gases
4. All of the above.

Answer: 4. All of the above

Question 65. The downward and upward movement of the diaphragm :

1. lengthens and shortens the chest cavity
2. only increases the chest cavity
3. decreases the chest cavity
4. No effect on the size of the chest cavity.

Answer: 1. lengthens and shortens the chest cavity

Question 66. During pulmonary ventilation, the diameter of the chest cavity is decreased by :

1. elevation of ribs
2. depression of ribs
3. diaphragm becoming flat
4. abdominal viscera moves down.

Answer: 2. depression of ribs

Question 67. Tidal volume and IRV are collectively termed :

1. functional residual capacity
2. pulmonary inspiratory capacity
3. vital capacity
4. ERV.

Answer: 2. pulmonary inspiratory capacity

Question 68. At a particular pressure, the diffusion of CO-, is how much faster as compared to diffusion of oxygen?

1. 10 times
2. 20 times
3. 30 times
4. Equal.

Answer: 2. 20 times

NEET Respiratory System Question 69. During strenuous exercise, the Po, in the tissue falls, as a result of which, the blood at tissue level has merely 4.4 ml of oxygen/100 ml of blood. Thus how much oxygen is transported by the haemoglobin of blood during exercise?

1. 15 ml
2. 20 ml
3. 30 ml
4. 35 ml.

Answer: 1. 15 ml

Question 70. What is the capacity of 1 gm of haemoglobin to combine with oxygen?

1. 34 ml
2. 1.34 ml
3. 2.34 ml
4. 3.12 ml.

Answer: 2. 1.34 ml

Question 71. Which one is correct?

1. Respiratory centres are not affected by CO2 conc.
2. During inspiration, the lungs act as a suction jump
3. There are  10³ alveoli in human lungs
4. The vital capacity of a healthy person is 800 cc.

Answer: 2.  During inspiration lungs act as a suction jump

Question 72. Which of the following represents the correct oxygen haemoglobin dissociation curve :

Answer: 3.

NEET Respiratory System Question 73. Which of the following is an occupational lung disease?

1. Silicosis
2. Asbestosis
3. Minamata
4. Both 1 and 2.

Answer: 4. Both 1 and 2

Question 74. If O₂ concentration in tissues were almost as high as at the respiratory surface :

1. oxyhaemoglobin would dissociate to supply O₂ to the tissues
2. haemoglobin would combine with more O₂ at the respiratory surface
3. Oxyhaemoglobin would not dissociate to supply O2 to the tissues
4. CO₂ will interfere with O₂ transport

Answer: 3. Oxyhaemoglobin would not dissociate to supply O2 to the tissues

Question 75. Match the structure listed under Column – 1 with the functional names given under Column – 2; choose the answer which gives the correct combination of the alphabets of the two columns

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

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

Question 76. Respiration is performed by the intestine in :

1. Toad Pipa
2. Fish, Misgumus
3. Tortoise
4. Toad Xenopus.

Answer: 2. Fish, Misgumus

Question 77. The structures participating in the air inhalation are :

1. diaphragm and internal intercostal
2. diaphragm and external intercostal
3. abdominal muscles and internal intercostal
4. All of the above.

Answer: 2. diaphragm and external intercostal

Question 78. In mammals, most of the CO2 is transported as NaHC03 and KHC03 in the blood. It is between :

1. 10-30%
2. 50 – 70%
3. 80 – 85%
4. 90 – 95%

Answer: 3 80 – 85%

NEET Biology Animal Reproductive System

• Embryology: It is the study of events and changes that take place from fertilization to the hatching or birth of an individual and includes the changes of the prenatal period only.
• Developmental Biology: It is the study of the ontogenic development process by which organism undergoes changes in their structure and physiology during their entire life and includes the entire changes from fertilization to death.
• Reproduction: The process of producing the young ones of its type is called reproduction.

NEET Biology Animal Reproductive System Forms Of Reproduction

Asexual and Sexual reproduction are the two main forms of reproduction in animals.

• Asexual Reproduction: It is a type of multiplication in which an offspring is formed from a specialized or unspecialized part of the parent without the formation and fusion of sex cells and the process is termed blastogenesis.

Basic features of asexual reproduction:

1. Only one parent is involved.
2. All the cell divisions are mitotic.
3. All the offspring are genetically similar to the parent.
4. The reproductive unit is a fragment or specialized part of the parent.

Read and Learn More NEET Biology Notes

The different ways of asexual reproduction are :

• Budding, fission, fragmentation, plastotomy, etc. Budding may be external ExamplePorifers and Hydra) or internal Example Spongilla).
  • Fission may be binary Example Euglena) or multiple (Plasmodium)
    Fragmentation Example Earthworm), Sporulation ExampleAmoeba) Another asexual method is either androgenesis or gynogenesis.
• Sexual Reproduction: It is a type of reproduction that takes place through the formation and fusion of gametes and form zygotes and undergoes division to form an embryo, the process is termed embryogenesis.

Reproductive System In Animals NEET Notes

Types Of Sexual Reproduction

Basic features of sexual reproduction

1. Development of male and female organs.
2. Meiosis occurs in the life cycle.
3. Production of a large number of male and female gametes.
4. Motility of male gametes.
5. Hie two types of gametes fuse and they produce a diploid structure called a zygote.
6. A zygote produces an embryo by different changes.
7. Only the mature individuals can produce the gametes.

NEET Biology Animal Reproductive System Sexual Reproduction In Humans

The reproductive system is formed of primary sex organs, viz. testes and ovaries, which produce haploid gametes by meiosis.

• Secondary sex organs, organs that perform important functions in reproduction but neither produce gametes nor secrete sex hormones, are called secondary sex organs, Example prostate and seminal vesicles, Cowper’s glands in male and fallopian tubes, and also produce sex hormones uterus and vagina in the female.
• Accessory sex organs are the distinct structures or characters that distinguish the sex of a species in appearance viz. facial hair, broad larynx, etc. in males and breasts in females.

NEET Biology Animal Reproductive System Male Reproductive System

It is formed of testes present in the scrotal sacs; epididymis to store the sperms; vasa deferentia for conduction of sperms and penis as an intromittent organ. Testis consists of numerous coiled seminiferous tubules (crypts). Each is lined by germinal epithelium formed of germ cells and Sertoli (nurse) cells. Germ cells produce spermatozoa which obtain nutrition from the sertoli cells.

• The interstitial cells (Leydig’s cells) of the testis produce the male sex hormone, testosterone. Secondary sex glands of males include a prostate, two seminal vesicles, and two Cowper’s glands. The secretion of these glands, along with the sperms, form the semen.
• The human male reproductive system includes the testes, epididymis, vasa deferentia, seminal vesicle, prostate gland, urethra, bulbourethral gland, and intromittent organ penis.
• The Testes (Spermaries) or Male Gonads
• In the embryo, the testes develop along the posterior wall of the abdomen. Shortly before birth, they descend into a fleshy sac scrotum which hangs away from the body wall between the thighs. The penis and scrotum together constitute the male external genitalia.
• If the testes do not descend, sterility occurs because normal sperm production is inhibited by internal body temperature, hence a cooler temperature is required. Temperature in the scrotum is about 2 to 3° C cooler than those in the abdomen. Failure of the testes to descend into the scrotal sac is called cryptorchidism.
• In the wall of the scrotum, there is a layer of smooth muscle, the dartos muscle, which responds to changing temperature. In the cold, this muscle contracts, and the testes are drawn closer to the abdomen for warmth, while heat causes the muscles to relax and the testes descend further for cooling.
• Internally, the testes are subdivided roughly into many compartments, each of which contains tightly coiled tubules, the seminiferous tubules, where sperms are produced by spermatogenesis from sperm mother cells.
• Along the outer wall of these tubules, are specialized cells, called spermatogonia.
• Surrounding the spermatogonia and the developing sperm are large cells called Sertoli cells. These cells provide protection, support, and nourishment to the developing sperm. Sertoli cells provide a barrier that protects sperm from an attack by the body’s immune system.
• After puberty, millions of sperm mature each day. A male continues to make sperm from puberty until death, though the number of living sperm arc reduces with age.
• Each ejaculation releases semen (a volume of fluid containing up to 300 million
  sperm). If a male releases fewer than 60 million sperm is usually considered infertile.

Reproductive System In Animals NEET Notes

NEET Biology Animal Reproductive System Transport Or Sperms

• Maturing spends are washed down in scmmilcnnis mimics by scaling Irom Sertoli cells and begin a long journey that may end in lentil/nylon.
• From die tubules, (be sperms enter the epididymis, then the vas deferens, and eventually the urethra. Along the way. three accessory glands – the seminal vesicles i.e., And the bulbourethral glands, contribute secretions.
• Together with the sperm, these secretions form semen. Tint semen is a thick whitish fluid that contains fluid from accessory glands.
• In each testis, the epididymis is a long coiled tube, where the sperm can be stored while they mature. The wall of the epididymis contains smooth muscle which can contract rhythmically to propel the sperm into the vas deferens during ejaculation

NEET Biology Animal Reproductive System Female Reproductive system

It comprises a pair of ovaries, two fallopian tubes, a uterus, and a vagina. Each ovary is encased by germinal epithelium composed of germ cells that develop into primary follicles.

• A primary follicle transforms into a Graafian follicle due to the action of FSH. Ovulation is regulated by luteinizing hormone (LH). The ovaries secrete estrogens and progesterone hormones.
• The fallopian tubes transport the ovum to the uterus, which serves as the site for fetal development throughout gestation, while the vagina functions as the delivery canal. The vulva is the external genitalia of females.
• Breasts are secondary sexual characteristics in females. Their size is contingent upon ovarian estrogens throughout puberty and lactogenic hormone following parturition.

NEET Biology Animal Reproductive System Female Gonads The Ovaries

The paired ovaries produce an egg each month. Ovaries lie on the lateral wall of the upper pelvic cavity and are held in position by supportive ligaments.

• Each ovary’ is covered with a layer of germinal epithelium. Within this covering, there are small sac-like structures, called ovarian (Graafian) follicles.
• These follicles pass through different stages of development: primary follicles, secondary follicles, and mature follicles.
• The small primary follicle consists of a single layer of cells and contains an immature ovum. The follicle cells support and protect the developing ovum and also produce the hormone estrogen, which maintains a woman’s secondary sex characteristics.
• The larger secondary follicle develops from the primary follicle and supports the maturation of the ovum.
• The next stage is the graafian follicle which has several layers of cells and a fluid-filled cavity surrounding the developing ovum.
• The immature ovum released from the Graafian follicle is called ovulation. Ovulation occurs about once a month. After ovulation, the follicle structure changes into a hormone-secreting structure, the corpus luteum, before degrading.
• The development of the follicle and the release of an immature ovum at ovulation are both initiated and controlled by follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland. The ovum will become completely mature only if it is fertilized by a sperm.
• At the time of birth, a female baby has about 500000 primary oocytes. During her life, she will make no more, most of them will degenerate before puberty. Only about 500 will develop sufficiently to be released by ovulation.

NEET Biology Animal Reproductive System Oviducts (Fallopian tubes)

The two oviducts transport the secondary oocyte to the uterus. One end of each tube attaches to the uterus, while the opposite end develops into a funnel-shaped structure known as fimbriae, which loosely encircles the ovary. Fertilization often transpires in the proximal portion of the fallopian tube.

NEET Biology Animal Reproductive System Uterus

The uterus is a hollow pc. un-shaped muscular urgim. where the fertilized ovum grows and develops.

• It is Emily covered the peritoneum mid-the cavity is lined by endometrium llieuicuis consisting of men: the hotly (expanded upper portion; the lathis (consoled rental pot lion) and the cervix.
• The ss. ill ol the Julius contains three distinct layers. The oilier thin covering ipcritoneunO is an eontinumion of die peritoneal membrane. ‘The middle link layer (myometrium) contains smooth muscles.
• The inner lining, called endometrium contains abundant blood vessels and glands to nourish and protect the embryo.
• li fertilization occurs, the early embryo burrows into this layer through a process called implantation. If fertilization and implantation, do not occur, portions of this layer are shed and replaced every month during the menstrual cycle.

Animal Reproductive System NEET Study Material

NEET Biology Animal Reproductive System Vagina

• The vagina is a flexible muscular tube extending from the cervix to the body’s exterior. The female genitalia are collectively called the vulva.
• The vulva includes two sets of fleshy folds called labia, the mons pubis, and the clitoris.
• The female reproductive system has five major functions.

1. 1. It produces and transports the female gametes and receives the sperm of the male.
   2. It provides a site for fertilization.
   3. It supports, protects, and nourishes the development of the fertilized egg, embryo, and fetus.
   4. It provides a birth canal for the newborn infant.

• In addition to these reproductive functions, the female produces milk from mammary glands to nourish the newborn child.
• The primary organs that accomplish these tasks are a pair of ovaries, a pair of uterine tubes (oviducts or fallopian tubes), a uterus, and the vagina.

NEET Biology Animal Reproductive System The Menstrual Cycle

NEET Biology Animal Reproductive System Puberty

It is the period of sexual maturity. It comes between 13 to 16 years in the male and between 10 to 14 years in the female.

It is controlled by testosterone in the male and estrogens in the female. It is characterized by the development of secondary sexual characters.

• Precocious puberty: Normally a woman’s fertile life starts from the age of puberty (about 13 years), but under some abnormal conditions like high levels of sex hormones (LH and FSH), menstruation starts at an earlier age than normal, it is called precocious puberty.
• Orgasm in females: During intercourse, under the influence of various stimuli, the female becomes excited. The clitorial and genital folds swell and the vaginal wall secretes a moist lubricating fluid.
  • The breasts swell and the nipples become erect. Orgasm is associated with the contraction of the vaginal wall. At orgasm, the cervix drops down into the upper portion of the vagina and creates a syringing action on the pool of semen.
• Parturition: It is a process of expulsion of a fetus from the uterus. It starts at the end of pregnancy. It takes place by the rhythmic contractions and propulsion movements of the uterine wall.
  • The cervix becomes soft and dilates at that time. The tire fetus is pushed down into the genital passage. Generally, the head comes out first. If legs come first then the baby is called a breech baby.
  • The period of the year when an animal may breed is called breeding season For Example autumn for sheep and spring and autumn for bitches. The estrous cycles run only’ during the breeding season in monoestrous animals.
  • The estrous cycles run throughout the year in polyestrous animals Example Cow, Buffalo.
  • The suspension of the estrous cycle in female animals throughout the non-breeding season is called the state of anoestrum.

Animal Reproductive System NEET Study Material

NEET Biology Animal Reproductive System Memory Points

• Cow and buffalo are continuously breeding animals.
• The ovum or egg is the largest cell of the body.
• Monarch. The onset of the menstrual cycle in females is termed menarche.
• Most birds possess only the left ovary and the left oviduct for conveying the ovum released from the ovary, the right ovary and right oviduct being rudimentary vestiges.
• The left oviduct leads to a swollen tube called a shell gland. When the egg reaches here through the oviduct, the shell gland deposits calcium salts on it to form the eggshell.
• Uterine milk. Nutritive endometrial secretion.
• Miscarriage or Abortion. Loss of embryo due to breakdown of endometrium due to lowering of progesterone secretion from corpus luteum.
• Colostrum. ‘I the fluid released from the nipples a few days after parturition. It is ri(h in protein globulin and low in fat. It transfers antibodies from mother to baby.
• Mali-, have high IJMK due to greater activity.
• Vitellogenesis. Synthesis of yolk in primary oocyte during prophase.
• The side of the ovum that extrudes polar bodies is known as an animal pole and the opposite side is a vegetal pole.
• In a woman’s loiillily period of 32 yours, about 13 eggs mnlurr ouch year .mil on about eggs have chance In reach maturity.
• Ovulation in human female lakes placed on Mill clay of menstrual cycle which is 28 a. 2-day cycle.
• Ovulation. Release of ovum during the menstrual cycle is due To a large concentration of 11 on the Mill day of the menstrual cycle.
• Menstrual bleeding is caused due to the reduction in concentration of both estrogen and progesterone especially progesterone During the first trimester of pregnancy, the corpus luleum secretes the progesterone hormone which maintains pregnancy.
• Chorionic gonadotropin is secreted from the placenta which is formed during pregnancy only.
• At the time of parturition (Childbirth), the hormone secreted is relaxin, which relaxes the pubic ligaments and helps in childbirth.
• The ovaries contain 2 million or more primary oocytes 6 months before birth about a million at the time of birth and only 400,000 remain by the time of puberty.

NEET Biology Animal Reproductive System Important Terms

1. Microgamete:  (sperm) small-sized, haploid, motile gamete that is deficient in stored nutrients is a tanned microgamete.
2. Macroganiete:  (Ovum or female gamete). It is large-sized, non-motile, haploid, laden with nutrients is called macrogamete.
3. Isogamy:  The fusion of similar gametes is called isogamy. e.g Monocystis.
4. Anisogamy:  The fusion of gametes that are different in form, size, and behavior is termed anisogamy, such gametes are termed heterogametes, e.g. frogs, human
5. Estrous Cycle:  It consists of a few days of estrous (heat) followed by a few days of anoestrous. There is no bleeding and endometrium is reabsorbed.
6. Semen:  It is a fluid which is usually ejaculated only after the penis has been stimulated during sexual excitement. It contains sperms (about 200-400 million per 3 ml.), secretions of various reproductive glands, fibrinogen, thromboplastin, and calcium citrate.
7. Corpus tuteum:  The ruptured Graafian follicle after ovulation is called corpus Iuteum and secrete progesterone hormone into blood.
8. Spermatic cord:  It is an elastic cord that passes through the inguinal canal and is attached to the testis.
9. The gubernaculum Mesometriun: is a fibromuscular tissue that binds the testis with the scrotal sac.
10. Sertoli cells:  Sertoli cells = Nurse cells = subtesticular cells. •
11. Graafian follicleMesometriun: discovered by Regnier de Graff.
12. Antrum:  Antrum fluid-filled space in Graafian follicle
13. Mesometriun:  Mesometriun Fold of peritoneum lining which encloses the uterus and vagina
14. Mesovarium:  Fold of the peritoneal membrane that surrounds the ovary in frog
15. Mesosalpinx:  The fold of the peritoneal membrane that surrounds the fallopian tube.
16. Mesorchium: The fold of the peritoneal membrane surrounds the testes in frogs.

In male frogs, nuptial pads are found at the metacarpals of 1st digit of the forelimb. These are also known as copulatory pads.

• The two fundamental methods of reproduction are asexual and sexual reproduction.
• Monocystis, Plasmodium, and Paramecium are acellular protists that reproduce sexually.
• Pseudopodiosporcs. During multiple fission in cysted amoeba many minute amoebae are formed termed pseudopodiospores.
• Gemmules are formed as internal buds (endogenous) covered by opaque envelopes in porifers such as Spongilla.
• Conjugation in Paramecium. It is the gametic nuclei fusion between two conjugating individuals through the cytoplasmic bridge.
• Animals with ability are termed as Hermaphrodite
  The development of an unfertilized ovum into a new individual is called parthenogenesis.
• The mature follicles are termed Graafian follicles. Rete-testis are cuboidal epithelium lined channels from which arise 10-20 fine tubules termed ductules efferent- tia.
• Mesovarium. The peritoneal membrane by which ovaries are suspended from the wall of the pelvic cavity.
• Cumulus oophorus. A heap of granulosa cells by which oocyte adheres to the wall of the follicle.
• Corpus lutcum. The granulose cells and interstitial cells form a mass of large yellowish conical cells after ovulation.
• c& Follicular atresia. Follicles in the ovaries that undergo regression and disappear due to death and are disposed of by phagocytes during the reproductive years of females are referred to as follicular atresia.
• Hormonal control of the male reproductive system  The hypothalamus has ultimate control of the testes’ sexual function because it secretes a hormone called gonadotrophic releasing hormone (GnRH) that stimulates the anterior pituitary to produce the gonadotrophic hormones.
• There are two gonadotrophic hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH), in both males and females. In males, FSH promotes spermatogenesis in the seminiferous tubules which also release the hormone inhibin. Inhibin acts to inhibit luteinizing hormone secretion by the anterior pituitary gland.

Animal Reproductive System NEET Study Material

• LH in males is sometimes given the name Interstitial cell-stimulating hormone (ICSH) because it controls the production of testosterone by the interstitial cells, scattered in the spaces between the seminiferous tubules.
• All these hormones are involved in a negative feedback relationship that maintains the constant production of sperm and testosterone.
• Testosterone is the main sex hormone in males. It is essential for the normal development and functioning of the male reproductive organs. Testosterone is also necessary for the maturation of sperm.
• Testosterone brings about and maintains the male secondary sex characteristics that develop at the time of puberty. It is responsible for the greater muscle strength of males, and this is the reason some athletes take supplemental amounts of anabolic steroids which are either testosterone or related chemicals.
• Hormonal control of the female reproductive system Mature females produce two sex hormones: estrogen and progesterone. Both are produced in the ovary by the specialized cells.

• During puberty, the anterior pituitary begins releasing LH and FSH together, L.H. and FSH stimulate the ovaries to produce estrogen and progesterone.
• Estrogen is responsible for the development of secondary sexual characteristics and for cyclic changes in the vaginal epithelium and endothelium of the uterus.
• Estrogen is also responsible for contour changes in the pelvis and the distribution of fat under the skin. Progesterone is a steroid hormone produced by the corpus lutein and placenta.
• Progesterone is responsible for changes in uterine endometrium in the second half of the menstrual cycle preparatory for the implantation of the blastocyst, development development of the maternal placenta, and implantation of mammary glands.

Hormonal Control of Menstrual Cycle. Gonadotropin-releasing hormone (GnRH) also called gonadotropin-releasing Factor (GnRF), is secreted by the hypothalamus of the brain, which stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

FSH stimulates the ovarian follicles to produce estrogens during the proliferative phase. LH stimulates the corpus luteum of the ovary to secrete progesterone.

1. The menstrual phase is caused by the reduction of progesterone and estrogens.
2. The proliferative phase is caused by the increased production of estrogens.
3. LH causes ovulation.
4. The secretory phase is caused by increased production of progesterone.

Capacitation: The sperms in the female’s genital tract are made capable of fertilizing the egg by secretions of seminal vesicles, prostate gland, and Cowper’s glands present in the semen itself. This process is called capacitation of sperms. It takes several (5 – 6) hours and involves n change in the properties of the membrane covering the acrosome.

1. Sperm lysins
2. Hyaluronidase
3. Corona penetrating enzyme
4. Fertilizin is a chemical that is released by acrosome during fertilization.

Reproductive System In Animals NEET Biology Notes 

NEET Biology Animal Reproductive System Quanta To Memory

Menstrual Cycle

• The menstrual Phase is caused by the reduction of progesterone and estrogens
• The proliferative phase is caused by increased production of estrogen
• LH causes ovulation
• The secretory phase is caused by an increase in progesterone

Fertilization 

• Physico-chemical event
• Site-Ampullary -Isthmic junction
• Insemination (single ejaculate contains 300 million sperm)
• The arrival of secondary oocyte stage
• Capacitation of sperms
• Acrosomal reactions
• Sperms Entry
• Karyogamy
• Activation of egg

Placenta

• The Chorionic Placenta Foetal part, chorion, and material part of the decidua basalis
  • Nutrition
  • Respiration
  • storage
  • Excretion
  • Barrier
• Endocrine Role- Oestrogen, progesterone, HCG Relaxin hp

NEET Biology Animal Reproductive System Questions From Competitive Examinations

Question 1. Which set is similar :

1. Corpus luteum – graafian follicles
2. Sebum – Sweat
3. Bundle of His – Pacemaker
4. Vit. B – Niacin.

Answer: 1. Corpus luteum – Graafian follicles

Question 2. The temperature of the scrotum which is necessary for the functioning of
the testis is always below body temperature. This difference is:

1. 2°C
2. 3°C
3. 4°C
4. 6°C

Answer: 1.2°C

Question 3. Bartholin glands are situated :

1. On either side of the vagina in humans.
2. On either side of the vas deferens in human
3. On the sides of the heads of some amphibians
4. At the reduced tail ends of birds.

Answer: 1. On either side of the vagina in humans.

Reproductive System In Animals NEET Biology Notes 

Question 4. The menstrual cycle is affected by :

1. Progesterone only
2. LH only
3. LH + FSH + oestrogen
4. Oestrogen only.

Answer: 3.LH + FSH + oestrogen

Question 5. The preparation of sperm before entry into the ovum is called

1. Insemination
2. Maturation
3. Capacitation
4. Fertilization.

Answer: 3. Capacitation

Question 6. The oocyte is liberated from the ovary under the influence of LH, after completing ;

1. Meiosis and before liberating polar bodies
2. Meiosis-I and before liberating polar bodies
3. Meiosis
4. Meiosis after the release of the polar body.

Answer: 4. Meiosis after the release of the polar body.

Question 7. Which is correct about human embryonic development?

1. Cleavage divisions bring about a considerable increase in the mass of protoplasm In the school division.
2. one of the two elastomers usually divides a little sooner than the second
3. With more cleavage division, the resultant blahs- come Ivconie larger and larger
4. Cleiv age division results in a hollow ball of cells called the month

Answer: 2. one of the two elastomers usually divides a little sooner than the second

Question 8. The number of chromosomes in a mature gamete gets halved during :

1. Formation of first polar body
2. Formation of second polar body
3. Meiosis 2
4. Division of secondary oocyte and spermatocyte.

Answer: 1. Formation of first polar body

Question 9. Frog’s testes do not possess :

1. Interstitial cells
2. Seminiferous tubules
3. Sertoli cells
4. Seminal vesicles.

Answer: 3. Sertoli cells

Question 10. In oogamy, fertilization involves :

1. A large non-motile female gamete and a small non-motile male gamete
2. A large motile female gamete and a small non-mo- tile male gamete
3. A small non-motile female gamete and a large motile male gamete
4. A large non-motile female gamete and a small motile male
   gamete,

Answer: 4. A large non-motile female gamete and a small motile male gamete,

Reproductive System In Animals NEET Exam Preparation

Question 11. In human females, ovulation occurs during the menstrual cycle :

1. At the end of the proliferative phase
2. In the middle of the secretory phase
3. Just before the end of the secretory phase
4. At the beginning of the proliferative phase.

Answer: 1. At the end of the proliferative phase

Question 12. Nebenkem is a part of:

1. Human ovum
2. Human sperm
3. Fetus
4. Graafian follicle.

Answer: 2. Human sperm

Question 13. Yellow-colored milk secreted by cattle soon after the birth of a calf is called :

1. Cholesterol
2. Colostrum
3. Chyme
4. Chyle.

Answer: 2. Colostrum

Question 14. In the diagram of the section of the Graafian follicle, different pans are indicated by alphabets. Choose the answer in which these alphabets have been correctly matched with the parts they indicate.

1. A =Membrana granulosa: B = Theca interna;
C = ovum; D = Cumulus rooms: E = Antrum;
F = Theca externa

2. A= Theca externa; B = Theca interna; C = ovum;
D = Mcmbrana granulosa; E = Antrum ;
F = Cumulus oophorus

3. A = Theca externa; B = Theca interna;
C = ovum; D = Cumulus oophorus; E = Antrum ;
F = mcmbrana granulosa

4. A = Membrane granulosa; B = Theca externa ;
C = Ovum ; D = Cumulus rooms ; E = Antruin ;
F =Theca interna

Answer: 3. A = Theca externa; B = Theca interna;
C = ovum; D = Cumulus oophorus; E = Antrum ;
F = mcmbrana granulosa

Question 15. Ovulation in the human female normally takes place during the menstrual cycle :

1. At the beginning of the proliferative phase
2. At the end of the proliferative phase
3. In the mid of the secretory phase
4. Just before the end of the secretory phase.

Answer: 2. At the end of the proliferative phase

Question 16. In which of the following organisms testes descend into the scrotum in the breeding season but in non-breeding season?

1. Frog
2. Kangaroo
3. Shrew
4. Bat.

Answer: 4. Bat.

Question 17. The proliferation of endometrium of the uterus is controlled by :

1. Relaxin
2. Oxytocin
3. Progesterone
4. Oestrogen
5. Luteinizing.

Answer: 4. Luteinizing.

Question 18. The type of placenta in sharks is

1. Allantoic
2. yolk sac
3. Hemophilia
4. Syndesmochorial.

Answer: 2. yolk sac

Reproductive System In Animals NEET Exam Preparation

Question 19. Which cell organelle is absent in human sperm?

1. ER
2. Mitochondria
3. Nucleus
4. Centrioles.

Answer: 1. ER

Question 20. The origin of the kidney and ureter in Rcina Grinch is

1. All mesodermal
2. All endodermal
3. Ectodermal and mesodermal
4. Mesodermal and endodermal.

Answer: 1. All mesodermal

Question 21. Which of the following is ‘immortal’?

1. Somatic cells
2. Glomerular cells
3. Genu cells
4. Cells of pituitary.

Answer: 3. Genu cells

Question 22. Grey crescent is an area :

1. At the point of entry of sperm into the ovum
2. At the animal pole
3. Just opposite to site of sperm entry into the ovum
4. At the vegetal pole.

Answer: 3. Just opposite to the site of sperm entry into the ovum

Question 23. Wolffian duct forms :

1. Epididymis
2. Oviduct
3. Ejaculatory duct
4. Urethra.

Answer: 1. Epididymis

Question 24. A cross-section at the midpoint of the middle piece of a human sperm will show:

1. Centriole, mitochondria and 9 + 2 arrangement of microtubules
2. Centriole and mitochondria
3. Mitochondria and 9 + 2 arrangement of microtubules
4. 9 + 2 arrangement of microtubules only.

Answer : 3. Mitochondria and 9 + 2 arrangement of microtubules

Question 25. Which one of the following events is coevally inches with the lime period in a normal menstrual cycle?

1. Release of egg = 5 days
2. Endometrium regenerate = 5-1O days
3. Endometrium secretes nutrients for implantation:11-18days
4. Rise in progesterone:1-15days

Answer: 3. Endometrium secretes nutrients for implantation:11-18days

Reproductive System In Animals NEET Previous Year Questions

Question 26. if the mammalian ovum fails to be fertilized, which one of the following is unlikely?

1. Corpus him will disintegrate
2. Hsitogen secretion I’m decreases
3. Primary follicle starts developing
4. Progesterone secretion rapidly declines.

Answer: 3. Primary follicle starts developing

Question 27. In which one of the following sets of animals do all four give birth to young ones?

1. Lion. hat. whale, ostrich
2. Platypus, penguin, bat, hippopotamus
3. Shrew, bat. cat, kiwi
4. Kangaroo, hedgehog, dolphin, loris.

Answer: 4. Kangaroo, hedgehog, dolphin, loris.

Question 28. Roth corpus lutcum and macula lutea are :

1. Found in human ovaries
2. A source of hormones
3. Characterized by a yellow color
4. Contributory in maintaining pregnancy.

Answer: 3. Characterised by a yellow color

Question 29. Sertoli cells are regulated by (the pituitary hormone known as:

1. LSI
2. GII
3. Prolactin
4. LI I.

Answer: 1. LSI

Question 30.Withdrawal of which of the following hormones is the immediate cause of menstruation?

1. Estrogen
2. FSH
3. FSH-RII
4. Progesterone

Answer: 4. Progesterone

Reproductive System In Animals NEET Previous Year Questions

Question 31. In the cloning of cattle, a fertilized egg is taken out of the mother’s womb, and :

1. In the eight-cell stage, cells are separated and cultured until small embryos are formed which are implanted into the womb of other cows.
2. In the eight-cell stage, the individual cells are separated under an electrical field for further development in culture media.
3. From this upload eight identical twins can be produced
4. Die egg is divided into 4 pairs of cells which are implanted into the womb of other cows. ‘

Answer: 1. In the eight-cell stage, cells are separated and cultured until small embryos are formed which are implanted into the wombs of other cows.

Question 32. In the human female, menstruation can be deferred by die administration of:

1. Combination of FSH and LH
2. Combination of estrogen and progesterone
3. FSH only
4. LH only

Answer: 2. Combination of estrogen and progesterone

Question 33. In humans, at the end of the first meiotic division, the male germ cells differentiate into the :

1. Spermatids
2. Spetmnlogniiili
3. Ptimiity spcim.isocyclic
4. Secondly spcimaiocylcH.

Answer: 4. Secondnty spcimaiocylcH.

Question 34. Which of the following sliilemeiil’. is incorrect about nicnslriinlion?

1. The menstrual fluid can easily clot
2. During normal menstruation about 40 ml. of blood is lost
3. The beginning of the cycle of incnslrucation is called menarche
4. At menopause in the female, there is an especially abrupt increase in gonadotropic hormones.

Answer: 1. The menstrual fluid can easily clot

Question 35. Which one of the following statements about human sperm is correct?

1. The sperm lysins in the acrosome dissolve the egg envelope
   facilitating fertilization.
2. Acrosomc serves as a sensory structure leading the sperm toward the ovum
3. Acrosomc serves no particular function
4. Acrosomc has a conical pointed structure used for piercing and penetrating the egg, resulting in fertilization.

Answer: 4. Acrosomc has a conical pointed structure used for piercing and penetrating the egg, resulting in fertilization.

Question 36. The signals for parturition originate from :

1. Placenta as well as a fully developed fetus
2. Oxytocin released from the maternal pituitary
3. Fully developed fetus only
4. Placenta only.

Answer: 1. Placenta as well as fully developed fetus

Reproductive System In Animals NEET Previous Year Questions

Question 37. Sertoli cells are found in :

1. The adrenal cortex secretes adrenaline
2. Seminiferous tubules provide nutrition to germ cells
3. Pancreas and secrete cholecystokinin
4. Ovaries and secrete progesterone.

Answer: 2. Seminiferous tubules and provide nutrition to germ cells

Question 38. Which of the following is characteristic of the 27th day of the menstrual cycle?

1. Stasis of blood in the basal straight arteries of the endometrium
2. Constriction of the coiled spiral arteries
3. Increased proliferation of the endometrium
4. Increased edema of the functional spongy layer of the endometrium.

Answer: 2. Constriction of the coiled spiral arteries

Question 39. In the male reproductive system :

1. Spermatozoa pass in order through efferent ductules, rete testis,
   and ductus epididymis.
2. The ductus deferens, seminal vesicle, and prostate- all have smooth muscle in their walls.
3. the seminal vesicle is the main source of acid phosphatase in the semen
4. The prostate gland is a site where the maturation of sperm occurs.

Answer: 2. The ductus deferens, seminal vesicle, and prostate- all have smooth muscle in their walls.

Question 40. The figure given below depicts a diagrammatic sectional view of the female reproductive system of humans. Which one set of three parts out of I-Vl have been correctly identified?

1. (2) Endometrium. (3) Infundibulum, (4) Fimbriae
2. (4) Ovitlucal funnel, (5) Utenis, (6) Cervix
3. (3)Infundibulum, (4) Fimbriae, (5) Cervix
4. (1) Perimetrium,(2) Myometrium. (3) Fallopian lube.

Answer: 3. (3)Infundibulum, (4) Fimbriae, (5) Cervix

Question 41. The testes in humans are situated outside the abdominal cavity inside a pouch called the scrotum. The purpose served is for:

1. Maintaining the scrotal temperature lower than the internal body temperature
2. Escaping any possible compression by the visceral organs
3. Providing more space for the growth of epididymis
4. Providing a secondary sexual feature for exhibiting the male sex.

Answer: 1. Maintaining the scrotal temperature lower than the internal body temperature

Question 42. If for some reason, the vasa efferentia in the human reproductive system get blocked, the gametes will not be transported from :

1. Ovary to uterus
2. Epididymis to vas deferens
3. Testes to epididymis
4. Vagina to the uterus.

Answer: 3.Testes to epididymis

Question 43. The luteal (secretory) phase of the menstrual cycle is characterized by all of the following:

1. Coiling or sacculation of endometrial glands
2. Decreased amounts of progesterone in the blood plasma
3. The presence of a functional corpus luteum
4. Atresia of some ovarian follicles.

Answer: 3. The presence of a functional corpus luteum

Question 44. The first movements of the fetus and the appearance of hair on its head are usually observed during which month of pregnancy?

1. Fifth month
2. Sixth month
3. Third month
4. Fourth month.

Answer: 1. Fifth month

Question 45. Hie second maturation division of the mammalian ovum occurs:

1. Until after the ovum has been penetrated by a sperm
2. Until the nucleus of the sperm has fused with that of the ovum
3. In the Graafian follicle following the first maturation division
4. Shortly after ovulation, the ovum makes entry into the fallopian tube.

Answer: 1. Until after the ovum has been penetrated by a sperm

Question 46. Which one of the following statements about morula in humans is correct?

1. It has far less cytoplasm as well as less DNA than an uncleaved
   zygote.
2. It has more or less an equal quantity of cytoplasm and DNA as in
   uncleaved zygote.
3. It has more cytoplasm and more DNA than an uncleaved zygote.
4. iDl It has an almost equal quantity of cytoplasm as an uncleaved zygote
   but much more DNA

Answer: 1. It has far less cytoplasm as well as less DNA than an uncleaved zygote.

Question 47. During the  (sperm to- genesis), the awesome arises by the accumulation of material in :

1. Mitochondria
2. The nucleus
3. The Golgi complex
4. The nuclear envelope.

Answer: 3. The Golgi complex

Question 48. Seminal plasma in human males is rich in :

1. Glucose and calcium
2. DNA and testosterone
3. Ribose and potassium
4. Fructose and calcium.

Answer: 4. Fructose and calcium.

Question 49. What is correct to say about the hormone action in humans?

1. Secretion of thymosin is stimulated with aging.
2. In females, FSH first binds with specific receptors on the ovarian cell membrane.
3. FSH stimulates the secretion of estrogen and progesterone.
4. Glucagon is secreted by P-cells of Islets of Langerhans and stimulates glycogenolysis.

Answer: 2. In females, FSH first binds with specific receptors on the ovarian cell membrane.

Question 50. In a normal pregnant woman, the amount of total gonadotropin activity was assessed. The result expected was:

1. High level of circulating HCG to stimulate endometrial thickening.
2. High levels of FSH and LH in the uterus stimulate endometrial thickening.
3. High level of circulating HCG to stimulate estrogen and progesterone synthesis.
4. High levels of circulating FSH and LH in the uterus stimulate the implantation of the embryo.

Answer: 1. High level of circulating HCG to stimulate endometrial thickening.

Question 51. Signals for parturition originate from :

1. Oxytocin released from the maternal pituitary
2. Placenta only
3. The fully developed fetus only
4. Both placenta as well as fully developed fetus.

Answer: 4. Both placentas as well as the fully developed fetus.

Question 52. The Leydig’s cells as found in the human body are the secretory sources of:

1. Intestinal mucus
2. Glucagon
3. Androgens
4. Progesterone.

Answer: 3. Androgens

Question 53. Which one of the following is not the function of the placenta? It:

1. Secretes estrogen
2. Facilitates removal of carbon dioxide and waste material from embryo
3. Secretes oxytocin during parturition
4. Facilitates supply of oxygen and nutrients to the embryo.

Answer: 3.Secretes oxytocin during parturition

Question 54. What is the correct sequence of sperm formation ?

1. spermatogonia, spermatocyte, spermatozoa, spermatid
2. Spermatogonia, spermatozoa, spermatocyte, spermatid
3. Spermatogonia, spermatocyte, spermatid, spermatozoa
4. Spermatid, spermatocyte, spermatogonia, spermatozoa

Answer: 3.Spermatogonia, spermatocyte, spermatid, spermatozoa

NEET Biology Animal Reproduction Reproductive System Multiple Choice Questions

Question 1. The ovary is an organ of:

1. Male reproductive system
2. Female reproductive system
3. Male excretory system
4. Female excretory system.

Answer: 2. Female reproductive system

Question 2. The oviducal funnel in frogs is situated near the :

1. Base of ovary
2. Base of lung
3. Oesophagus
4. Lop of the ovary.

Answer: 3. Oesophagus

Question 3. Ripe ova arc sited by ovaries into :

1. Oviducal funnel
2. Coelom
3. Oviduct
4. Collecting tubules of kidney.

Answer: 2. Coelom

Read and Learn More NEET Biology Multiple Choice Question and Answers

MCQ on Male Reproductive System for NEET Question 4. The proliferative phase lasts for :

1. 2 days
2. 10-12 days
3. 28 days
4. only one week.

Answer: 2.10-12 days

Question 5. The secretory phase consists of:

1. 1-week duration
2. 12-14 days’ duration
3. 15-20 days’ duration
4. 28 days’ duration.

Answer: 2.12-14 days’ duration

Question 6. Front each testis of frog arise about a dozen, small, delicate tubules called :

1. Vasa deferentia
2. Vasa efferentia
3. Ureters
4. Bidder’s canal.

Answer: 2. Vasa efferentia

Question 7. Corpus adipose refers to:

1. Phase of oogenesis
2. The fat layer of the skin
3. Reserve fat
4. Fat portions of the testis.

Answer: 3. Reserve fat

Question 8. Bidder’s canal is found in :

1. Liver
2. Kidney
3. Gall bladder
4. Spleen.

Answer: 2. Kidney

Question 9. Gametes are produced by (the process of gametogenesis in cells called :

1. Germinal epithelial cells
2. Germinal epidermal qe|ls
3. Germinal ectodermal cells
4. Germinal endodermal cells.

Answer: 1. Germinal epithelial cells

MCQ on Male Reproductive System for NEET Question 10. Germ cells or gametes of all vertebrates are called :

1. Ovules and sperms
2. Ova and spermatozoa
3. Ova and pollen
4. None of these.

Answer: 2. Ova and spermatozoa

Question 11. In the testis, primary germinal cells undergo mitotic divisions to produce :

1. Spermatozoa
2. Primary spermatocyte
3. Spermatogonia
4. Secondary spermatocyte.

Answer: 3. Spermatogonia

Question 12. In the process of gametogenesis in the testes, meiotic division takes place in the:

1. Primary spermatocyte
2. Secondary spermatocyte
3. Spermatogonium
4. Primary germ cell

Answer: 1. Primary spermatocyte

Question 13. Each testis is packed with :

1. Sperms
2. Seminiferous tubules
3. Spermatogonia
4. Spermatocytes.

Answer: 3. Seminiferous tubules

Question 14. The Bidder’s canal in frog helps to pass out :

1. Ova
2. Sperms
3. Bile
4. Saliva.

Answer: 2. Sperms

MCQ on Male Reproductive System for NEET Question 15. Cells of Leydig are found in :

1. Ovary
2. Testis
3. Prostate
4. Liver.

Answer: 2. Testis

Question 16. In a transverse section, a frog’s testis differs from that of a human’s testis in the:

1. Absence of Sertoli cells
2. Position of heads of spermatids
3. Seminiferous tubules
4. All the above.

Answer: 4. All the above.

Question 17. In which part of the female reproductive system of frogs, eggs are stored temporarily before spawning?

1. Oviduct
2. Ureter
3. Uterus
4. Ovisac.

Answer: 4. Ovisac.

Question 18. In frogs, the spermatozoa pass through which duct?

1. Mullerian duct 1
2. Vas deferens
3. Wolffian duct
4. Vasa efferentia.

Answer: 3. Wolffian duct

Question 19. The oviduct in the frog is actually :

1. Mullerian duct
2. Bidder’s canal
3. Wolffian duc^
4. Vagina.

Answer: 1. Mullerian duct

Reproductive System MCQ  Question 20. The membrane which holds, the ovary in position is called:

1. Mesorchium
2. Mesovarium
3. Parietal peritoneum
4. Qiesosalpinx.

Answer: 2. Mesovarium

Question 21. In humans, the glandular tissue of each breast is divided into how many mammary lobes :

1. 5-10
2. 11-15
3. 50-100
4. 15-20.

Answer: 4.15-20.

Question 22. Sperms and Ova develop from :

1. Ectoderm
2. Mesoderm
3. Endoderm
4. Ectoderm and mesoderm.

Answer: 2 . Mesoderm

Question 23. The cells of germinal epithelium in the gonads are of the following types :

1. Columnar
2. Cuboidal
3. Squamous
4. Stratified.

Answer: 2. Cuboidal

Question 24. Spermatogonia undergoes a growth phase to become :

1. Spermatozoa
2. Spermatids
3. Primary spermatocyte
4. Secondary spermatocyte.

Answer: 3. Primary spermatocyte

Reproductive System MCQ  Question 25. The gelatin coat of the frog’s egg keeps it:

1. Cool
2. Moist
3. Warm
4. Safe and provides buoyancy.

Answer: 4. Safe and provides buoyancy.

Question 26. The egg of frog can I’c dcwcrilvd as:

1. Microlceilhal
2. Mesolcvithal and telolecilhal
3. Aenhvkvithal
4. Alecilhal.

Answer: 2.Mesolcvithal and telolecilhal

Question 27. Spermatozoa air is found by the process of:

1. Fission
2. Mitotic division
3. Spermatogenesis
4. Oogenesis.

Answer: 3. Spermatogenesis

Question 28. Menstrual flow occurs due to a lack of:

1. FSH
2. Oxytocin
3. Progesterone
4. Vasopressin

Answer: 3. Progesterone

Question 29. Testosterone, a honnonc responsible for the development of secondary sex characteristics of the male, is produced by the :

1. Seminiferous tubule
2. Anterior lobe of the pituitary
3. Cells that lie between the seminiferous tubules
4. Spermatogonia.

Answer: 3. Cells that lie between the seminiferous tubules

Question 30. The first meiotic division in the oogonium is completed when the egg is within the :

1. Uterus
2. Follicle
3. Fallopian tube
4. Ovary, before it is surrounded by follicles.

Answer: 2. Follicle

Reproductive System MCQ  Question 31. If an unfertilized frog’s egg is pricked with a microneedle. it will:

1. Die immediately
2. Stan dividing
3. Will remain undivided
4. Transform into a tadpole at a faster rate.

Answer: 2. Stan dividing

Question 32. The development of an egg without fertilization is called :

1. Gametogenesis
2. Metamorphosis
3. Oogenesis
4. Parthenogenesis.

Answer: 4. Parthenogenesis.

Question 33. The female rabbit is :

1. Natural ovulation
2. Seasonal ovulation
3. Spontaneous ovulation
4. Induced ovulatory.

Answer: 4. Induced ovulation.

Question 34. Progesterone is secreted by :

1. Testis
2. Ovary
3. Uterus
4. Vagina.

Answer: 2. Ovary

Question 35. Graafian follicle is found in :

1. Thyroid of rabbit
2. Ovary of rabbit
3. Testis of rabbit
4. kidney of the frog.

Answer: 2. Ovary of rabbit

Reproduction in Animals MCQ Biology Question 36. The primary sex cells contain :

1. Haploid genome
2. Diploid genome
3. As many chromosomes as in sperm
4. As many chromosomes as in the ovum.

Answer: 2. Diploid genome

Question 37. The seminal vesicle or uterus masculinist in rabbits is found at the junction of :

1. Prostate and Cowper’s glands
2. Prostate and urethra
3. Prostate and vas deferens
4. Vas deferens and testis.

Answer: 3. Prostate and vas deferens

Question 38. Which of the following is a hermaphrodite?

1. Ani
2. Earthworm
3. Aphid
4. Trout.

Answer: 2. Earthworm

Question 39. Primary spermatocyte refers to :

1. Sperm before second division
2. Sperm after first micturition division
3. Spermatogonium which ceases division and starts growing
4. Primordial sex cells.

Answer: 3. Spermatogonium which ceases division and starts growing

Question 40. The awesome plays an important role in :

1. Motility of sperm
2. Penetration of ovum by sperm
3. The fusion of pronuclei of the gametes
4. None of the above.

Answer: 2. Penetration of the ovum by sperm

Question 41. In frogs pseudocopulation occurs since the penis is absent in the male and fertilization of the egg occurs :

1. Externally in the water
2. Inside the Bidder’s canal
3. When the egg passes through the uterus
4. When the egg is in the cloaca.

Answer: 1. Externally in the water

Reproduction in Animals MCQ Biology Question 42. In frogs the sperms released from the testis take the following route to reach the Wolffian duct:

1. Vasa efferentia, Bidder’s canal, uriniferous tubule and nephrostome
2. Vasa efferentia, Bidder’s canal, and collecting tubule
3. Vasa efferentia, uriniferous tubule, and Bidder’s canal
4. Vasa deferentia, uriniferous tubule, and Bidder’s canal.

Answer: 2. Vasa efferentia, Bidder’s canal and collecting tubule

Question 43. The vegetal hemisphere of a frog’s egg contains yolk. It remains directed :

1. Downwards
2. Leftwards
3. Upwards
4. To the right side.
5. Answer: 1. Downwards

Question 44. Upward-directed pigment part of the frog’s egg contains living cytoplasm. It is related to:

1. Respiration
2. Coloration
3. Camouflage
4. Nourishment.

Answer: 3. Camouflage

Question 45. In the male rabbit, testes are located in :

1. Extra abdominal scrotal cavity
2. Abdominal cavity
3. Thoracic cavity
4. Pericardial cavity.

Answer: 1. Extra abdominal scrotal cavity

Question 46. Amnion is an extra-embryonic membrane which develops during the embryonic development in :

1. Cockroach
2. Lizard
3. Frog
4. Fish.

Answer: 2. Lizard

Question 47. External fertilization occurs almost exclusively in habitats that are:

1. Tropical
2. Warm
3. Moist
4. Crowded.

Answer: 3. Moist

Reproduction in Animals MCQ Biology Question 48. The center of the primary follicle is occupied by :

1. Follicular cells
2. Oogonium
3. Theca Interna
4. None of the above.

Answer: 2. Oogonium

Question 49. The secondary follicle differs from the primary follicle in that: .

1. The primary follicle has only a single layer of flattened cells around the oogonium
2. The secondary follicle has cuboidal columnar and stratified epithelium around the oogonium
3. The oocyte within the secondary follicle is covered by a thick membrane called zona pellucida
4. All the above.

Answer: 4. All the above.

Question 50. Cumulus oophorus refers to:

1. A heap of oocytes found in the secondary follicle
2. Heap of follicular cells around the ovum in the primary follicle
3. Hill of follicular cells that contain the ovum in the secondary follicle
4. None of the above

Answer: 3. Hill of follicular cells that contain the ovum in the secondary follicle

Question 51. What are two types of cells seen in the die seminiferous tubule?

1. Germinal epithelial cells and cells of Sertoli
2. Cells of Lcydig and Reie cells
3. Stcrcociliarv cells and cuboidal cells
4. Gonocytcs.

Answer: 1. Germinal epithelial cells and cells of Sertoli

MCQ on reproductive system with answers  Question 52. In a section of the testis. the groups of cells seen scattered between seminiferous tubules are :

1. Cells of Sertoli
2. Gonocytcs
3. Interstitial cells
4. Stereociliary cells.

Answer: 3. Interstitial cells

Question 53. Septa which extend inward from the tunica albuginea separate the testes into compartments that contain:

1. Epididymis
2. Rete testes
3. Seminiferous tubules
4. Cells of Leydig.

Answer: 3. Seminiferous tubules

Question 54. How many layers does the muscle coat of the oviduct have?

1. One—Longitudinal
2. Two—Inner circular and outer longitudinal
3. Three—Oblique fibers in addition to the above
4. None of the above.

Answer: 2. Two—Inner circular and outer longitudinal

Question 55. Which hormone is responsible for the rupture of the follicle and initiating the formation of the corpus luteum?

1. Follicle-stimulating hormone
2. Luteotropin
3. Luteinizing hormone
4. All the above.

Answer: 3. Luteinizing hormone

Question 56. An atretic follicle is :

1. Also known as corpus albicans
2. That follicle that fails to mature and degenerates
3. That follicle which has released the ovum
4. None of the above.

Answer: 2. That follicle that fails to mature and degenerates

MCQ on reproductive system with answers  Question 57. The single layer of germinal epithelium covering the ovary is composed of:

1. Squamous cells
2. Cuboidal cells
3. Columnar cells
4. None of the above.

Answer: 2. Euboidal cells

Question 58. The layer immediately interior to the tunica albuginea which forms part of the cortex has a higher proportion of:

1. Intercellular substance
2. Connective tissue cells and fibers
3. Both and
4. None of the above.

Answer: 2. Connective tissue cells and fibers

Question 59. Match the reproductive organs on the right with the description on the left.

1. (1-a). (2-b), (3-d). (4-f),(5-c). (6-e),(7-c)
2. (13) (1-a), (2-f). (3-d), (4-c), (5-e). (6-d), (7-h)
3. (1-a). (2-f), (3-c), (4-b), (5-a), (6-b), (7-d)
4. (l-j), (2-i), (3-c). (4-b), (5-a), (6-f),(7-h).

Answer: 4. (l-j), (2-i), (3-c). (4-b), (5-a), (6-f),(7-h).

Question 60. How many mature eggs are typically produced by each ovary of a non-pregnant woman each year?

1. 52
2. 24
3. 12
4. 6.

Answer: 4.6

MCQ on reproductive system with answers  Question 61. Cryptorchidism is a condition in which testes are :

1. Surgically removed
2. Not developed in the fetus
3. Unable to produce sperm
4. Unable to descend into the scrotum.

Answer: 4. Unable to descend into the scrotum.

Question 62. A common method of asexual reproduction is by :

1. Regeneration
2. Budding
3. Archetypes
4. Gemmulation.

Answer: 2. Budding

Question 63. The female equivalent of the glans of the penis is the :

1. Vestibule
2. Clitoris
3. Hymen
4. Urethra.

Answer: 2. Clitoris

Question 64. hCG, hPL, and relaxin are produced in women.

1. At the time of puberty
2. Only during pregnancy
3. Before puberty
4. At the time of menopause

Answer: 2. Only during pregnancy

Question 65. Fertilization, embryonic development, etc, occur in frogs in :

1. Uterus
2. Fallopian tube
3. Water
4. The upper part of the oviduct.

Answer: 3. Water

Question 66. Release of the oocyte from the ovary of a rabbit is termed :

1. Implantation
2. Ovulation
3. Gestation
4. Parturition.

Answer: 2. Ovulation

Question 67. The human uterus is :

1. Paired with well-separated oviducts
2. Single large chamber with posterior part of oviduct fused to it anteriorly
3. Paired with partially fused oviducts
4. A single large chamber with completely fused oviducts.

Answer: 2. Single large chamber with the posterior part of the oviduct fused to it anteriorly

Reproductive System MCQ  Question 68. Fertilization in rabbits, man, and other placental mammals takes place in :

1. Ovary
2. Uterus
3. Fallopian tubes
4. Vagina.

Answer: 3. Fallopian tubes

Question 69. When released from the ovary, the human egg contains :

1. One Y chromosome
2. Two X chromosomes
3. One X chromosome
4. XY chromosome.

Answer: 3. One X chromosome

Question 70. The oviducts in the body of a vertebrate arc are also referred to as:

1. Mullerian duct
2. Urinogcnital duct
3. Wolffian fuel
4. Mesonephric duct.

Answer: 1. Mullerian duct

Question 71. Spawning is another term for :

1. Oviposition
2. Hatching
3. Copulation
4. Fertilization.

Answer: 1. Oviposition

Question 72. Corpus albicans is:

1. Whitish scar in the ovary of a mammal
2. Tough connective tissue coaling on testes of frog
3. Whitish subcutaneous tissue in mammals
4. Lough connective tissue coating on testis of mammals.

Answer: 1. Whitish scar in the ovary of a mammal

Question 73. The actual genetic part of a sperm is :

1. Tail
2. Middle piece
3. Head
4. The whole of it.

Answer: 3. Head

Question 74. Human eggs are :

1. Microlecithal
2. Alecithal
3. Head
4. Mesolecilhal.

Answer: 2.Alecithal

Reproductive System MCQ  Question 75. Locations of Lcydig’s cells and the secretion they produce are :

1. Ovary, estrogen
2. Liver, Cholesterol
3. Testis, testosterone
4. Pancreas, glucagon.

Answer: 2. Liver, Cholesterol

Question 76. Spermatozoa were observed for the first time by :

1. Haeckel
2. Leeuwenhoek
3. Pasteur
4. Lister.

Answer: 2. Leeuwenhoek

Question 77. Amphimixis refers to :

1. Union of male and female gametes
2. The path followed by sperm in the egg after its entry
3. Union of male and female pronuclei
4. Turning of the head of sperm by 180′.

Answer: 3. Union of male and female pronuclei

Question 78. In reproduction of a test tube baby :

1. Fertilization is done outside the body
2. The fetus is grown in a test tube
3. Fertilization is done inside the body
4. None of the above.

Answer: 1. Fertilization is done outside the body

Question 79. Which of the following statements is correct?

1. Eggs of Amphioxus are mesolecilhal and isolecithal
2. Eggs of reptiles are Meiolecitha! and Polylecithal
3. Eggs of frog are microlecithal and telolecilhal
4. Eggs of hen are microlecithal.

Answer: 2. Eggs of reptiles are Meiolecitha! and Polylecithal

Question 80. What is characteristically absent in a frog’s ovary?

1. Follicular epithelium
2. Ovarian follicle
3. Corpus museum
4. Proteinic yolk.

Answer: 3. Corpus museum

Question 81. Parthenogenesis is very common in :

1. Apis
2. Pheretitna
3. Scoliodon
4. Spider.

Answer: 1. Apis

Reproductive System MCQ  Question 82. Each potential gamete-forming cell in diploid organisms produces four gametes (functional and non-functional). The gametes of these organisms have the ;

1. Same number of chromosomes as in body cells
2. Double the number of chromosomes as in body cells
3. Half the number of chromosomes as in body cells
4. One-fourth the number of chromosomes as in body cells.

Answer: 3. Half the number of chromosomes as in body cells

Question 83. The purpose of the acrosome is :

1. To protect the sperm nucleus
2. To secrete certain enzymes which dissolve the sperm cell wall so that the nucleus can escape and fertilize the ovum
3. To secrete certain enzymes which dissolve the  egg membrane, thus facilitating the entry of the sperm into the ovum
4. None of the above.

Answer: 3. To secrete certain enzymes that dissolve the egg membrane, thus facilitating the entry of the sperm into the ovum

Question 84. The portion of the sperm known as its powerhouse is the:

1. Head
2. Neck
3. Middle piece
4. Tail.

Answer: 3. Middle piece

Question 85. The immediate predecessors of spermatids are the ;

1. Spermatogonia
2. Primary spermatocytes
3. Secondary spermatocytes
4. Sperm mother cells.

Answer: 3. Secondary spermatocytes

Question 86. The process of differentiation of spermatid into a spermatozoa is known as :

1. Spermatogenesis
2. Sperntiogenesis
3. Gametogenesis
4. Oogenesis.

Answer: 2.Sperntiogenesis

Question 87. Spermatogenesis is a sequence of events. Give the correct order :

1. Germinal epithelial cell-spermatogonium-primary Spermatocytc-2 secondary spermatocytes-4 spermatids-4 spermatozoa
2. Germinal epithelial cell- primary spermatocyte- spermatogonium -2 secondary spermatocytes-4 spermatids-4 spermatozoa
3. Germinal epithelial cell-primary spermatocyte- spermatogonium-2 secondary spermatocyte- spermatozoa-4 spermatids
4. Germinal epithelial cell-spermatogonium primary spermatocyte-2 secondary spermatocytes 4 spermatozoa-4 spermatids,

Answer: 1. Germinal epithelial cell-spermatogonium-primary Spermatocytc-2 secondary spermatocytes-4 spermatids-4 spermatozoa

Question 88. Primary spermatocyte produces 4 spermatozoa, but primary oocyte produces :

1. 1 ovum
2. 2 ova
3. 3 ova
4. 4 ova.

Answer: 1. 1 ovum

Question 89. Ovulation takes place :

1. 2 weeks before the start of the next menstrual cycle
2. 14th day of the 28-day cycle
3. 10 days after the cease of the previous monthly cycle
4. All the above are correct.

Answer: 4. All the above are correct.

Reproduction in Animals MCQ Biology Question 90. Humans are :

1. Viviparous
2. Asexually
3. Reproducing
4. Both and

Answer: 4 . Both and

Question 91. In adults each testis measures :

1. 5 to 6 cm width and 2 to 3 cm length
2. 2-3 cm width and 4 to 5 cm length
3. 4-5 cm width and 2 to 3 cm length
4. 2-3 cm width and 5 to 6 cm length

Answer: 2.2-3 cm width and 4 to 5 cm length

Question 92. Each testis is oval and has how many testicular lobules?

1. 200
2. 250
3. 2
4. 125 in each

Answer: 2.250

Question 93. The correct path Of sperms from testis to oiciIn a by corpus spongiosum duel is:

1. Vas efferintia -Rate testes-Vas deferens
2. Vas deferens-Rate testes-epididymis
3. Vas efferentia-Rate testes -epididymis
4. Rate testes – Rate testes -epididymis

Answer: 4.Rate testes – Rate testes -epididymis

Question 94. lire male accessory glands include paired seminal vesicles, a prostate, and a paired bulbourethral gland. The secretion of seminal plasma is rich in :

1. Fructose
2. Calcitonin
3. Calcium
4. Both and

Answer: 4. Both and

Question 95. Primary female reproductive organs tire :

1. Oviducts
2. Ovaries
3. Mammary gland
4. Cervix

Answer: 2. Ovaries

Question 96. The edges of the infundibulum possess finger-like processes called:

1. Cervix
2. Mons pubis
3. Fimbriae
4. Ampulla

Answer: 3. Fimbriae

Reproduction in Animals MCQ Biology Question 97. Fertilization in humans takes place in the:

1. Fallopian tube
2. Ampulla
3. Isthmus
4. Ampulla-isthmus junction

Answer: 4. Ampulla-isthmus junction

Question 98. The cells of the alveoli of mammary glands secrete milk and store it in the lumen of these lobules (alveoli). The breast is divided into how many mammary lobes?

1. 200
2. 250
3. 15-20
4. 120-150

Answer: 3.15-20

Question 99. How many eggs are released by each ovary in one year?

1. 2
2. 6
3. 12
4. 4

Answer: 2.6

Question 100. The menstrual cycle stops after :

1. Gestation period
2. Lactatational
3. 45-50 years of age
4. All of above

Answer: 4. All of the above

Question 101. Acmsotue of sperm has modified :

1. Golgi bodies
2. Lysosomes
3. FR
4. Mitochondria

Answer: 1. Glolgi bodies

Question 102. Sertoli cells are regulated by which hormone of the pituitary.

1. G I I
2. Prolactin
3. LII
4. FSH

Answer: 4. FSH

Reproduction in Animals MCQ Biology Question 103. The internal cavity formed by cell division before gastrula is:

1. Antrum
2. Enter on
3. Archcnteron
4. Blastococl

Answer: 4. Blastococl

Question 104. The part of the fallopian tube closer to the ovary is:

1. Isthmus
2. Infundibulum
3. Cervix
4. Ampulla

Answer: 2. Infundibuluom

Question 105. Release of mature sperms from Sertoli cells of seminiferous tubules is called :

1. Spermatogenesis
2. Spermiogenesis
3. Spermioteliosis
4. Spermiation

Answer: 4. spermiation

Question 106. At puberty how many primary follicles are left in the two ovaries?

1. 60,000-80,000
2. 80,000-1 lac
3. 120,000-160,000
4. 480

Answer: 1.60,000-80,000

Question 107. LH and FSH attain a peak on which day in a 28-day menstrual cycle?

1. 17th day
2. 14th day
3. 25th day
4. 5th day

Answer: 2.14th day

Question 108. 1st polar body is formed at which stage of Oogenesis?

1. 1st meiosis
2. 2nd meiosis
3. 1st mitosis
4. Differentiation

Answer: 1.1st meiosis

Question 109. In humans, the unpaired male reproductive structure is :

1. Seminal vesicle
2. Prostate gland
3. Bulbourethral gland
4. Vasa deferentia

Answer: 2. Prostate gland

NEET Biology Sexual Reproduction In Plants

• Angiosperms are the most common vascular plants on Earth. The plant body is sporophyte, differentiated into true roots, stems and leaves. A flower is a reproductive organ. Stamen (part) has 2 anthers, and 4 pollen sacs, each pollen sac has tapetum and pollen mother cells. They produce haploid microspores (pollen grains) by microsporogenesis
• Carpel (part), the ovary possesses an ovule, and each ovule has two integuments, a nucellus and one megaspore mother cell. 4 haploid megaspores are produced by megasporogenesis.
• The main function of the flower includes the production of pollen grain and ovule, pollination, fertilization, development and dispersal of seeds and fruits.
• Embryology
• It is the study of the development of the embryo.
• It includes sporogenesis, fertilization and embryo formation. Sporogenesis. It is a mode of spore formation and involves meiosis. It is of two types microsporogenesis in the pollen sac of anther and megasporogenesis inside the ovule.
• Microsporogenesis. The mature anther is a two-lobed structure. It has four pollen sacs or microsporangia. The cavity of the microsporangium encloses a large number of The life cycle of an Angiospermic plant.

Read and Learn More NEET Biology Notes

• Encloses huge Mumbai to Microsoft mother cells, they are diploid. They undergo meiosis and each one of them produces 4 haploid cells or microspores that are arranged in distinct groups to tout or tetrad.
• These groups are surrounded by a common wall of spore mother cell, these microspores develop their wall within tetrad and later separate.

NEET Biology Sexual Reproduction In Plants Pollen Grain (Microspore)

It typically has a circular shape with a wall and an interior consisting of 2 to 3 cells. The wall comprises two layers: an exterior thick exline of spuropollenin and an interior thin inline of pectocellulose. Sporopollenin is an extremely durable lipidic compound associated with cutin. The exine is categorized into the inner endexine and the outer Kleine.

Sexual Reproduction In Flowering Plants NEET Notes

Ektexine is formed of three layers

1. Inner continuous foot layer
2. Middle discontinuous bacula layer and
3. Outer discontinuous tectum.

The tectum and bacula layers produce designs over the surface of the pollen grain. Exine is absent in certain areas called germ pores (if rounded) or germinal furrows (if elongated). Depending upon their number, the pollen grains are monocolpate, bioplate, tricolpate, etc.

• In monocots, the pollen grains generally possess one germinal furrow (monocolpate) while in dicots the pollen grains have generally three germ pores (tricolpate). The sculpturing, number and position of germ pores are characteristics of each species.
• The branch dealing with the study of pollen grain characteristics is known as palynology. Insect disseminated pollen grains have a covering of a yellow sticky substance called pollen kit. Internally the pollen grain has (/) tube or vegetative cell with a degenerating nucleus, vacuolate cytoplasm rich in starch and unsaturated oil and (n) one generative cell or two male gametes derived from it.

NEET Biology Sexual Reproduction In Plants Pollination

The process by which pollen is carried from the anther to the surface of the stigma in angiosperms is called pollination.

It is of two types :

1. The pollination of one plant by pollen from another individual is called cross-pollination ;
2. On the other hand, the pollination of a carpel by the pollen from the same flower or the same individual is called self-pollination.
   • The earlier information on the concept of pollination is available in the works of Herodotus, Theophrastus, Grew, Camerarius, Kolreuter etc.
   • The concept is divided into two categories: autogamy, involving one flower, and allogamy, involving two flowers.
   • Since this classification is genetically unsound, the concept is now divided into three categories autogamy, geitonogamy and xenogamy.
     1. Utogamy. It is the transference of pollen grains from the anther of a flower to the stigma of the same flower bisexual Example Pea, Wheat, Rice, etc.
     2. Geitonogamy. When pollen from one flower is deposited on the stigma of another flower bome on the same plant.
     3. Xenogamy. Pollination takes place between two flowers made by two separate plants of the same or allied species.

The contrivances which favour autogamy are homogamy and cleistogamy. In the latter case, self-pollination is the rule.

1. Homogamy. It is the condition in which anthers and stigmas in bisexual flowers attain maturity at the same time.
2. Cleistogamy. In cleistogamy, flowers never open to expose their sex organs and the pollens fall on the stigma of the same flower Example Commelina, Viola, Oxalis, Drosera etc. Cleistogamy is followed by geocarpy in plants like groundnuts (fruits are formed in the soil).
3. Bud Pollination. Pollination occurs in bud conditions, for example, in peas and wheat. The self-pollinated flowers develop many devices like a direct touch of anthers and stigma at maturity by bending the filament of stamen on the stigma (Mirabilis jalapa) or by curving the style on the anthers having terminal porous dehiscence (Solatium ).

Sexual Reproduction In Flowering Plants NEET Notes

In Vinca rosea the anthers are present at the mouth of the corolla tube and mature when the stigma passes through the mouth of the corolla tube, causing self-pollination. In sunflower self-pollination lakes are placed by the curving of the receptive surface of the stigma downward and inward, thus coming in contact with their pollen grain. This happens when cross-pollination fails in sunflowers.

NEET Biology Sexual Reproduction In Plants Contrivances Which Favour Allogamy

They are dicliny, self-sterility, dichogamy, herkogamy and heteromorphism. The contrivance best suited to allogamy is declined. The dichotomous flowers may be protandrous or protogynous. The heteromorphic flowers may lie dimorphic or trimorphic. The polymorphism may be due to heterostyly and or heterarchy.

1. Dicliny or Unisexunlity
   • Monoecious, Example. Maize, Cucurbits, Castor
   • Dioecious. Examples, are Carica papaya, Mulberry, and Cannabis.
2. Self-sterility or incompatibility: The pollen of a flower has no fertilizing effect on die stigma of the same flower, e.g., Passiflora, Malva, Potato.
3. Dichogamy. Male and female sex organs mature at different times.
   • Protandry. Anthers mature earlier dian die gynoecium, Example, China-rose, Lady’s finger. Foeniculum, Jasmium.
   • Protogyny. Carpels mature earlier than the stamens Example, the Four o’clock plant, Custard- apple.
4. Heterostyly. Two or more types of flowers concerning the length of the style and stamen arc formed, Example, Solatium, Oxalis, Lythrum, Primula.
5. Hereogamy. Male and female sex organs are so placed in a flower that the pollen grains die and they are unable to reach the stigmas in the same flower, for example, Carnation, Gloriosa, and Calotropis.

NEET Biology Sexual Reproduction In Plants Types Of Cross-Pollination Depending Upon Agencies

1. Anemophily. Small flowers are pollinated by wind. Plants produce enormous amounts of pollen Example. Oak, Betula, grasses, rice, bamboo, Pinus (Winged Pollen grains).

• Anemophilous flowers are small and inconspicuous; never coloured or showy; do not emit any smell and nor do they secrete any nectar.
• Pollen grains are produced in large quantities which are very small, dry, smooth and light so they can be easily disseminated by wind over a wide area, helping cross-pollination.
• Stigmas are hairy and branched to licit they may entangle the pollen grains floating in the air.

2. Hydrophily: Pollination through the agency of water is called hydrophily. When pollination occurs below the water level, it is described as hypohydrogamie and when it occurs at the die level of water, it is called epiliydrogamic.

• In plants like Potamugeton, Myriophyllum etc. when? the inlloirsociKT pmlnulcs mil of witter level, wind pollimilinn occurs.
• Hydmphilv is commonly seen in the members of Ceralopliyllncene, and Najiiclaecnc. Hvdiwharitaecac, Potumogetonuceue, Aponogctonucene etc. Hypohydrogumie pollination is seen in plants like Ccralopliyllum, Najas etc.
• An interesting pollination mechanism is seen in plants like Ruppia Maritime and Vallisncria spiralis. In Ruppia the flowers; are bisexual and protandrous. The anthers release pollen into the water and the grains float on the water’s surface.
• Now the peduncle and pedicel elongate till the stigma reaches the water surface and comes in contact with the floating grains. After pollination, the stalk contracts and the fruit matures under water. In Vallisncria, which is a rooted submerged aquatic plant, the male flowers are born in a spadix and the females are solitary.
• The male flowers are set free below water level but they open on the surface where they float. The pedicel of the female flower elongates till it reaches the water surface where it comes in contact with the pollen grains.

3. Zoophily. Pollination by the agency of animals.

1. Chiropterophily. Pollination by bats, Example, Anthocephcilus, Bauhinia, Kigelia pinnata, Adensonia (Boabab tree)
2. Ornithophily. Pollination by birds, for example, Bignonia, Erythrina indica, Bombax, Agave, and Grevillea.
3. Malacophily. Pollination by slugs and snails, Example, Arisaema. and other aroids.
4. Entomophily. Pollination by insects, for example, Jasmine, Rosa, and Magnolia.

Sexual Reproduction In Flowering Plants NEET Study Material

These flowers possess the following characteristic features :

• The insect-pollinated flowers are fragrant and omit scent and odour, for Example, Cestrum, Jasmine etc. Rafflesia gives out obnoxious and repelling odours.
• The insect-pollinated flowers are beautifully coloured. In flowers, most petals are brightly coloured.
• Sometimes, when flowers themselves are not conspicuous, other parts may become coloured and showy to attract the insects Example bracts in Bougainvillea, leaves in Euphorbia pulcherrima, one sepal in Mussaenda etc.
• The nectariferous glands produce nectar for feeding the visiting insects.
• Nectariferous glands are present at such positions on floral parts to encounter the anthers and stigmas.
• In Viola (pansy), markings on petals (nectar guides) are present which guide the insects to nectaries.
• In entomophilous plants, the pollen grains become sticky or spiny so that they may easily get attached to the bodies of visiting insects.
• To catch the pollen grains, the stigmas become sticky.
• Flowers become more conspicuous by grouping Example capitulum, corymb etc.
• In plants like Papaver, Rosa, Clematis etc. edible pollen grains are produced.
• Some of die pollen grains stick to the body of insects while feeding on the edible pollen grains.
• In orchid Ophrys, the shape and colour of the petals are like a female wasp. Male wasp mistakes the flowers of Ophrys for female wasp and tries to copulate, thus pollinating the flowers.
• In Yucca, Yucca-moth bores a hole in the ovary of the Yucca flower and lays its eggs in it. Then it collects pollen from several flowers and pushes the whole of the pollen down the hollow end of the stigma.
• Fertilization takes. place and seeds develop. Larvae feed on developing seeds.
• Some seeds remain unconsumed to propagate the species. Moth cannot survive without Yucca flowers and Yucca fails to reproduce sexually without moth.

NEET Biology Sexual Reproduction In Plants Development And Formation Of Male Gametes

Development of male gametophyte starts in pollen grains, while still present in the microsporangium or pollen sac (precocious germination). Microspore undergoes only two mitotic divisions.

• First mitotic division leads to the formation of a vegetative cell and a generative cell.
• The vegetative cell is also called the tube cell. These cells do not possess any cell wall and, hence are represented only by cell membranes. A temporary callose wall is laid down between the two cells (Groska-Bry-Lass, 1967).
• The callose wall spreads between the generative cells and the intestine to finally pinch it off.
• Soon, this callose wall dissolves and the generative cell lies freely in the cytoplasm of the vegetative cell. Generative cells may be elliptical, lenticular or even spindle-shaped.
• The cytoplasm contents of the generative cells are almost hyaline and do not possess much-stored food material. The large vegetative cell contains fat.
• starch and some type of protein granules. It is usually at this two-celled stage that pollen grains are liberated from pollen sacs of anther lobes.
• Rarely generative cells may further divide to form two male gametes. All these stages for the development of male gametophytes are grouped under pre-pollination stages.
• After the falling of pollen grains on the stigma, post-pollination changes occur.
• Pollen grain absorbs water and nutrients of the stigmatic secretion through its germ pores. The intine protrudes out through one of the germ pores or a germ furrow.
• The generative nucleus divides to form two male nuclei, which become surrounded by cytoplasmic masses and appear as distinct male gametes. Protruded intine forms pollen tube. The tube nucleus migrates to the pollen tube. The formation of male gametes can occur in vegetative cells or pollen tubes.
• Usually, generative cell comes down into pollen tubes and then divide to form the male gametes. The hindered region of the pollen tube is highly vacuolated. This region is plugged from the anterior part by the development of callose. The male gametophyte in angiosperms is highly reduced.
• Usually, there is a single pollen tube and pollen grains are termed monosphonous. In Malva, Althea and other members of the family Malvaceae and Cucurbitaceae, the condition is polysiphonous with as many as 14 pollen tubes.

NEET Biology Sexual Reproduction In Plants Megasporogenesis And Development Of The Female Gametophyte

The ovule develops as a small outgrowth from the tissue of the placenta, A single hypodermal cell in the nucellus starts functioning as an archesporium which, is also called a primary archesporial cell. This cell divides by a periclinal wall to form a primary parietal and sporogenous cell.

• The primary parietal cell undergoes repeated divisions forming a parietal tissue. The primary sporogenous cell functions directly as the megaspore mother cell which divides twice the first division being mciotic and the second mitotic, forming four haploid cells arranged in a row.
• Three of the upper cells degenerate and the remaining lowermost cell forms die functional megaspore. In the meantime, two integuments are disclosed from the base of the ovule, which envelops the mature ovule. ‘1 The megaspore represents the first cell of the female gametophyte.
• The megaspore nucleus divides thrice to give rise to eight nuclei. Four of the nuclei migrate to one pole and the remaining four die opposite jxilc; one nucleus from the cadi of the pole comes to lie in the centre of die embryo sac where the two lose together to form a secondary nucleus.
• The three nuclei at the base form the antipodal tells and the three nuclei at the apex organise into an egg apparatus, consisting of two synergies and an egg between them.
• The ovule is a rounded structure attached to the placenta by a stalk, die funicle, The place of attachment of the funicle to the body of the ovule is called a Lilium. Hie basal region of the ovule, where integuments arise, is termed a thalaza. ‘The lire ovule consists of integuments mid nucellus.

1. Orthotropous or atropous straight. ovule is erect. Funcile, and chalaza micropyle lie on the same verticle line e.g polygonum, Rumex
2. Anatropous or Inverted or resupinate. Ovule bends along the funnel. Micropyle lies close to the hilum. Micropyle and chalaza lie on the same vertical line Example Solanum, Anemone, Helianthus.
3. Amphitropous or Transverse. The ovule is placed transversely or at a right angle to its stalk, for Example, Lenina and some crucifers.
4. Campylotropous or Curved. Chalaza and micropyle do not lie in a straight line, for example, Capparis, Mustard, Pisum, and family Chenopodiaceae.
5. Circinotropous. This ovule is inverted at an angle of 360° so that the ovule again fir becomes orthotropous and coiled around by funiculus Example opuntia.
6. Hemianatropous. It is intermediate between ortho and anatropous types of ovules, for example, members of Primulaceae, Ranunculaceae and some crucifers.

Sexual Reproduction In Flowering Plants NEET Study Material

NEET Biology Sexual Reproduction In Plants Fertilization

The process of nuclear fusion between the male nucleus and an egg nucleus is referred to as fertilization. It produces a diploid zygote. The second male gamete amalgamates with the secondary nucleus. Double fertilization is a common occurrence.

• The pollen tube infiltrates the embryo sac. The pollen tube enters the embryo sac from many locations.
• These represent Porogamy: the ingress of the pollen tube through the micropyle.
• Illustration Lily chalazogamy refers to the introduction of the pollen tube through the chalazal end, exemplified by Juglans (walnut) and Casuarina. Mesogamy refers to the passage of the pollen tube through the funiculus or integuments. Example: Cucurbita, Populus.
• The apex of the pollen tube ruptures within the embryo sac, discharging both male gametes. One gamete penetrates the egg and amalgamates with its nucleus to create an oospore or zygote.
• The amalgamation of the male gamete with the ovum nucleus is referred to as fertilization.
• In angiosperms, the 8-nucleate Polygonum-type embryo sac comprises two polar nuclei centrally located. The polar nuclei amalgamate to create a diploid secondary nucleus (2N).
• The 2nd male gamete (N) of the pollen grain fuses with this secondary nucleus (2N) to form triploid endosperm (3N). This technique is referred to as twofold fertilization.

Endosperm

Endosperm is usually triploid and is formed as a result of triple fusion after fertilization. The endosperm provides food to the young embryo.

Three different types of endosperms have been reported in angiosperms

1. Nuclear endosperm
2. Cellular endosperm
3. Global endosperm.

Development of endosperm. Endosperm develops after double fertilization in angiosperms. It is triploid and develops from the primary endosperm nucleus.

It is meant to nourish the embryo. As the endosperm develops fully in the fertilized ovules, it may show the effect of genes present in the male gamete.

It is called Xenia. Endosperm development is accompanied by degeneration of the nucellus. Some food is also obtained from plants as well as the endothelium.

Types Of Endosperm

1. Nuclear endosperm. In nuclear endosperm development, the nucleus divides by free nuclear division, there is the appearance of the central vacuole, all the nuclei are pushed towards the periphery then starts cytokinesis and results in the formation of cells as in Capsella bursapastoics, but in coconut vacuole persists which is filled with fluid.
2. Cellular endosperm. In cellular endosperm every division is followed by cytokinesis, so endosperm is cellular from the very beginning Example Datura, Petunia.
3. Helobial endosperm. It is intermediate between cellular and nuclear endosperm. The first division is followed by. cytokinesis to form two unequal cells, a micropylar cell and a chalazal cell. Further divisions in each cell are free nuclear divisions. This type of endosperm is found in the order Helobiales.

The endosperm may persist in the seed or be consumed by the developing embryo. In the latter case, the food is generally stored in cotyledons. Ruminate or convoluted endosperm occurs in Areca (Betel nut) and Passiflora. The hard endosperm is found in Date, vegetable Ivory and Areca.

Embryo Development

The embryogeny (Crucifer /Onagrad type). The zygote or oospore divides by a transverse wall into an upper suspensor cell and a lower embryonal cell. The suspensor cell which lies towards the micropylar end, divides by transverse divisions to constitute 7-10 cells called suspensor.

• The upper cell of the suspensor filament towards the micropylar end is called the historical cell, whereas the cell lying above the embryo cell is called hypophysis.
• The haustorial cell enlarges in size and attaches the suspensor to the tip of the embryo sac. The embryonal cell divides by a second longitudinal division at a right angle to the first and then by transverse division to form an octant or eight-celled embryo.
• Out of these eight cells, the lower four cells of octant away from the die suspensor give rise to the plumule and the two cotyledons, while dying above four cells of octant near the suspensor from the hypocotyl and stele of the radicle.
• Now this octant divides by a periclinal division to form an outer single-layered dermatogen from which arises the epidermis layer. The inner cells further divide to form periblem below’ die dermatogen and die central plerome. The periblem forms the cortex while the plerome gives the stele of the embryo.
• The lowermost cell of the suspensor, which lies just above die octant cells, is known as hypophysis. The hypophysis divides to give rise to the dermatogen and periblem of the radicle. A fully developed embryo of dicotyledons has an embryonal axis differentiated into a plumule, two cotyledons and a radicle.
• In die beginning embryo is globular. When two cotyledons differentiate from the sides with faint plumule in the centre, the embryo becomes heart-shaped. Now the embryo undergoes rest and the ovule is transformed into a seed.

Sexual Reproduction In Flowering Plants NEET Study Material

Monocot Embryogeny (Sagittaria Type)

The zygote or oospore divides transversely, producing a vesicular suspensor cell towards the micropylar end and an embryonal cell towards the chalazal end. The embryo cell divides transversely again into a terminal and a middle cell. The terminal cell divides vertically and transversely into a globular embryo. It forms a massive cotyledon and a plumule.

• The growth of cotyledon pushes the plumule to one side. Remains of second cotyledon occur in some grasses. It is called epiblast. The single cotyledon of monocots is called scutellum. It is shield-shaped and appears terminal.
• The middle cell gives rise to hypocotyl and radicle. It may add a few cells to the suspensor. Both radicle and plumule develop covering sheaths called coleorhiza and coleoptile respectively. They appear to be extensions of the scutellum.

Polyembryony

It is defined as the development of two or more embryos within an ovule. It was discovered by Leeuwenhoek in 1719 in orange. In angiosperms, the multiple embryos are produced in the following ways.

1. By fertilization of synergids or antipodal cells by sperms introduced in the pollen sac by additional pollen tubes, Example, Plantago, Poa, Allium
2. By cleavage of the single zygote or a young embryo into 2 or more parts, each of which develops into an embryo, For Example, members of Orchidaceae
3. One or more cells of the nucellus or integuments develop into embryos which soon project into the embryo sac and are nourished by the endosperm, For Example, Citrus, Mangifera, Eugenia
4. The occurrence of more than one embryo sacs which usually develop from the
   derivatives of a single or more than one megaspore mother cell, for example, Brassica,

• The flowers of Asteraccac ami Labiatae families are generally pollinated by bees and butterflies.
• The two cells are unequal. A large one is called a tube cell or vegetative cell and the small one is called a generative cell.
• This division occurs when microspores are still inside the pollen sac.
• Microspores are shed at this 2-celled stage. Later, the development of male gametophyte occurs after pollination.] The pollination by birds is common in coral trees, bottle brushes, Iiulca monospen and silk cotton trees.
• Hie pollination by bats is carried out in Adansonia and Kigelia. The wind-pollinated flowers are generally unisexual, as in coconut palm, dale palm, maize, and many grasses. Cannabis. Hydrophilv is common in water plants especially submerged ones, like Vallisneria, Ceratophyllum, Zostera

Differences between self-pollination and cross-pollination.

NEET Biology Sexual Reproduction In Plants Quanta To Memory

• Entomophily. In angiosperms, entomophily occurs in about 80% of the flowers. Pollen kit is characteristic of entomophilous pollen.
• Most of the entomophilous flowers are pollinated by members of Hymenoptera, Lepidoptera, Diptera and Coleoptera and only a few by other groups.
• An interesting pollination mechanism is seen in many plants. While Centaurea shows a piston mechanism for pollination, Salvia exhibits a lever mechanism.
• Pollination by water is called hydrophily. Pollination may occur below the water level (hypohydrogamic) or at the level of water (epihydrogamic).
• Translator Mechanism. In Calotropis and related plants, pollen grains are aggregated to form translators, each having two pollinia attached by a corpusculum. The translator is picked up and transferred by an insect visiting flowers for nectar”.
• Erythrina. It is pollinated by crows as well as squirrels.
• Adansonia. A flower bears 1500—2000 stamens.
• The effect of pollen grain on the characters of endosperm is called xenia.
• Sometimes pollen grains are present in a sac-like mass known as pollinium, for Example, Calotropis and Orchids etc.
• In some plants Example, Malva, and Althaea, 10-14 pollen tubes develop from the same pollen grain, but only one becomes functional.

Sexual Reproduction In Flowering Plants NEET Mcqs

NEET Biology Sexual Reproduction In Plants Questions From Competitive Examinations

Question 1. In the Kigcllia prenatal /Sausage tree, pollination is performed by :

1. Bats
2. Birds
3. Insects
4. Wind.

Answer: 1. Bats

Question 2. Apple growers usually keep bees in the orchard even though apples are usually wind-pollinated because :

1. Wind pollination results in apples of inferior quality
2. Insect pollination results in apples of superior quality
3. Wind pollination may fail at the right time and bees would bring about pollination in such a situation
4. Bees can inject honey into the apples and make them sweeter.

Answer: 3. Wind pollination may fail at the right time and bees would bring about pollination in such a situation

Question 3. Self-pollination means :

1. Occurrence of male and female sex organs in the same flower
2. Germination of pollen within the same anther
3. Transference of pollens from anther to stigma within the same flower
4. Transference of pollen from one plant to the stigma of a neighbouring plant.

Answer: 3. Transference of pollens from anther to stigma within the same flower

Question 4. Stigma is always rough and sticky in :

1. Entomophilous flowers
2. Anemophilous flowers
3. Hydrophilous flowers
4. All types of flowers.

Answer: 1. Entomophilous flowers

Question 5. Progeny resulting from cross-pollination :

1. Show greater genetic variability and are evolution- nary important
2. Homozygous and show phenotypic uniformity
3. Arc always sterile
4. Always show recessive characters.

Answer:  1. Show greater genetic variability and are evolution- nary important

Question 6. Maturation of stamens and pistils at different times in the same flower is called :

1. Dichotomy
2. Dichogamy
3. Heterospory
4. Heterostyly.

Answer: 2. Dichogamy

Question 7. Pollination by ants is :

1. Malacophily
2. Myrmccophily
3. Omithophily
4. Entomophily.

Answer: 2. Myrmccophily

Question 8. Some flowers possess pleasant odour and attractive colours for:

1. Hydrophily
2. Anemophily
3. Entomophily
4. All of the above.

Answer: 3. Entomophily

Question 9. Anemophily means :

1. Pollination by wind
2. Pollination by birds
3. Pollination by animals
4. Animal-loving plants.

Answer: 1. Pollination by wind

Sexual Reproduction In Flowering Plants NEET Mcqs

Question 10. Wind pollination is common in :

1. Legumes
2. Lilies
3. Grasses
4. Orchids.

Answer: 3. Grasses

Question 11. In which one of the following pollination is autogamous?

1. Geitonogamy
2. Xenogamy
3. Chasmogamy
4. Cleistogamy.

Answer: 4. Cleistogamy.

Question 12. Embryo sac is :

1. Microgametophyte.
2. Microsporangium
3. Megagametophyte
4. Megasporangium.

Answer: 3. Megagametophyte

Question 13. The 8-nucleate embryo sac is :

1. Monosporic
2. Bisporic
3. Tetrasporic
4. All the above.

Answer: 4. All the above.

Question 14. A mature male gametophyte is formed from pollen mother cell by :

1. One meiotic division
2. Two meiotic divisions
3. One meiotic and two mitotic divisions
4. Three meiotic divisions.

Answer: 1. One meiotic division

Question 15. Passage of pollen tube through micropyle while reaching the embryosac is :

1. Monogamy
2. Porogamy
3. Dicliny
4. Dichogamy.

Answer: 2. Porogamy

Question 16. The polygonum type of embryo sac is:

1. 8-nucleate
2. 16-nucleate
3. 24-nucleate
4. 32-Nucl

Answer: 1. 8-nucleate

Question 17. Tapetum occurs in:

1. 8-nucleate
2. Ovary Wall
3. Male gametophyte
4. Female gametophyte

Answer: 1. 8-nucleate

Sexual Reproduction In Flowering Plants NEET Mcqs

Question 18. Which one is produced as a result of double fertilization?

1. Seed
2. Fruit
3. Megaspore
4. Endosperm

Answer: 4. Endosperm

Question 19. A component of the female reproductive system is:

1. Stamens
2. Anther
3. Microscope
4. Embryo

Answer: 4. Embryo

Question 20. Mango and Guava ate propagated through.lt :

1. Tissue culture
2. Grafting
3. Stem cuttings
4. Layering.

Answer: 2. Grafting

Question 21. In a grafted plant, slock has 48 chromosomes while scion has 2d chromosomes. Idle chromosome numbers for root cells and eggs are :

1. 48and 24
2. 24and 24
3. 24and 12
4. 48 and 12.

Answer: 4. 48 and 12.

Question 22. Pollen grains are non-green due to :

1. Absence of plastids
2. Degeneration of plastids
3. Conversion of plastids into chromoplasts
4. Attraction of vectors.

Answer: 3. Conversion of plastids into chromoplasts

Question 23. The pollen grain of a tetraploid plant brings about fertilization in a diploid plant. The endosperm of the seed will be :

1. 2
2. 3
3. 4
4. 5

Answer: 3.  4

Question 24. Multinucleate condition is present in :

1. Quiescent centre
2. Maize
3. Meristematic tissue
4. Liquid endosperm of Coconut.

Answer:  4. Liquid endosperm of Coconut.

Question 25. If meiosis occurs inside pollen grain and egg nuclei, it will be :

1. Zygotic ineiosis
2. Gametic meiosis
3. Sporic meiosis
4. None of the above.

Answer: 2. Gametic meiosis

Sexual Reproduction In Flowering Plants NEET Exam Preparation

Question 26. Formation of the embryo from vegetative cells derived from the zygote is called :

1. Apoinixis
2. Adventive polyembryony
3. Apospory
4. Diploid polyembryony.

Answer: 2. Adventive polyembryony

Question 27. The formation of an organiser from a single, male gamete without fusion with an egg is an example of:

1. Parthenogenesis
2. Apogamy
3. Apospory
4. Parthenocarpy.

Answer: 1. Parthenogenesis

Question 28. Adventive embryonic in Citrus is due to :

1. Nucellus
2. Integuments
3. Zygotic embryo
4. Fertilized egg.

Answer: 1. Nucellus

Question 29. In grasses what happens in the microspore mother cell for the formation of mature pollen grains :

1. One meiotic and two mitotic divisions
2. One meiotic and one mitotic divisions
3. One meiotic division
4. One mitotic division.

Answer: 2. One meiotic and one mitotic division

Question 30. Which of the following statements is wrong :

1. Naked seeds are seen in gymnosperms
2. Pteridophyta produces endosperm
3. Basidiocarpous fruiting body of fungs
4. Capsule is the sporophyte

Answer: 2. Pteridophyta produces endosperm

Question 31. Double fertilization was given by :

1. Nawaschin
2. Maxwell
3. Einstein
4. Antony Hewert

Answer: 1. Nawaschin

Question 32. Hydroponics is :

1. Plant growth in mineral-deficient soil
2. Soil conservation
3. Plant growth under laboratory conditions
4. Plant growth in liquid culture medium.

Answer: 4. Plant growth in liquid culture medium.

Sexual Reproduction In Flowering Plants NEET Exam Preparation

Question 33. Number of nuclei present in common embryo sac tire :

1. Six
2. Eight
3. Twelve
4. Twenty-four.

Answer: 2. Eight

Question 34. Perisperm is :

1. Remains of nucellus
2. The outer part of the embryo sac
3. Degenerated synergid
4. Degenerated secondary nucleus

Answer: 1. Remains of nucellus

Question 35. In a flowering plant, archesporium gives rise to :

1. Only tapetum and sporogenous cells
2. Only the wall of the sporangium
3. Both the wall and the sporogenous cells
4. Wall and the tapetum.

Answer: 3. Both the wall and the sporogenous cells

Question 36. Pollen grains can tolerate extremes of temperature and desiccation because their exine consists of:

1. Cutin
2. Suberin
3. Sporopollenin
4. Close

Answer: 3. Sporopollenin

Question 37. The plant part has two generations, one within the other:

1. Seed
2. Germinated pollen grain
3. Embryo
4. Unfertilized ovule

Answer: 1. Seed

Question 38. Pollen tube usually enters the embryo sac :

1. Between one synergid and central cell
2. By knocking off antipodal cell
3. Through one of the synergids
4. Directly penetrate the egg.

Answer: 1. Between one synergid and central cell

Question 39. A plant root has 16 cells thus :

1. Gamete has 16 cells
2. Gamete has 8 cells
3. Endosperm has 16 cells
4. The endosperm has 8 cells.

Answer: 1. Gamete has 16 cells

Question 40. Which one of the following statements is correct?

1. Sporogenous tissue is haploid
2. Endothecium produces the microspores
3. Tapetum nourishes the developing pollen
4. The hard outer layer of pollen is called intine.

Answer: 3. Tapetum nourishes the developing pollen

Question 41. A diploid female plant is crossed with the tetraploid male. The ploidy of endosperm will be :

1. Tetraploidy
2. Diploidy
3. Triploidy
4. Pentaploidy.

Answer: 1. Tetraploidy

Question 42. Which of the following represents the edible part of the fruit of Litchi?

1. Pericarp
2. Mesocarp
3. Juicy aril
4. Endocarp.

Answer: 3. Juicy aril

Sexual Reproduction In Flowering Plants NEET Exam Preparation

Question 43. Through which cell of the embryo sac. does the pollen tube enter the embryo sac?

1. Egg cell
2. Central cell
3. Persistant synergid
4. Degenerated synergid

Answer: 4. Degenerated synergid

Question 44. Which one of the following mg represents an ovule, where the embryo sac becomes horse-shoe shaped and the funiculus and micropyle are close to each other?

1. uvinotiopous
2. Anatropous
3. Amphitropous
4. Atropous.

Answer: 3. Amphitropous

Question 45. Which is vivipary an undesirable character for annual crop plants?

1. It reduces the vigour of the plant.
2. The seeds cannot be stored under normal conditions for die next season.
3. The seeds exhibit long dormancy
4. It adversely affects the fertility of the plant.

Answer: 2. The seeds cannot be stored under normal conditions for die next season.

Question 46. In which one pair both dead plants can be vegetatively propagated by leal pieces?

1. Bryophyllum and Kalanchoe
2. Chrysandiemum and Agave
3. Agave and Kalanchoe
4. Asparagus and Bryophyllum.

Answer: 1. Bryophyllum and Kalanchoe

Question 47. In a type of apomixis known as adventive embryonic, embryos develop directly from the :

1. Nucellus or integuments
2. Synergids or antipodals in an embryo sac
3. Accessory embryo sacs in the ovule
4. zygote.

Answer: 1. Nucellus or integuments

Question 48. Double fertilization involves :

1. Fertilization of the egg by two male gametes
2. Fertilization of two eggs in the same embryo sac by two sperms
   brought by one pollen tube.
3. Fertilization of the egg and the central cell by two sperms brought
   by different pollen tubes.
4. Fertilization of the egg and central cell by two sperms brought by the same pollen.

Answer: 4. Fertilization of the egg and central cell by two sperms brought by the same pollen.

Question 49. In some plants anthers and sdgma grow and mature at the same time. This phenomenon is called

1. Homogamy
2. Syngamy
3. Allogamy
4. Fusion.

Answer: 1. Homogamy

Question 50. For the formation of a tetraspores embryo sac, how many megaspores mother cells are required?

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

Answer: 2. 2

Sexual Reproduction In Flowering Plants NEET Previous Year Questions

Question 51. The pollen sac in Cycas is called :

1. Megasporophyll
2. Megasporangium
3. Microsporophyl
4. Microsporangium.

Answer: 4. Microsporangium.

Question 52. Polygonum type of embryo sac is :

1. 8-nucleate and 7-celled
2. 8-nucleate and 8-celled
3. 8-nucleic and 8-called
4. 7-nuclcnlc ami 8 celled.

Answer: 1. 8-nucleate and 7-celled

Question 51. In die angiosperm ovule central cell of the embryo sac, before the entry of the pollen tube, contains;

1. A single haploid nucleus
2. One diploid and one haploid nuclei
3. Two Imploid polar nuclei
4. One diploid secondary nucleus

Answer: 4. One diploid secondary nucleus

Question 54. Xenia refer to :

1. Effect of pollen on stem
2. Effect of pollen on the taste of fruit
3. Effect of pollen on vascular tissue
4. Effect of pollen on endosperm.

Answer: 4. Effect of pollen on endosperm.

Question 55. Pollination by snails and slugs is known as :

1. Entomophilous
2. Omithophilous
3. Anemophilous
4. Malacophilous

Answer: 4. Malacophilous

Question 56. The arrangement of the nuclei in a normal embryo sac in the dicot plants is :

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

Answer: 2.  3 + 2 + 3

Question 57. Which one of the following is surrounded by a callose wall?

1. Male gamete
2. Egg
3. Pollen grain
4. Microspore mother cell.

Answer: 2. Pollen grain

Question 58. Male gametes in angiosperms are formed by the division of:

Generative cell

Vegetative cell

Microspore mother cell

Microspore

Answer: 1. Generative cell

Question 59. Eight nucleate embryo sacs are :

1. Always diasporic
2. Always tetraspores
3. Always monosporic
4. Sometimes monosporic, sometimes diasporic and sometimes tetraspores.

Answer: 4. Sometimes monosporic, sometimes diasporic and sometimes tetraspores.

Question 60. Double fertilization (or triple fusion) leading to initiation of endosperm in angiosperms, requires :

1. Fusion of 4 or more polar nuclei and the second male gamete only
2. Fusion of 2 polar nuclei and second male gamete only
3. Fusion of one polar nucleus and second male gamete only
4. All the above types of fusions in different types of angiosperms.

Answer: 2. Fusion of 2 polar nuclei and second male gamete only

Question 61. Many scientists consider viruses as living entities because these:

1. Respire
2. Can cause diseases
3. Reproduce (inside host)
4. Respond to tough environment.

Answer: 3. Reproduce (inside host)

Question 62. The mode of asexual reproduction in Hamlet and.

1. Formation of gametes
2. Endospore formation
3. Conjugation
4. Zoospore formation

Answer: 2. Endospore formation

Sexual Reproduction In Flowering Plants NEET Previous Year Questions

Question 63. Through which cell of the embryo sac. Does the pollen tube enter the embryo sac?

1. Egg cell
2. Central cell
3. Persistent synergid
4. Degenerated synergid

Answer: 4.Degenerated synergid

Question 64. Which one of the following represents an ovule, where the embryo w becomes horse-shoe shaped and funiculus and mu-ropy lc are close to each other?

1. Circinotropous
2. Antropous
3. Amphitropous
4. Atropous

Answer: 3. Amphitropous

Question 65. Which of the following represents the edible part of the fruit of litchi?

1. Pericarp
2. Mesocarp
3. Juicy aril
4. Endocarp.

Answer: 3. Juicy aril

Question 66. The study of pollen grain is called :

1. Etymology
2. Palynology
3. Paleobotany
4. M-taxonomy.

Answer: 2. Palynology

Question 67. Select the correct order of endosperm types :

1. Cellular, global, free nuclear
2. Cellular, free nuclear, global
3. Helobial, free nuclear, cellular
4. Free nuclear, cellular, and global
5. Free nuclear, global, and cellular.

Answer: 3. Free nuclear, cellular, and global

Question 68. Endosperm is consumed by developing embryo in the seed of:

1. Pea
2. Maize
3. Coconut
4. Castor.

Answer: 1. Pea

Question 69. Nucellar polyembryony is reported in species of:

1. Citrus
2. Gossypium
3. Triticum
4. Brassica.

Answer: 1. Citrus

Question 70. Filiform apparatus is a characteristic feature of:

1. Suspensor
2. Egg
3. Synergid
4. Zygote.

Answer: 3. Synergid

Question 71. What would be the number of chromosomes of the aleurone cells of a
plant with 42 chromosomes in its root lip cells?

1. 42
2. 63
3. 84
4. 21.

Answer: 2.63

Question 72. I lie genomic consists of many free pistils in the lower of

1. Tomato
2. Papaver
3. Michelia
4. Aloe

Answer: 3. Michelia

Question 73. Both autogamy and geitonogamy are prevented by:

1. Cucumber
2. Castor
3. Maize
4. Papaya.

Answer: 4. Papaya.

Question 74. An organic substance that can withstand environmental extremes eminently he pleaded that any enzyme is :

1. Spoiopollenin
2. Lignin
3. Cellulose
4. Cuticle.

Answer: 1. Spoiopollenin

Question 75. Plnccntnlion in tomato and lemon is :

1. Free central
2. Marginal
3. Axile
4. Parietal.

Answer: 3. Axile

Question 76. Which of these is a condition that makes flowers invariably
autogamous?

1. Dioccy
2. Self-incompatibility
3. Cleistogamy
4. Xenogamy
5. Syngamy.

Answer: 3. Cleistogamy

Question 77. Math the items in column I with those in column II and choose the correct answer.

1. 1- B; 2- C; 3- E; 4 – D; 5 -A
2. 1-A; 2 – C; 3 – B; 4 – D: 5 – E
3. 1 – B; 2 – C; 3 – A; 4 – D; 5 – E
4. 1 – B; 2 – D; 3 – E; 4 – A; 5 – C
5. 1 – C; 2 – D; 3 – E; 4 – A; 5 – B

Answer:  1. 1- B; 2- C; 3- E; 4 – D; 5 -A

Question 78. Megasporangium is equivalent to :

1. Fruit
2. Nucellus
3. Ovule
4. Embryo sac

Answer: 3. Ovule

Question 79. The advantage of cleistogamy is :

1. More vigorous offspring
2. No dependence on pollinators
3. Vivipary
4. Higher genetic variability

Answer:  2. No dependence on pollinators

Question 80. Perisperm differs from endosperm in :

1. Having no reserve food
2. Being a diploid tissue
3. Its formation by the fusion of a secondary nucleus with several sperms
4. Being a haploid tissue

Answer:  2.  Being a diploid tissue

NEET Biology Reproduction In Angiosperms Multiple Choice Questions

Question 1. Uniscxunlity of flowers prevents:

1. Autogany and geitonogamy
2. Both geitonogamy and xenogamy
3. Autogamy but not geitonogamy
4. geitonogamybut not xenogamy

Answer: 3. Autogamy but not geitonogamy

Question 2. The endosperm is completely consumed by the developing embryo in :

1. Pea and castor
2. Maize and castor
3. Castor and groundnut
4. Maize and Pea

Answer: 1. Pea and castor

Question 3. A plant part having two generations is :

1. Embryogeny
2. Unfertilized ovule
3. Germinated pollen
4. Seed, grain

Answer: 4. Seed, grain

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 4. The end products of sexual reproduction are :

1. Fruits
2. Flowers
3. Inflorescence
4. Fruits and seeds

Answer: 4. Fuits and seeds

Question 5. Differentiation and development of floral primordium is preceded by :

1. Hormonal changes
2. Structural change
3. Formation of gynoecium
4. Both structural and hormonal changes.

Answer: 4. both structural and hormonal changes.

Important MCQs on Reproduction in Flowering Plants Question 6. Which of the following is a mismatch?

1. Long and slender stalk – Filament
2. Long and bilobed – Anther
3. Short and bilobed – Anther
4. Microsporangia – Anther.

Answer: 2. Long and bilobed – Anther

Question7. Microsporangium develops and :

1. Form pollen
2. Become pollen sac
3. Produce tapetum
4. Lead to the formation of embryo sac.

Answer: 1.  Form pollen

Question 8. In the young anther, a group of homogenous compactly arranged sporogenous tissue occupies the centre of the microsporangium. It undergoes :

1. Meiotic division to form microspore tetrad
2. Growth forms pollen sac
3. Mitosis to form tetrad
4. Meiosis to form pollen sac.

Answer: 1. Meiotic division to form microspore tetrad

Question 9. Pollen grains are spherical and measure about:

1. 10-12 diameters
2. 25-50 in diameter
3. 50-70 in diameter
4. Less than 10 mm in diameter.

Answer:2. 25-50 in diameter

Question 10. In 40 per cent of angiosperm pollen grains are arrested at:

1. 2-celled stage
2. 3-celled stage
3. One vegetative and generative cell
4. Two generative and one vegetative cell

Answer: 2. 3-celled stage

Question 11. Pick out the mismatch :

1. Embryosac – Female gametophyte
2. Functional megaspore – 2 celled
3. Typical embryo sac at maturity – 8 nucleate, 7 celled
4. Egg apparatus – 3 celled

Answer: 2. Functional megaspore – 2-celled

Important MCQs on Reproduction in Flowering Plants Question 12. Which of the following is/are biotic pollinators of plant species?

1. Bees, butterflies, beetles
2. Sunbird, hummingbird
3. Gecko, lemur, Rodents
4. All of the above.

Answer: 4. All of the above.

Question 13. Continued self-pollination leads to inbreeding depression. Which of the following devices encourage cross-pollination?

1. Pollen released before stigma becomes receptive
2. Stigma becomes receptive before pollen release
3. Different positions of anther and stigma
4. All of the above.

Answer: 4. All of the above.

Question 14. In plants which shed pollen at the 3-celled stage, pollen tube. carry :

1. One male gamete from the beginning’
2. One male gamete
3. One vegetative and One generative cell
4. Two vegetative and one generative cells.

Answer: 1. wo male gametes from the beginning’

Question 15. Callose covering is present over :

1. Egg
2. Pollen grain
3. Male gamete
4. Microspore mother cells.

Answer: 4. Microspore mother cells.

Question 16. The arrangement of nuclei in a normal dicot embryo sac is :

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

Answer: 2.  3 + 2 + 3

Question 17. The function of the tapetum is

1. Protective
2. Nutritive
3. Respiratory
4. All of above

Answer: 2. Nutritive

Question 18. A typical dicot embryo consists of:

1. Epicotyl and plumage
2. Hypocotyl and radicle
3. Embryonal axis and two cotyledons,
4. Embryonal axis and scutellum.

Answer: 3. Embryonal axis and two cotyledons,

Important MCQs on Reproduction in Flowering Plants Question 19. The wall of The fruit may be flashy in :

1. Guava
2. Orange
3. Mango
4. All of the above.

Answer: 4. All of the above.

Question 19. Which of the following fruits contains thousands of seeds?

1. orchid fruit
2. Ficus
3. Orobanchae and striga
4. 1 and 3.

Answer: 4. 1 and 3.

Question 20. Which of the following is the correct labelling for the figure given below :

1. p/Thalamus Q/ovary R/style s/stigma
2. Stigma-style ovary stigma
3. Thalamus-style ovary stigma
4. Thalamus Ovary stigma style.

Answer: 4. Thalamus Ovary stigma style.

Question 21. Select the mismatched pair.

1. Microsporangium
2. Megasporangium
3. Pollen grain
4. Embryo sac

Answer: 1 . Microsporangium

Question 22. The given diagram shows the microsporangium of a mature anther. Identify P, Q and R.

1. P – Middle layer, O – Endothecium, R – Tapetum
2. P – Endothecium, O – Tapetum, R – Middle layer
3. P – Endothecium, O – Middle layer, R – Tapetum
4. P – Tapetum, B – Middle layer, R – Endothecium.

Answer:  3.  P – Endothecium, O – Middle layer, R – Tapetum

Sexual Reproduction In Flowering Plants MCQ For NEET Question 23. Refer to the given statements.

1. The outer exine is made up of sporopollenin.
2. The inner inline is pecto-cellulosic.
3. Generative cells are bigger and contain abundant food reserves.
4. The vegetative cell is small and floats in the cytoplasm of the generative cell

Answer: 3. Generative cells are bigger and contain abundant food reserves.

Question 24. Which of the given statements are not true regarding the structure of pollen grain

1. (1) and (2)
2. (2) and (3)
3. (3) and (4)
4. (1) and (4).

Answer: 3. (3) and (4)

Question 25. Study the following statements regarding the structure of microsporangium and select the correct answer.

(i)Microsporangium is generally surrounded by four wall layers – epidermis, endothecium, middle layers and tapetum

(ii) The outer three layers perform functions of protection and dehiscence of anthers.

(iii)Cells of tapetum undergo meiosis and produce microspore tetrads.

1. Only (1) and (2) are true.
2. Only (2) and (3) are true.
3. Only (1) and (3) are true.
4. All are true.

Answer: 1. Only (1) and (2) are true.

Question 26. Select the mismatched pair.

1. Storage of pollen grains – 196 C
2. Pollen allergy-carrot grass
3. Chasmogamous flowers -Exposed anthers and stigmas
4. Xenogamy- self-pollination

Answer: 4. Xenogamy- self-pollination

Question 27. A typical angiospermous ovule is attached to the placenta using a stalk called X. The Body of the ovule fuses with X in the region called Y. Thus Y represents the junction between the ovule and funicle. Identify X and Y.

Answer: 1. Funicle   Hilum

Sexual Reproduction In Flowering Plants MCQ For NEET  Question 28. Match column I with column II and select the correct option from the codes given below.

1→A  2 →D  3 →B  4→C

1 →A  2 →D 3→ C 4 →B

1→ B  2 →C  3→ A  4 →D

1 →B  2 →A  3 →1  4→ D

Answer: 1. 1→A  2 →D  3 →B  4→C

Question 29. Given below are the events that are observed in an artificial hybridization programme. Arrange them in the correct sequential order.

1. Re-bagging
2. Selection of parents;
3. Bagging;
4. Dusting the pollen on the stigma;
5. Emasculation;
6. Collection of pollen from the male parent.

1. 2 → 3→ 5→ 6→ 4 → 1

2. 2→ 5 →3→ 6 →4 →1

3. 5 →2 →3 →6 →1 →4

4. 2 →3 →6 →4 →5 →1

Answer: 2. 2 →3 →5 →6 →4 →1

Sexual Reproduction In Flowering Plants MCQ For NEET  Question 30. Identify the different parts of a typical dicot embryo labelled as A. 11 and C and select the correct option.

1. Plumule Cotyledons Radicle
2. Radicle Cotyledons Plumule
3. Cotyledons Plumule Radicle
4. Cotyledons Radicle Plumule.

Answer: 1 . Plumule Cotyledons Radicle

Question 31. A typical example of cross-pollination is :

1. Wheat (Triticum)
2. Rice (Oryza saliva)
3. CLCotton (Gossypium)
4. Zea mays.

Answer: 4. Zea mays.

Question32. Continued self-pollination generation after generation, results in :

1. better progeny
2. pure line formation
3. formation of new varieties
4. None of the above.

Answer: 2. pure line formation

Question 33. Stigma is always sticky and rough in :

1. Anemophilous flower
2. Hydrophilous flowers.
3. Entomophilous flowers
4. All the above types of flowers.

Answer: 3. Entomophilous flowers

Question 34. The chief pollinators of our agro-horticultural crops are :

1. Butterflies
2. Moths
3. Beetles
4. Bees

Answer: 4. Bees

Sexual Reproduction In Flowering Plants MCQ For NEET  Question 35. The phenomenon of opening of flower buds is called :

1. Gcjmetogenesis
2. Sporogenesis
3. Anthesis
4. None of the above.

Answer: 3. Anthesis

Question 36. In wheat and sugarcane, pollination takes place by :

1. Wind
2. Water
3. Insects
4. Animals.

Answer: 1. Wind

Question 37. If water causes pollinatior^-it is called :

1. Anemophily
2. Hydrophily
3. Chiropterophily
4. Zoophily.

Answer: 2. Hydrophily

Question 38. Insect-pollinated flowers possess:

1. Smooth and dry pollen
2. A larger amount of pollen
3. Coloured corolla
4. Rough pollen.

Answer: 3. Coloured corolla

Question 39. Protandry is a condition in which :

1. Anthers mature after stigma
2. Anthers and stigmas mature at the same time
3. Anthers mature earlier than the stigma
4. Pollens of the same flower pollinate stigmas.

Answer:3.Anthers mature earlier than the stigma

Biology Sexual Reproduction in Flowering Plant Question 40.Cleistogamous flowers arc ;

1. Open male flowers
2. Open bisexual flowers
3. Male flowers which never open
4. Bisexual flowers which never open.

Answer: 4. bisexual flowers which never open.

Question 41. In Ficus the pollination is affected by :

1. Air
2. Water
3. Birds
4. Wasps.

Answer: 4. Wasps.

Question 42.Palynpld’gy deals with the study of:

1. Pollen grains
2. Chromosomes
3. DNA
4. Genes.

Answer: 1. Pollen grain

Question 43.When an anther dehisces towards the centre of the flower/it is called :

1. Montrose
2. Extras
3. Inserted
4. Exerted.

Answer: 1. Introse

Question 44. The lever mechanism is found in the pollination of:

1. Ipomoea
2. Euphorbia
3. Salvia
4. Vallisneria.

Answer: 3. Salvia

Question 45. When male and female parts of a flower mature at different times, it is termed:

1. Dichogamy
2. Heterostyly
3. Herkogamy
4. Monoclinic.

Answer: 1. Dichogamy

Biology Sexual Reproduction in Flowering Plant Question 46. Pollination by bats is known as :

1. Anemophily
2. Hydrophily
3. Chiropterophily
4. Ornithophily.

Answer: 3. Chiropterophily

Question 47. Cross-pollination is advantageous because it results in information of:

1. Weaker progen
2. Better progeny
3. Female offspring
4. Male offspring.

Answer: 2. Better progeny

Question 48. To avoid self-pollination, the pollen grains of some flowers have no fertilizing effect on the stigma of the same flower. This condition is :

1. Self sterility
2. Herkogamy
3. Dicliny
4. Dichogamy.

Answer: 1. Self sterility

Question 49. If the pollen of a flower falls on the stigma of another flower belonging to the same plant, it is :

1. Genetically self-pollinated
2. Ecologically cross-pollinated
3. Both and
4. None of the above.

Answer: 2. Ecologically cross-pollinated

Question 50. Malacophily is pollination by

1. Insects
2. Snails
3. Ants
4. Elephant.

Answer:2. Snails

Question 51. Which one of the following parts of the pistil receives the pollen during pollination?

1. Stigma
2. Ovule
3. Micropyle
4. Nucellus.

Answer:1. Stigma

Biology Sexual Reproduction in Flowering Plant Question 52. The following plant has pollination above ground but its fruit develops underground.

1. Sweet potato
2. Solarium tuberosum
3. Onion.
4. Arachis hypogea.

Answer:4. Arachis hypogea.

Question 53. Pollinia are sac-like structures in which :

1. Anther lobes are present
2. Anthers lose their individuality
3. Pollen grains get fused in a mass.
4. yellow substance is secreted.

Answer:3. Pollen grains get fused in a mas

Question 54.Allog. um, though the biotic agency is called :

1. Entomophily
2. Ancmophily
3. Hydrophily
4. Both 1 and 2.

Answer:1 .Entomophily

Question 55. Chiropterophilous flowers possess :

1. coloured petals
2. Abundant nectar
3. Hydrophily
4. Less pollen.

Answer:2. Abundant nectar

Question 56. pollination of pinus is:

1. Entomophilous
2. Anemophilous
3. Hydrophily
4. Malacophily.

Answer:2. Anemophilous

Question 57. In Salvia, pollination takes place by :

1. Animals
2. Insects
3. Air
4. Water.

Answer:2. Insects

Sexual Reproduction in Flowering Plants NEET Question 58. The entry of the pollen tube into the embryo sac through the integuments is termed as :

1. Porogamv
2. Chalazogamy
3. Monogamy
4. Both  1  and 2.

Answer:3. Mesogamy

Question 59.512 microspores will be formed following meiosis How many spores?

1. 16
2. 64
3. 128
4. 256.

Answer:3. 128

Question 60. An example of triploid tissue is :

1. Onion leaf
2. Onion root
3. Maize endosperm
4. Fern prothallus.

Answer:3. Maize endosperm

Question 61. Triploid plants can be obtained from the culture of :

1. Pollen
2. Endosperm
3. Megaspore
4. Ovule.

Answer:2. Endosperm

Question 62.After fertilization synergids and antipodal cells form :

1. Embryo
2. spore
3. Endosperm
4. None of the above.

Answer:4. None of the above.

Question 63. Pollen grain in angiosperm develops from :

1. Endothecium
2. Tapetum
3. Sporogenous tissue
4. Middle layer.

Answer:3. Sporogenous tissue

Sexual Reproduction in Flowering Plants NEET Question 64.The nucellus of the ovule is :

1. Haploid
2. Diploid
3. Triploid
4. Polyploid.

Answer:2. Diploid

Question 65. In the case of angiosperms, the embryo sac represents :

1. Female gametophyte
2. Sporophyte
3. Male gametophyte
4. All the above.

Answer:1. Female gametophyte

Question 66. The other wall consists of four wall layers where :

1. The tapetum lies just inner to endothecium
2. Middle layers lie between endothecium and tapetum
3. Endothecium lies inner to middle layers
4. The tapetum lies next to the epidermis.

Answer:2. Middle layers lie between endothecium and tapetum

Question 67. Emasculation is achieved by :

1. Removal of anthers
2. Removal of stigma
3. Removal, of gynoecium
4. Removal of calyx and corolla.

Answer:1. Removal of anthers

Question 68. A (lower pan whose primary MLC is protection, is the :

1. Stamen
2. Ovary
3. Sepal
4. Embryo sac.

Answer:3. Sepal

Question 69. In a fully developed male gametophyte, the number of nuclei is:

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

Answer:3. Three

Sexual Reproduction in Flowering Plants NEET Question 70. The mature anther wall comprises an epidermis followed by a layer of radially elongated cells with fibrous bands of callose called endothecium whose function is :

1. Nutrition
2. Protection
3. Mechanical
4. Dehiscence.

Answer:4. Dehiscence.

Question 71. The innermost layer of the anther is the tapetum whose function is

1. Dehiscence
2. Mechanical
3. Nutrition
4. Protection.

Answer:3. Nutrition

Question 72. Ovule represents :

1. Hierpsporangium
2. Megasporangium
3. Gametophyte
4. Embryo.

Answer:2. Megasporangium

Question 73. The female plant is diploid and the male plant is tetraploid. Find out the correct match.

Answer: 1. 3n  4n  2n  n  2n  4n

Question 74. Mature ovules are classified based on the funiculus. If the micropyle comes to lie close to the funiculus the ovule is termed as :

1. Orthotropous
2. Anatropous
3. Amphitropous
4. Campylotropous.

Answer:2. Anatropous

Question75. In a bisexual flower when the gynoecium matures earlier than another, it is called:

1. Protandry
2. Protbgyny
3. Herkogyny
4. None of the above.

Answer:2 .Protbgyny

Sexual Reproduction in Flowering Plants NEET Question 76. Plants which flower only once in life are termed as:

1. Polycarpic
2. Monocarpic
3. Pericarpic
4. Leucas.

Answer:2. Monocarpic

Question 77. Translators are found in :

1. Calotropis flower
2. Hibiscus
3. Vinca flower
4. Leucas.

Answer:1. Calotropis flower

Question 78. When the micropyle, chalaza and hilum he in a straight line, the ovule is said to be :

1. Anatropous
2. Orthotropous
3. Amphitropous
4. Campylotropous.

Answer:2. Orthotropous

Question 79. Double fertilization was first described by :

1. Hofmeister
2. Nawaschin
3. Strasburger
4. Leeuwenhoek.

Answer: 2. Nawaschin

Question 80. The secondary nucleus after fusing with one of the male gametes develops into :

1. Embryo
2. Seed
3. Endosperm
4. Fruit.

Answer: 3. Endosperm

Question 81. The fusion of the male gamete with the secondary nucleus of the embryo sac is the process of:

1. Fertilization
2. Double fertilization
3. Parthenocarpy
4. Parthenogenesis.

Answer: 2. Double fertilization

Question 82. The fertilization occurs in the :

1. Ovary
2. Ovule
3. Embryo sac
4. Nucellus.

Answer: 3. Embryo sac

Important MCQs on Reproduction in Flowering Plants Question 83. In the diagram given above, parts labelled as *P\ ‘Q\ ‘R’,‘S’, ‘T\ ‘U’ are respectively identified as

1. synergids, polar nuclei, central cell, antipodal cell, filiform apparatus and egg.
2. polar nuclei egg, antipodal cell, central cell, filiform apparatus and synergids.
3. egg, synergids, central cell, filiform apparatus, antipodal cell and polar nuclei
4. central cell, polar nuclei, filiform apparatus, antipodal cell, synergids and egg.

Answer: 1. synergids, polar nuclei, central cell, antipodal cell, filiform apparatus and egg.

Question 84. If an endosperm cell of an angiosperm contains 24 chromosomes, the number of chromosomes in each cell of the root will be :

1. 8
2. 4
3. 16
4. 24.

Answer: 4. 16

Question 85.In ovule meiosis occurs in :

1. Megaspore
2. Megaspore mother cell
3. Endosperm
4. Integument

Answer: 2. Megaspore mother cell

Question 86.The female gametophyte of a typical dicot at the time of
fertilization is :

1. 8-celled
2. 7-celled
3. 6-celled ‘
4. 4-celled.

Answer: 2. 7-celled

Question 87. Development of embryo sac from any cell of nucellus is called :

1. Apogamy
2. Apospory
3. Parthenogenesis
4. Sporogenesis.

Answer: 2. Apospory

Important MCQs on Reproduction in Flowering Plants Question 88. The method of fertilization (in an angiosperm) in which the pollen tube enters the ovule by way of micropyle is known as:

1. Chalazogamy
2. Porogamy
3. Microgamy
4. Syngamy.

Answer: 2. Porogamy

Question 89. Simple fruit develops from :

1. The single ovary which is simple
2. The single ovary which is a compound
3. The single ovary which may be simple or compound
4. None of the above.

Answer: 3 . The single ovary which may be simple or compound

Question 90. Parthenocarpic fruit is :

1. Fruit with immature seeds
2. Fruit, with mature seed
3. Developed without fertilization
4. Only seeds and no fruits.

Answer: 3. Developed without fertilization

Question 91. After fertilization, the ovary is converted into :

1. Embryo
2. Endosperm
3. Seed
4. Fruit.

Answer: 4. Fruit.

Question 92. Perisperm in angiosperm seed is derived from :

1. Nucellus
2. Endosperm
3. Integuments
4. Antipodal cells.

Answer: 1. Nucellus

Question 93. The entry of the pollen tube into the embryo sacs through the chalaza is called :

1. Porogamy
2. Monogamy
3. Chalazogamy
4. C either A or B.

Answer: 3. Chalazogamy

Question 94.Ovule is ategenic in :

1. Helianthus
2. Pea
3. Santalum
4. Brassica.

Answer: 3. Santalum

Question 95. Vivipary is of common occurrence in

1. Halophytes
2. xerophytes
3. Hydrophytes
4. Psaminophytes.

Answer: 1. Halophytes

Sexual Reproduction In Flowering Plants MCQ For NEET Question 96. Polyembryony commonly occurs in < 0

1. Turmeric
2. Tomato.
3. Potato
4. Citrus.

Answer: 4. Citrus.

Question 97. The main embryo develops from the structure formed as a result of fusion of:

1. Two polar nuclei of embryo sac
2. Egg cell and male gamete
3. Synergid and male gamete
4. Male gamete and antipodals.

Answer: 2. Egg cell and male gamete

Question 98. The function of an obturator for any ovular structure is to :

1. Nourish ovule
2. Nourish pollen grains
3. Guide pollen tube towards micropyle
4. Keep the ovule alive.

Answer: 3. Guide pollen tube towards micropyle

Question 99. The term xenia denotes the effect of the following:

1. Pollen on endosperm
2. Pollen on egg
3. Pollen on nucellus
4. Pollen on the seed coat.

Answer: 1. Pollen on endosperm

Question 100. Polygonum type of embryo sac is:

1. 8-nucleate, 7-celled
2. 8-nucleate, 8-celled
3. 7-nucleate, 7-celled
4. 4-nucleate, 3-celled.

Answer: 1. 8-nucleate, 7-celled

Question 101. Which of the following statements is true for the pollen tube :

1. It shows the growth of intent
2. It is composed of three non-cellular zones
3. It shows thigmotactic movement
4. It shows cytoplasmic streaming.

Answer: 1. It shows the growth of intent

Sexual Reproduction In Flowering Plants MCQ For NEET Question 102. Lire seed coat develops from the

1. Sepals
2. Ovary wall
3. Ovule wall
4. Endosperm.

Answer: 3. Ovule

Question 103. Which of the following is required for germination of
seeds?

1. Certain temperature conditions
2. Oxygen
3. Water
4. All the above.

Answer: 4. All the above.

Question 104. The fusion of egg with male gamete is called :

1. Syngamy
2. Apogamy
3. Autogamy
4. None of the above.

Answer: 1. Syngamy

Question 105. In angiosperms, the oospore on development produces :

1. Endosperm
2. Protonema
3. Embryo
4. Seed.

Answer: 3. Embryo

Question 106. A female gametophyte would be found in the :

1. Ovule
2. Stigma
3. Endosperm
4. Seed.

Answer: 1. Ovule

Question 107. Pollen grain gets nutrition fronts

1. Endothecium
2. Tape turn
3. Sporogenous sac
4. Middle layer.

Answer: 2 . Tape turn

Question 108 .The nucellus of the ovule is :

1. Haploid
2. Diploid
3. Triploid
4. Polyploid.

Answer: 2 .Diploid

Sexual Reproduction In Flowering Plants MCQ For NEET Question109 .The diagram given below shows ovules megasporogenesis and megagametogenesis in an angiosperm named Polygonum.

Reduction division takes place at which step?

1. Step 1
2. Step 2
3. Steps 2 and 3
4. Steps 3 and 4

Answer: 1. Step 1

Question 110. In the case of angiosperms, pollen grain produces :

1. Female gametophyte
2. Sporophyte
3. Male gametophyte
4. All the above.

Answer: 3. Male gametophyte

Question 111.Sexual reproduction in which morphologically and physiologically similar gametes fuse is termed as :

1. Plasrnogamy
2. Anisogamy
3. Isogamy
4. Oogamy.

Answer: 3. Isogamy

Question 112. A normal plant suddenly started reproducing parthenogenetically. ‘The number of chromosomes of the second generation as compared to the parent plant will be :

1. Double
2. Half
3. One fourth
4. same.

Answer: 4. same.

Sexual Reproduction In Flowering Plants MCQ For NEET Question 113. If cotyledons remain below soil during germination, it is:

1. Rhypogeal germination
2. vivipary
3. Epigeal germination
4. None of the above.

Answer: 1. Rhypogeal germination

Question 114. Seeds are dispersed by :

1. Water
2. Living organism
3. Wind
4. All the above.

Answer: 4. All the above.

Question 115. Micropyle of ovule allows entry of:

1. Pollen tube
2. water
3. Wind
4. All the above.

Answer:  1. Pollen tube

Question 116. When seeds develop without meiosis and syngamy, the phenomenon is :

1. Parthenogenesis
2. Parthenocarpy
3. Agamospermy
4. Apogamy.

Answer: 4. Apogamy.

Question 117. The inner integument of the majority of the dicot seed is :

1. Hypocotyl
2. Scutellum
3. Funicle
4. Tegmen

Answer: 4. Tegmen

Question 118. Epigeal seed germination is found in :

1. Wheat
2. Castor
3. Pea
4. Maize.

Answer:  2. Castor

Sexual Reproduction in Flowering Plants NEET Question 119. Which of the following statements is correct?

1. In angiosperms, the main plant body is gametophytic and
   sporophytic generation is reduced
2. In angiosperms, the main plant body is sporophytic and gametophytic
   generation is altogether absent
3. In angiosperms the main plant body is sporophytic and the male and
   female gametophytes are represented by pollen and embryo sacs respectively
4. In angiosperms, the ovules and anthers are gametophytic whereas all other parts are sporophytic.

Answer: 3. In angiosperms the main plant body is sporophytic and the male and female gametophytes are represented by pollen and embryo sacs respectively

Question 120. Monosporic, 8 nucleate embryo sac is called :

1. Allium type
2. Oenothera type
3. Polygonum type
4. Peperomia type.

Answer:  3. Polygonum type

Question 121. An example of triploid tissue is :

1. Fern prothallus
2. Cycas ovule
3. Lily endosperm
4. Moss capsule.

Answer : 3 . Lily endosperm

Question 122.If soaked pea seeds are kept in four separate flasks, the best
germination will be in the flask having :

1. Oxygen
2. Carbon dioxide
3. Nitrogen
4. Water.

Answer: 1. Oxygen

Question123.Which of the following plants are likely to have a wider range of distribution?

1. Those distributed by seeds
2. Those distributed by spores
3. Those distributed vegetatively
4. Those distributed by fruits.

Answer: 1. Those distributed by seeds

Question 124. In albuminous seeds, the food is stored mostly in :

1. Cotyledons
2. Endosperm
3. Testa
4. Plumule.

Answer: 2. Endosperm

Question125.For the formation of 50 zygotes in a tobacco plant, the minimal number of meiosis involved would be:

1. 59
2. 63
3. 99
4. 109.

Answer: 2. 63

Question 126.In angiosperms normally after fertilization:

1. The zygote divides earlier than the primary endosperm nucleus
2. The primary endosperm nucleus divides earlier than the zygote
3. TO both the zygote and primary endosperm nuclei divulge simultaneously
4. Both the /vote and primary endosperm nuclei undergo a resting period.

Answer: 2. The primary endosperm nucleus divides earlier than the zygote

Question1 27. Match the two columns and select the correct answer

P Q  R S

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

Answer: 2. 2  3  4  1

Sexual Reproduction in Flowering Plants NEET Question 128. Match column-1 with column-2 and select the correct option from the codes given below.

1. 1→ B  2 →D  →3→ A  4→ 3
2. 1 →B  2→ D  3 →C  4 →A
3. 1 →C  2→ B  3 →A  4 →D
4. 1 →D  2 →C  3→ B  4 →A

Answer: 1. 1→ B  2 →D  →3→ A  4→ 3

NEET Biology Blood Circulatory System Circulation Of Fluids

Types of circulation. The circulatory system is the transport system of the body and circulating fluid transports nutrients, respiratory gases, metabolic intermediates and hormones, (informational molecules) to all parts of the body.

• It maintains homoeostasis, uniformity of heat etc. all over the body.
• It acts as the centre for the defence system.
• It carries metabolic intermediates For Example lactic acid (muscle to liver), and information molecules (hormones).
• The circulating fluid also distributes water, H+, chemicals and heat uniformly all over the body parts.
• Circulation may be intracellular or extracellular
• Intracellular circulation takes place inside the cell For Example In Amoeba and Paramecium it is called cytoplasmic movement and cyclosis respectively.
• Extracellular circulation takes place outside the cell.
• Extraorganismic circulation is also called water circulation For Example Leucosolenia (sponge), Hydra etc.

A gastrovascular cavity in acoelomate aquatic invertebrates performs the function of an internal circulatory system.

Read and Learn More NEET Biology Notes

• Coelomate invertebrates do have a circulatory system, which may be closed or open type.
• Intraorganismic circulation. In this, body fluids circulate in the body For Example blood and lymph.
• Blood vascular system. In this case, the circulating fluid is blood.

Components of the blood vascular system

1. Blood
2. The heart
3. The blood vessels

Blood Circulatory System In Animals NEET Notes

Lymphatic system. In this case, the circulating fluid is lymph.

• Parenchymal circulation takes place in Platyhelminthes in special tissue-the parenchyma.
• Body cavity circulation takes place in the body cavity, a watery fluid, called hydro-lymph, without a respiratory pigment as in Nematodes, ectoprocts and rotifers.
• Closed type of circulatory system. Blood flows in closed vessels and the heart For Example, vertebrates as in man.
• Blood vessels form a complete circuit in the body, carrying blood to and from the organs. Free haemo coelomic spaces outside the system are generally reduced or absent altogether.
• Open type of circulatory system. Blood does not flow in closed vessels but is present in the body cavity For Example, arthropods and molluscs have an open type of circulatory system.

In the open type, the blood is pumped by the heart into blood vessels that open into blood sinuses (spaces). There is no capillary system.

The circulatory system of cockroach. It is open type. It consists of 13 chambered heart t modified dorsal blood vessel), colourless blood, and haemolymph, comprising plasma and white corpuscles termed haemocytes Haemocoel is divided into three sinuses

1. Pericardial sinus (Dorsal sinus)
2. Periviscreal sinus
3. perineural Sinus

The flow of blood is kept in constant flow by contraction of alary muscles.

NEET Biology Blood Circulatory System Blood

Haematology. Study of the formation, composition, function and diseases of the blood.

• Blood. Blood is a fluid (mesodermal origin) connective tissue. Blood is a transporting material of the body and transports 0₂, salts, vitamins, hormones, food substances etc.
• To all parts and cells of the body and collects metabolic wastes (CO₂, and NH3) from them and passes them to the lung and kidneys respectively for giving out. The blood contains 45% corpuscles (formed elements) and 55% plasma (fluid).

Corpuscles. (R.B.C., W.B.C. and platelets)

R.B.C. Their number is about 5.5 million per mm3 in males and about 4.8 million per mm- in females, which can be counted by haemocytometer. Each R.B.C. is biconcave, devoid of nucleus, mitochondria and centriole in mammals (except in camel and sloth where it is nucleated).

• The cell metabolism is maintained by 2-3 diphosphoglycerol (DPG), which is three times more in R.B.C. Each R.B.C. is 7- 8 pm in diameter, 3|im in width, with an average volume of 87 pm3 and can carry 109 mols of 0-> with it from lung to tissue.
• The colour of R.B.C. is due to respiratory pigment—haemoglobin (Fe-base), present in most of the vertebrates; Haemocyanin (Cu-base) – blue, present in Mollusca and Crustacea; Haemoerythrin (Fe-base) – Red, dissolved in plasma, present in siphunculus and branchiopods and Chlorocrurin (Fe-base) green dissolved in plasma present in polychaetes.
• The erythrocytic sedimentation rate (E.S.R.) in man is 6-10 gm/100 ml of blood in the first hour (during infection and disease the R.B.C. become lighter and E.S.R. is decreased). E.S.R is determined by Wintrobe’s tube and also by the Western blotting method.
• R.B.C. is 60% water and 40% solid. Its percentage in the following is as – haemoglobin— 29. phospholipids—4, cholesterol—19, fats—07, glucose —06, non-protein nitrogen—044; Urea —11 and inorganic salts 0-7 to 1%.
• Haemoglobin. It consists of 1 molecule of heme (iron porphyrin) and 4 molecules of globulin (protein). The average haemoglobin percentage in males is 16 gms and in females 14 gm/100 ml of blood (at birth it is 23 gm/100 ml of blood). The percentage of haemoglobin decreases during illness or in loss of blood and causes anaemia in animals.
• W.B.C. White blood corpuscles are nucleated and show diapedesis (amoeboid movements and can pass through capillaries into lymphatic spaces as wandering cells). W.B.C. number varies from 5000 to 9000/Cubic nun.
• In stress, strain, infection and disease, their number is increased as they do phagocytosis and work as organs of offence and defence besides helping in healing the wounds. They are of two types :
• Agranulocytes. 20-25%, without azurophilic granules (lymphocyte, 6-lOj.tm in diameter, monocytes- 3-8%, 9- 12(im in diameter) Monocytes are largest W.B.C., kidney-shaped excentric nucleus.
• Granuloolev 75-80%. the nucleus is longitudinal (two or more lobes). They are of llwee i\pcs Kosinophils 4%). bilobed nucleus, sentinel by acidic dyes and spherical in shape Rasophils tO.5-2%) S-shaped nucleus, stained in basic dyes.
• Neutrophils (60-70%). nucleus, show amoeboid movement highest, in number and physiologically not important. stained by natural dyes.
  • Plasma. It contains 90% water and 10% other substances like :
  • Proteins. 5.5 to 7.6*7- (albumin 3.3 to 5.6%. globulin — 1.6 to 3.4%, fibrinogen is about 2 to .4%).
  • Organic Constituents. 1-2% non-nitrogenous fat, carbohydrates lipids and nitrogenous urea, uric acid, creatinine, ammonia, amino acids, and xanthine.
  • Inorganic Constituents. Chlorides, bicarbonates, sulphates and phosphates of K, Na. Ca. Mg and Fe.
  • Enzymes. Lipase, amylases, protease, esterase, nuclease and oxidase etc.
  • Hormones. Thyroxine, insulin, pituitrin, adrenaline, estrogen androgen etc.
  • Gases. 0₂, CO₂,. N₂,

The plasma is the transport medium of blood, even some 02 is also transported by it.

Blood Circulatory System In Animals NEET Notes

Blood platelets

1. Number. The platelets are fewer than the red corpuscles and more than the white corpuscles in number. There are about 250,000 platelets in a cubic millimetre of blood. An increase and decrease in the number of platelets are known as thrombocytosis and thrombocytopenia respectively.
2. Structure. The platelets are flat, non-nucleated fragments of large cells in the bone marrow, rather than true cells. They. are bounded by a membrane and contain a few organelles and secretory granules in the cytoplasm.
3. They have at the centre a group of basophilic granules, which give the appearance of a nucleus. At the site of injury, the platelets release platelet factor or thromboplastin that helps in blood clotting.
4. Formation. The platelets are formed in the red bone marrow. Their formation is known as thrombopoiesis.
5. Life Span and Disposal. The platelets survive for 3 – 7 days only. They are disposed of by phagocytosis in the blood itself.
6. Spindle Cells or Thrombocytes. These are biconvex, nucleated cells with granular cytoplasm. They are found in vertebrates other than mammals. The spindle cells aid in the clotting of blood like the platelets of mammals.

NEET Biology Blood Circulatory System Coagulation Of Blood

Soluble blood protein fibrinogen (dissolved in plasma) is changed into fibrous protein. Fibrin entangles the platelets and corpuscles and the blood clots. This clotting involves various factors :

1. The place of injury produces thromboplastin. Under the influence of thrombokinase, the phospholipid is given by rupturing platelets, Ca + + ions, and antihero-philic factor.
2. Prothrombin and heparin. Produced by the liver are present in blood. Heparin acts as an anticoagulant. Under the influence of thromboplastin, the prothrombin is broken into thrombin and heparin.
3. Thrombin in the presence of Ca ++ ions acts on fibrinogen (a soluble protein present in the blood) and converts into fibrous protein fibrin. Fibrin makes a mesh of delicate fibres and platelets entangle them to form a clot.
4. Blood stored in the blood bank is added with oxalate, and carbonate, which precipitate v/ith Ca and blood does not coagulate due to suppression or removal of calcium salts.

Factos in coagulation are numbered up to 13.1 — Fibrinogen; II — Prothrombin, Vit K; III — Thromboplastin; IV — Calcium ions, V — Proaccolerin; VI — denied; VII — Proconvertin; VIII — Anti-haemophilic globulin (AHG) IX — Christmas factor (platelets factor II), X — Stuart factor, XI — Plasmo thromboplast Antecedent (PTA) XII — Hegeman’s factor (contact factor), XIII — Fibrin stabilizing factor (FSH factor).

• If blood does not clot, it is called bleeder’s disease ‘haemophilia’.

NEET Biology Blood Circulatory System Theories of Blood Coagulation

1. Best and Taylor’s theory. According, to this theory prothrombin is essential for clotting.
2. Howell theory. Ca₂ + ions play an important role in clotting
3. Fuel and Spiro theory. Thrombokinuse is important for clotting.
4. Cascade theory by Macferlanc (Most recent)
5. According to Cascade’s theory, there are ID factors presently in blood dolling.
6. Best and Taylor gave 4 factors of blood clotting
7. Howell worked upon Limulus.

Encephalic Thrombus – Formation of Thrombus in blood vessels of the brain

1. The mammalian circulation route is a closed-type circuit consisting of two main subsystems:
2. Pulmonary circulation constitutes 16% of total blood (7% in the heart and 9% in pulmonary vessels.)
3. The route of blood is – Right Auricle→Right ventricle → Pulmonary aorta→ Lungs Pulmonary vein →Left auricle.

Systemic Circulation consists of 84% of total blood (64% in veins, 15% in arteries and 5% in capillaries and the route of blood are:

1. Left auricle→ Left ventricle→Systemic aorta → Organs or tissues → Veins→ Right auricle.
2. Systemic veins are called blood reservoirs.
3. Other sub-systems are also considered as part of systemic circulation. These are :

Cerebral circulation. The brain gets blood through four (two external and two internal) carotid arteries, but at the base of the brain these fuse to form a circle of Willis, from which arteries branch off to supply the brain.

Blood Circulatory System In Animals NEET Notes

Hepatic circulation. The liver receives blood from two sources, the hepatic portal vein and the hepatic artery and the mixed blood leaves through the hepatic vein.

1. Blood also remains stored in blood sinuses within the liver.

Coronary circulation. Supply of blood to the heart muscle itself and left coronary arteries arise from the base of the systemic aorta and supply to respective parts of the heart.

Blood vascular system. It is a closed type and consists of a triangular muscular pumping organ heart, tube-like blood vessels (arteries, veins and capillaries) and transporting medium blood which acts as carriers.

NEET Biology Blood Circulatory System Types of Hearts based on Morphology

Pulsating hearts. Simple blood vessels with a relatively heavy muscular wall, which contract in peristaltic waves For Example Annelids, and Amphioxus.

1. Tubular hearts. A pulsating vessel is highly developed and present in the pericardial cavity or sinus For Example Arthropods, some tunicates.
2. Ampullar accessory hearts. These are booster pumps which provide sufficient driving force to pump blood through some peripheral regions of circulation For Example Crustacean, insects and some cephalopods.
3. Chambered hearts. The heart is thick-walled, muscular and chambered vertebrates, molluscs.

NEET Biology Blood Circulatory System Heart

It is a hollow, muscular pumping organ formed of cardiac muscle fibres and beats spontaneously and rhythmically throughout life. It is enclosed in a double-walled pericardium. It is a three-layered

1. Endocardium
2. Myocardium
3. Pericardium (Heart lies in it ). The heart is four-chambered with left and right auricles and ventricles. The walls of the ventricle are thicker than the auricle. The wall of the left ventricle is 3-6 times more thicker than the right ventricle.

Cardiac valve. Prevents the backflow of blood.

• Bicuspid or Mitral valve in between left auricle and left ventricle and tricuspid valve in between right auricle and right ventricle (Bicuspid made two membranous cusps and tricuspid with three cusps.)
• The tricuspid valve is a distinguishing characteristic of the mammalian heart. (In lower chordates the valves are muscular Jtujt in mammals they become membranous.)
• The lower border of valves is provided, with many slender but strong Chordae tendineae which at their other ends are connected either directly to the walls of ventricles and interventricular septum or to papillary muscles of the ventricle.
• A modified blood vessel, made of cardiac muscles (= myogenic) for pumping blood, mesodermal in origin.

1. In early forms (fishes) it is like a straight tube with tandem chambers :
2. sinus venosus → auricle →ventricle → truncus arteriosus.
3. Auricles and ventricles are true chambers the other two are auxiliary chambers.
4. In fishes, it is two-chambered (1 auricle + 1 ventricle) and. called a ‘venous heart’ since only venous blood flows through it.

From Amphibians to mammals it is first like muscular structure with auricle (thin-walled) and ventricle (thick-walled) as main chambers.

• The anterior broader end (auricle) is the base and the narrow posterior end (ventricle) is the apex.
• A distinct line of depression between the mile and ventricle is economy selects,
• Enclosed within two layers of pericardium. It is situated in the mediastinal space of the thorax.
• Histologically the outer layer is the epicardium followed by a thick muscular myocardium and lining of the endocardium.

The blood supply of the tissue is made by coronary circulation.

Blood Circulatory System In Animals NEET Notes

NEET Biology Blood Circulatory System Opening And Valves Of Heart

1. The tricuspid valve is present in the right auriculoventricular aperture.
2. A bicuspid valve is present in the left auriculoventricular aperture.)’
3. Semilunar valves are present between ventricles and aortic arches.
4. The valve of Thebesius guards the opening of coronary sinus v;
5. Haversian valve is present on the end of the opening of precavals.

Eustachius valve: present on the opening of the postcard.

Foramen of Pcnizee: It is the aperture that connects two ventricle

Foramen of Ovale: The aperture present between two auricles in the embryonal stage.

Fossa ovalis: It is the depression in the interauricular septum of the heart of an adult.

NEET Biology Blood Circulatory System Heart Beat

The rate of heart beat in man varies from 50 to 100 i.e. ± 72 beats per minute. The rate of females’ heartbeat is faster than that of males.

• It is the number of heartbeats per minute (72 in a man);
• Directly proportional to temperature and physical activity; becomes double with the rise of every 10°C but, ceases at 44°C.
• Ca++ accelerates the heart rate while Na+ and K+ make it slow.
• Increases also due to emotions, feelings, love, fear, pain anger, etc.

It is inversely proportional to the body weight of animals, as shown in the box.

NEET Biology Blood Circulatory System Cardiac Cycle

• Arterial systole – 0.1 sec. arterial diastole 0.762 see to 0.862 see. Ventricular systole 0.379 sec: Ventricular diastole- 0.483 sec to 0.862 sec. Auriculo-ventricular interval 15 seconds.
• Factors influencing heartbeat. Size of body, age, physical Fitness etc., lower the rate, heart beat, whereas muscular work, temperature, eating, bath, high altitude etc. increases the heart beats 100-150 beats/sec.
• Heartbeats can be recorded on a kymograph, the process is called kymography. Besides, sympathetic nerves accelerate the metabolic rate i.e. the heartbeat, respiration etc. while the parasympathetic nerves do the opposite work, hence’ they protect the heart.
• lung and other vital organs from overwork and excessive response to stimuli. Transmission of heartbeat. Heart is connected with the central nervous system by two nerves (1) Vagus (autonomic) (2) Cervical (sympathetic) Heart’s action is automatic (.involuntary), i-e. it does not depend on outside impulses.
• Its impulse node lies within the heart, such a heart is known as a myogenic heart. It is also controlled by the nervous system, therefore it is neurogenic also. The hearts of amphibia, reptilia, aves and mammals are myogenic.
• In frogs – the sinus venosus beats first and passes inner stimulus to the auricle, which passes it to the ventricle which contracts. Contraction of the sinus venous is followed by the contraction of auricles and the ventricle undergoes diastole.
• Pace-maker or S A Node (Sinu-auricular node) lies in the wall of the right atrium (auricle) near the opening of the right precaval. In mammals, cardiac impulse originates in the SA Node, This is the first structure of the heart which becomes electrically negative.
• The impulse originated from here contracts both the auricles and causes a systole sound and systolic pressure i.e., 120 mm of Hg. From this node, the impulse is carried to the AV Node, which lies at the inter-auricular septum.
• The AV Node gives rise to a bundle of nerve fibres called the Bundle of this. The fibres bifurcate at the extremity of the ventricle and form the Purkinje fibres, which spread in both the ventricles. The AV Node causes contraction of the ventricle and a diastolic sound and diastolic pressure i.e. 80 mm of Hg.
• The SA Node and AV Node produce the impulses at the difference of 10-15 seconds, which is called the rest period. A healthy person’s heart has 75 beats per minute and pumps 5 litres of blood per minute. A 50-year-old man’s heart on average beats about 2 billion times and pumps about 13 crore litres (1 lakh 30 thousand tons).
• Nerve Supply to the Heart. In addition to the intrinsic stimulation of the myocardium described above, the heart is influenced by nerves originating in the cardiac centre in the medulla oblongata which reach the autonomic nervous system. These are the parasympathetic and sympathetic nerves and they are antagonistic to one another.
• The vagus nerves (parasympathetic) try to slow the rate at which impulses are produced by the sinoatrial node, therefore decreasing the rate and force of the heartbeat.

The sympathetic nerves tend to speed up the rate of impulse production by the sinuatrial node, thus increasing the rate and force of the heartbeat.

1. The rate of the heartbeats is the result of a fine balance of sympathetic and parasympathetic effects. It is usually decreased during rest and increased during excitement, exercise and when the blood is decreased.
2. Hormonal regulation. Hormones from the adrenal medulla viz. Epinephrine accelerates the heartbeat at the time of emergency whereas norepinephrine does so under normal control.

Open And Closed Circulatory Systems NEET Biology

Ionic regulation. According to Ringer, inorganic ions such as Ca⁺4^– and K⁺ also control the activity of the heart. High K⁺ follow a diastolic arrest while high Ca₄ is a systolic arrest ‘clearly in frog heart. The reverse is true in many invertebrates and vertebrates according to Er and Brown (1961).

NEET Biology Blood Circulatory System Blood Vessels

1. Angiology is the study of blood vessels.
2. father of Angiology = William Harvey
3. Blood Vessels—Arterioles are ultimate fine branches of arteries having 0.2 mm diameter.
4. Artery– 15% to 20′, V- blood is present in the aorta and arteries = 900 ml.
5. 50% blood is present in capillaries = 150ml.
6. 70 % to 75% blood in large veins.

Capillaries—0.5 to .01 mm in dia. The average diameter is about 0.01 mm.

1. Ultimate branches of blood vessels (Malpighi-1661) are made of only simple squamous epithelium, the endothelium connects the arterial and venous parts of the circulation.
2. Maximum length of branches 0.5 to I mm and diameter of 7.5 p to 9
3. The total length of the human body is about 60,000 miles (or 96,000 km) and its total surface area is 500 nr,
4. The number of capillaries in tissue is directly proportional to their activity.
5. The more active organ has more capillaries (skeletal muscle 15 lakh/inch2) while no capillaries in the lens of the eye.
6. The distribution of blood in the various capillary beds is regulated by sphincters. Highest level of amino acids-Hepatic portal vein.

The lowest level of amino acids the hepatic vein.

1. Veins. In veins, the muscular and elastic tissues are less developed while connective tissues are more developed.
2. Venules. Ultimate fine branches of veins. Special type of blood vessels.
3. Arteriovenous Anastomosis. Arterioles are connected with venules directly. These open at too low a temperature for retaining heat.
4. They are found at the extremities like lips, pinna, tongue, fingertip, eyelids, nose etc., this helps in preventing heat loss.
5. Blood sinuses are the blood spaces replacing capillaries in the liver, spleen bone marrow etc. with even thinner walls,
6. Sinusoids. The arteries and veins are connected by way of irregular anastomosing vessels which are lined with discontinuous epithelium having phagocytic cells.
7. Rete Mirabilia. Arteries or veins divide into vessels which are as small as capillaries and reunite to form arteries or veins For Example, Glomeruli in the kidney.
8. Portal vein. A vein which collects blood from an organ and on its way to the heart divides into a network of capillaries in an intermediate organ.
9. Vasa vasorum are the vessels within the walls of the main vessels.

Open And Closed Circulatory Systems NEET Biology

NEET Biology Blood Circulatory System Portal System

1. A vein that carries blood from one capillary network to another is called a portal vein.
2. Frog has both a renal portal system and a hepatic portal system.
3. The renal portal system is absent in mammals, only the hepatic portal system is present.
4. The hepatic portal vein receives blood from gastrointestinal organs and the spleen and delivers it to sinusoids of the liver.
5. Hypophyseal portal system. Blood from the hypothalamus is collected by the hypophyseal portal vein which ends in the anterior pituitary.

NEET Biology Blood Circulatory System Blood Pressure

1. The pressure exerted by the blood on the walls of blood vessels is called blood pressure (BP).
2. Is the result of the sum of.
3. Osmotic colloidal pressure of blood
4. Elastic recoil of blood vessel’s wall and
5. Pumping force of the heart.

• First measured by British physiologist Stephan Hales (1733) in the carotid artery of the mare.
• In humans, it was first measured by Vaivre (1856) using a Ludwig mercury manometer.
• Riva Rocci (1896) discovered a sphygmomanometer, the instrument to measure B.P.
• In adults, the normal BP is 120/80.
• 120 mm of Hg is systolic pressure during contraction of ventricles, and 80 mm of Hg is diastolic pressure during relaxation of ventricles.
• In children, the BP is low as compared to adults.
• In old age, the average BP is 150/90, as the arterial wall becomes less elastic.

The chemicals which are vasodilators decrease blood pressure while vasoconstrictors increase blood pressure. Histamine is a vasodilator and adrenaline is a vasoconstrictor.

NEET Biology Blood Circulatory System Pulse

1. Pulse is a wave of distension, i.e., a rhythmic expansion and relaxation (not contraction) of arteries.
2. PI use is felt at the radial artery of the wrist.
3. With the help of a pulse, the heartbeat can be measured.

NEET Biology Blood Circulatory System Pulse Pressure

1. It is the difference between systolic and diastolic pressure.
2. In normal adults, the value of pulse pressure is 40 mm of Hg (120 mm- 80 mm).

NEET Biology Blood Circulatory System Heart Sound

During each cardiac cycle, the heart generates four sounds; however, only the first and second sounds are audible using a stethoscope. The following noises are delineated below: Closure of the Bicuspid and Tricuspid valves.

The method of listening to heart sounds is known as auscultation.

First Sound (Sj:

The phenomenon primarily results from the closure of the semilunar valves in the systemic and pulmonary aorta at the conclusion of ventricular systole, coinciding with the T wave on the ECG.

1. It resembles LUBB.
2. It has an extended duration.
3. It is a lower frequency (low pitch).
4. The volume is increased.

The second heart sound (S2):

2 nd sound (Sa) Occurs with the closure of the semilunar valves of the systemic and pulmonary aorta after ventricular systole, coinciding with the T wave of the ECG. This is attributable to:

1. It appears to resemble DUP.
2. It is brief.
3. It possesses more sharpness (high frequency).
4. It is less intense (low volume).

Open And Closed Circulatory Systems NEET Biology

NEET Biology Blood Circulatory System Stroke Volume (Stroke Output)

The volume of blood ejected out by heart per beat i.e. = 70 ml.

Cardiac Output (Heart Output). The amount of blood leaving the right or left ventricle per minute is known as cardiac output or minute volume. The major factor that directly influences the cardiac output is the amount of blood flowing into the ventricle during the diastole (diastolic intake).

• The volume of blood ejected per minute (heart rate x stroke volume i.e. 72 x 70 ml. = 5 litres); denoted as ml/100 gm of body weight/minute (man 5 – 10 ml; dog = 12-15 ml; cat = 65 – 70 ml). It increases by 20 to 30% at high altitudes.
• The entire blood of our body is circulated within just more than a minute and during exercise within less than 15 seconds. (In open-type circulation the velocity is very low i.e. in cockroaches it takes about 3-8 minutes for the entire blood to circulate)
• Cardiac output is not constant but varies with the physical activity.
• Vigorous exercise increases cardiac output to as much as 21L/min in a person in good condition.
• CO goes up to 35 L/min in world-class athletes.
• The difference between the maximum and resting cardiac output is called cardiac reserve.
• People with severe heart disease may have little or no cardiac reserve and little tolerance for physical exertion.

Of the blood pumped out (cardiac output) each minute by the heart, distribution to different parts are :

1. 10% to heart muscles
2. 15% to brain
3. 25% to the digestive system
4. 20% to kidneys
5. 30% to other organs

NEET Biology Blood Circulatory System Cardiac Index

The cardiac output per square metre of body surface area. This is about 3 litres in a man of 70 kg body weight with a body surface area of 1.7 meters.

NEET Biology Blood Circulatory System Pulse Rate

Following the ventricular systole a wave of distension (arterial pulse) passes along the arteries which is normally felt by putting a finger over the radial artery in the wrist. This wave is counted as the number of pulses per minute.

NEET Biology Blood Circulatory System Cardiac Activity

Includes all 3 components: cardiac rate, cardiac output and the force of contraction.

NEET Biology Blood Circulatory System Starling’s Law Of Heart

In stretched muscle, the force of contraction increases. Thus, if a higher amount of blood enters the heart its force of contraction increases proportionately.

1. Tachycardia, increased cardiac activity
2. Bradycardia decreases cardiac activity

Impulse conduction generates tiny currents in the heart, that spread through surrounding tissue to the surface of the body. If electrodes are properly placed on the body surface at specific places, the electric potentials generated by the heart during the transmission of impulses from an SA node through a conducting system can be recorded.

Such a record is called Electrocardiogram and the device used is an electrocardiograph. A normal ECG is composed of a P wave, A QRS complex and a T-wave.

1. Where P = depolarization of atrium indicates SA node activation wave
2. P-wave occurs slightly before the onset of Atrial contraction (systole).
3. QRS – waves (complex) begin slightly before the onset of ventricular systole.
4. T-wave occurs slightly before the end of ventricular systole.
5. PQ = Contraction of the auricle
6. QRS = depolarization of the ventricle.

Components Of Blood In Animals NEET Study Material

Q wave and ascent of R wave indicate the spread of impulse of contraction from AV Node,

1. Bundles of His, Purkinje fibres and ventricle muscles.
2. R-S and S-T interval = contraction of the ventricle.
3. T-Wave = Relaxation of ventricle.
4. ECG aids in the diagnosis of any irregularity in the heartbeat.

In rheumatic heart disease (valve damaged) and arteriosclerotic heart disease (due to the formation of plaque or calcification) there is inflammation of the atria and AV node, which results in the lengthening of the PR interval.

• When sore muscles receive insufficient oxygen (lesser supply of heart ischaemia), the SI segment is depressed and the l wave Is flattened.
• In acute myocardial infarction, the ST segment is elevated and Q & R waves are enlarged

In the case of hyperkalemia, the T wave is very tall and slender.

NEET Biology Blood Circulatory System Lymphatic System

The lymphatic system aids in maintaining optimal fluid equilibrium in tissues, conserving proteins, and eliminating bacteria and other particles from the tissues.

• The mammalian lymphatic system comprises lymphatic tubes and lymphoid organs.
• Lymph circulates unidirectionally from capillaries to progressively bigger lymphatic arteries, ultimately converging into a lymphatic duct that drains into a subclavian vein.
• Lymphoid nodules known as Peyer’s patches are located within the gut wall.
• Lymph is a transparent fluid contained within lymphatic tubes, originating from interstitial fluid.
• The lymphatic fluid in the arteries next to the gut postprandially is typically opaque due to the presence of chylomicrons.
• Lymph contains a lower concentration of antibodies compared to blood plasma.

Lymphocytes are produced in primary lymphoid tissue (thymus, embryonic liver, adult bone marrow) and migrate to secondary lymphoid tissue (spleen, lymph nodes, unencapsulated lymphoid regions of gut submucosa, respiratory and urinogenital regions).

1. Lymphoma is a tumour composed of lymph tissue.
2. Hodgkin’s disease is a malignant lymphoma of reticuloendothelial cells in lymph nodes and other lymphoid tissues.
3. Even a minor interference in the removal of tissue fluid will be noticed as tissue swelling a condition called oedema.

Lymph vessels. The lymphatic system helps to defend the body against diseases.

NEET Biology Blood Circulatory System Disorders Related To The Circulatory System

 The pressure exerted by the flow of blood on the walls of the arteries is tanned blood pressure.

1. Arterial blood pressure. The pressure of blood in the arteries is called arterial blood pressure.
2. Pulse pressure. The difference between systolic pressure and diastolic pressure is tanned pulse pressure.
3. Hypotension (Low blood pressure). It is caused due to permanent vasodilation of arteries or failure of the pumping action of the heart.
4. Hypertension (High blood pressure). It is caused by to rise in cholesterol levels, nervous strain, arteriosclerosis and kidney trouble.
5. Thrombophilia. A disorder of the haemopoietic system in which there is a tendency for the occurrence of thrombosis.
6. Thrombocytopenia. Fall in number of thrombocytes in blood.
7. Polycythemia. Increase in the number of RBCs in blood.
8. Leucopcnia. Abnormal fall in the number of WBCs in blood.
9. Leukaemia. It is a cancer of the blood in which bone marrow and lymph nodes produce more lymphocytes,
10. Diapedesis. Squeezing out of W.B.C. from blood capillaries.
11. Acapnia. Decreased amount of CO, in the blood.
12. Anaemia. It is a disorder resulting in either a decrease in R.B.C. or in the amount of haemoglobin. _
13. Sickle cell anaemia. It is a congenital haemolytic disease in which R.B.C. destruction occurs due to intracellular defects.
14. Pernicious anaemia. Macrocytic (large sized) R.B.C. with less 02 carrying capacity. It is due to an extracellular defect.
    • Haemoglobinomia is the disorder due to abnormal destruction of R.B.C. in the fluid and setting free Hb.
    • A marked decrease in concentration of plasma proteins is termed hypoproteinemia. Tachycardia. The heart beats rapidly.
15. Bradycardia. The heart beats slowly.
16. Dextrocardia. If the heart is placed towards the right side in the thoracic cavity an inborn defect.
17. Ectopia cordis. Sometimes heart becomes located outside in the thoracic cavity. The enlargement of the heart is termed cardiomegaly.
18. Cardiac arrest is a complete stoppage of a heartbeat.
19. Arteriosclerosis. It is also called the hardening of arteries, which results in arteries losing their elasticity because of the deposition of calcium salts in walls.
20. Heart block. The cardiac condition resulting from the defective transmission of impulses from the atrium to the ventricle is termed a heart block.
21. Heart murmur. The abnormal heart sound is produced as a result of defective valves. (Murmuring heart)
22. Patent Ductus Arteriosus. A congenital heart defect in which ductus arteriosus remains open. It must be closed by a surgical operation.
23. Angina. Heart pain of short duration is usually located in the front of the chest. Ischaemia (pronounced is-keema)—Inadequate flow of blood to a part of the heart caused by obstruction to its blood supply.
24. Myocardial infarction. Death of a part of the heart muscle following cessation of blood supply to it is an acute heart attack.
25. Haemolysis. It is the destruction of the blood corpuscles, causing the release of contained haemoglobin into the plasma.
26. Haemotoma. Blood is collected in the tissues outside the blood vessels, a common skin bruise due to blow.
27. Haemorrhage.Loss of blood from injured blood vessels.
28. Haemorrhoids. These are varicose veins in the walls of the rectum.
29. Oedema (Kdema). A Kval swelling is due to the accumulation of serous fluid in tissue caused by the defective circulation of blood or lymph.
30. In arborisation heaitbhvk. the defect lies in the Purkinjc’s fibres.
31. Angina Pectoris. Sevciv but temporary heart pain which is usually felt in the front of the chest and may pass into the arms.
32. Myocardial Ischaemia. Deficient blood supply to the heart muscle causes angina pectoris (G. Shein — to check, hame – blood)

NEET Biology Blood Circulatory System Blood Groups

The problem arises in the case of a condition when Rh- mother bears an Rh+ foetus. The second time if this happens it proves fatal to the foetus.

1. This condition is called Erythroblastosis foetalis; when maternal antibodies diffuse across the placenta into the foetal blood causing agglutination of red blood corpuscles, blockage of the capillaries and haemolysis leading to anaemia.
2. If one parent belongs to group A and the other to group B, the possible blood groups of children will be AB, A, 0. and B,0.
3. If a woman with blood group 0 marries a man with blood group AB, the blood group of their child will be either A or B
4. Persons with Blood group 0 are known as universal donors because their blood has no antigen in RBCs. They can donate blood to all the groups but can receive blood only from their own group.
5. Individuals with Blood group AB are called universal recipients because their blood has no antibodies in plasma. They can receive blood from any group but can donate blood to their own group.
6. DPF – Di isopropyl fluorophosphate. It is used in the estimation of the life span of blood platelets

Components Of Blood In Animals NEET Study Material

Clumping of RBC may take place when the blood of one person is mixed with the blood of another person if their Blood groups are not compatible due to antigen-antibody reaction. Blood group antigens occur in Red blood corpuscles while antibodies occur in plasma.

NEET Biology Blood Circulatory System Useful Information

Welker’s method IN employed for measuring a total amount of blood, plasma or RBC.

• 1 % of R R C. daily is destroyed in our body.
• Damaged or defective S A node can be corrected by implanting an artificial pacemaker.
• This instrument stimulates the heart artificially at regular intervals.

1. Vasodilator. A drug that opens up the narrow blood vessels.
2. Sphygmomanometer. An instrument used to measure blood pressure.
3. Cardioscope. An instrument fitted with a lens and light for examining the inside of the heart.
4. Angiography. X-ray of the blood vessels after injection of radio-opaque substance.
5. Coronary Angiography. When the contrast medium dye is injected into coronary arteries (arteries of the heart) and pictures are taken, it is known as coronary angiography.

• Clearing a blockage in the coronary artery by balloon surgery is called coronary angioplasty.

1. Angiogram. Film showing the arterial system after injecting radio-opaque material.
2. Haemodialysis. Removal of waste products from the blood kidney.
3. Arteriosclerosis different from atherosclerosis

Atherosclerosis. In this disease, a lumpy thickness develops on the inner walls of the arteries that prevents die dilation of vessels (arteries). The vessels become smaller in diameter and cannot fully expand.

1. In such cases, the platelet-derived growth factor (PDGF) is released which provides a rough surface to platelets. If such plaques are formed in a coronary artery, it may cause blockage of blood to the heart and result in heart attack or stroke.
2. However, in the case of arteriosclerosis, there is hardening and loss of elasticity of arteries. Sclerosis of the artery may cause pain in the chest, co RBC: WBC = 600: 1

The largest vein in the human body is the inferior vena cava, and the Largest Artery is the aorta.

• Smallest blood vessel in the body — blood capillary, co The giraffe’s blood pressure may be the highest.
• In human males, normally haemoglobin is 15.8 g/100 ml blood, and in human females 13.7 g/100 ml.
• Infants, at birth, have 23 g/100 ml. co ] gm. of haemoglobin when fully saturated combined with 1.34 ml oxygen.
• In Earthworm haemoglobin is dissolved in blood plasma and is not contained in blood cells, co Among all animals, the metabolic rate is the slowest in elephants.

Due to defective valves, blood keeps on leaking and the sound of a murmur is produced.

• Sympathetic nerves increase the rate of heartbeat. cO In fishes only deoxygenated blood flows through the heart,
• The sinoauricular node is composed of special muscle fibres, The spleen also controls some volume of blood, but blood volume is mainly controlled by veins, co In walls of ventricles, papillary muscles are present, and co Hepatic portal system is found in all chordates.
• At birth, the number of WBCs is more than the RBCs. co Frog has two pairs of lymph hearts, co Urea Transport. The blood in the hepatic vein contains the maximum amount of urea and the renal vein has the minimum amount.
• Several RBCs increase if one lives at a higher altitude because there is less oxygen on mountains, co Fish Without Haemoglobin.
• The Antarctic ice fish, Chaemocephalus, has transparent blood with little iron and no red corpuscles. Oxygen seems to be carried only by physical solution in the plasma,

Components Of Blood In Animals NEET Study Material

1. Blue Baby. A baby with a blue tinge to the skin due to insufficient oxygenation of the blood. It indicates a congenital heart or lung defect.
2. Insufficiency of Blood. The body does not contain enough blood to fully vascularise all the tissues. After a heavy meal, more blood flows to the gut and less to the brain. This makes one feel sleepy.
3. Slowest Blood Flow. Blood flow is slowest in the capillaries to allow enough time for the exchange of materials.
4. Ringer Solution. A solution containing chlorides of sodium. potassium and calcium that maintain the beating of an isolated frog’s heart is called Ringer’s solution.
5. Maturation of RBCs. It requires vitamin Bp and folic acid. Deficiency of these vitamins causes anaemia.
6. Spindle Cells. These occur in amphibian blood and help in blood clotting like the mammalian platelets, cs* With the removal of the spleen, the leucocyte count rises, cs* Excess calcium ions cause increased heartbeat.
7. The heart is wrapped around the rectum of a freshwater mussel. It means the rectum of freshwater mussel passes through the heart.
8. Keber’s organs’ pericardial glands discharge excretory products into the pericardial cavity in the freshwater mussel.
9. Crocodilian Heart. Among reptiles, crocodilians are exceptional in having a 4-chambered heart.

Invertebrate Hearts. Earthworm has 4 pairs of hearts. Cockroach has a 13-chambered, tubular heart, about as long as the body. In freshwater mussel, the rectum passes through the ventricle of the heart.

• Anophilin is the anticoagulant produced by blood.
• Daily about 30% of WBCs are destroyed.
• Heart Transplant. The world’s first human heart transplant was performed by Prof. Christian Bernard on December 21, 1967, in Cape Town, South Africa.
• India’s first human heart transplant was done by cardio surgeon P. Venugopal on August 3, 1994, at the All Indian Institute of Medical Sciences (AIIMS), Delhi.

NEET Biology Blood Circulatory System Questions from Competitive Examinations

Question 1. The pulmonary artery differs pulmonary vein in having :

1. No endothelium
2. Valves
3. Large lumen
4. Thick muscular walls.

Answer: 4. Thick muscular walls

Question 2. Match the names of the parts listed under column 1 with the names of the organs listed under column 2; Choose the answer which gives the correct combination of the alphabet:

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

Answer: 3. A — r, B — s, C — t, D — p

Question 3. The blood protein involved in blood coagulation is :

1. Fibrin
2. Thrombin
3. Prothrombin
4. Fibrinogen.

Answer: 4. Fibrinogen

Question 4. Blood vessel which brings oxygenated blood to the left atrium are:

1. Precaval vein
2. Postcaval vein
3. Pulmonary vein
4. Pulmonary artery.

Answer: 3. Pulmonary vein

Structure And Function Of The Heart NEET Exam Preparation

Question 5. A sample of blood shows clumping with antiserum A but not with antiserum B. The blood group would be :

1. O
2. A
3. B
4. AB.

Answer: 2. A

Question 6. A person with the AB blood group can receive blood from :

1. AB only
2. O only
3. Both A and B
4. All the above.

Answer: 4. All the above.

Question 7. Blood group B means the person :

1. Can form antibody for B
2. Cannot form antibody for B
3. Can receive the blood of AB group
4. Cannot receive blood group O.

Answer: 2. Cannot form antibody for B

Question 8. Which one carries oxygen?

1. Plasma
2. Lymph
3. Blood
4. Serum.

Answer: 3. Blood

Question 9. Collecting of WBCs at the site of injury occurs due to:

1. Phagocytosis
2. Hemolysis
3. Diapedesis
4. All the above.

Answer: 3. Diapedesis

Question 10. In Prawn, the heart pumps :

1. Deoxygenated blood
2. Oxygenated blood
3. Both (1) and (2)
4. Mixed blood.

Answer: 2. Oxygenated blood

Question 11. Blood circulation is open in :

1. human
2. cow
3. apes
4. cockroach.

Answer: 4. cockroach

Question 12. Heart sound which is longer is :

1. lubb
2. dup
3. both equal
4. sometimes (1) and sometimes (2).

Answer: 1. lubb

Question 13. Adrenaline directly affects:

1. S. A. node
2. P – cells of Langerhans
3. Dorsal root of the spinal cord
4. Epithelial cells of the stomach.

Answer: 1. S. A. node

Question 14. Continuous bleeding from an injured part of the body is due to a deficiency of :

1. Vitamin A
2. Vitamin B
3. Vitamin K
4. Vitamin E.

Answer: 3. Vitamin K

Question 15. Impulse of heartbeat originates from :

1. S. A. node
2. A. V. node
3. Vagus nerve
4. Cardiac nerve.

Answer: 1. S. A. node

Question 16. Organs which get only oxygenated blood are:

1. lungs
2. gills
3. liver
4. spleen.

Answer: 4. spleen.

Question 17. Bundle of His is a network of:

1. nerve fibres found throughout the heart
2. muscle fibres distributed throughout the heart walls
3. left auricle and left ventricle in higher vertebrates
4. nerve fibres distributed in ventricles.

Answer: 3. left auricle and left ventricle in higher vertebrates

Structure And Function Of The Heart NEET Exam Preparation

Question 18. Systemic heart refers to :

1. the two ventricles together in humans
2. the heart that contracts under stimulation from the nervous system
3. left auricle and left ventricle in higher vertebrates
4. entire heart in lower vertebrates.

Answer: 3. left auricle and left ventricle in higher vertebrates

Question 19. The diagram below shows how things get to and from the liver. They are labelled as A, B, C, D, E and F. Which one of the following labellings is the correct one?

1. A is the hepatic portal vein and E is the hepatic vein
2. C is the intestine and F is the hepatic portal vein
3. D is the hepatic portal vein and F is the hepatic vein
4. B is the pancreatic artery and E is the hepatic artery
5. D is the hepatic portal vein and E is the hepatic vein.

Answer: 3. D is the hepatic portal vein and F is the hepatic vein

Question 20. Choose the correct proportion with respect to the distribution of blood in the body of man :

1. 5% to heart muscles, 15% to brain, 25% to liver, 25% to kidney, 15% to bones, 15% to other organs.
2. 20% to heart muscles, 10% to brain,10% to liver, 25% to kidney, 10% to bones, 25% to other organs.
3. 10% to heart muscles, 10% to brain, 10% to liver, 40% to kidney, 15% to bones, 15% to other organs
4. 10% to heart muscles, 20% to brain, 20% to liver, 15% to kidney, 5% to bones, 35% to other organs
5. 15% to heart muscles, 20% to brain, 30% to liver, 40% to kidney, 5% to bones, 4% to other organs.

Answer: 3. 10% to heart muscles, 10% to brain, 10% to liver, 40% to kidney, 15% to bones, 15% to other organs

Question 21. The rate of the heartbeats and their conduction is represented in the pathway :

1. AVN-bundle of His network of Purkinje fibres
2. Network of Purkinje fibres – AVN – SAN-bundle of His
3. AVN – SAN – a bundle of this – Purkinje fibres
4. SAN – AVN – the bundle of this ^Purkinje fibres
5. SAN – AVN Purkinje fibres – a bundle of His.

Answer: 1. AVN-bundle of this network of Purkinje fibre

Question 22. Of the following the one which is an example of a buffer system in blood is :

1. haemoglobin and oxyhaemoglobin
2. oxygen and carbon dioxide
3. albumin and globulin
4. sodium bicarbonate and carbonic acid
5. oxygen and carbon monoxide.

Answer: 4. sodium bicarbonate and carbonic acid

Question 23. The chamber of the human heart, which has the thickest wall:

1. right atrium
2. left atrium
3. right ventricle
4. left ventricle.
5. None of these.

Answer: 3. right ventricle

Question 24. A person with blood group A has :

1. Antigen A and antibody b
2. Antigen B and antibody a
3. Both antibodies
4. No antibody and no antigen.

Answer: 1. Antigen A and antibody b

Question 25. The part of the antibody molecule which acts as a binding site for specific related antigens is :

1. Complete light chain
2. Complete heavy chain
3. Complete light and heavy chain
4. Variable parts of light and heavy chains.

Answer: 4. Variable parts of light and heavy chains

Question 26. The treatment of snake bite by antivenin is an example of :

1. Artificially acquired active immunity
2. Artificially acquired passive immunity
3. Naturally acquired passive immunity
4. Specific natural immunity.

Answer: 2. Artificially acquired passive immunity

Question 27. The percentage similarity in (3-chain of Hb in man and rhesus monkey is :

1. 2%
2. 4%
3. 8%
4. 40%.

Answer: 4. 40%.

Question 28. Serum is :

1. blood without fibrinogen
2. lymph without corpuscles
3. blood without corpuscles and fibrinogen
4. lymph.

Answer: 3. blood without corpuscles and fibrinogen

Question 29. The bundle of this is a group of :

1. nerve fibres
2. muscle fibres
3. connective tissue
4. ganglia.

Answer: 2. muscle fibres

Question 30. In which one of the following pair of terms both represent one and the same thing?

1. Mitral valve-bicuspid valve
2. Atrioventricular node—pacemaker
3. Leucocytes-lymphocytes
4. Plasma-serum.

Answer: 1. Mitral valve-bicuspid valve

Structure And Function Of The Heart NEET Exam Preparation

Question 31. The four-chambered heart is present in :

1. frog
2. crocodile
3. shark
4. lizard.

Answer: 2. crocodile

Question 32. The nucleus of a monocyte is :

1. two-lobed
2. kidney shaped
3. s-shaped
4. multi-lobed.

Answer: 2. kidney shaped

Question 33. You are required to draw blood from a patient and to keep it in a test tube for analysis of blood corpuscles and plasma. You are also provided with the following four types of test tubes. Which of these will you not use for the purpose?

1. test tube containing calcium bicarbonate
2. chilled test tube
3. test tube containing heparin
4. test tube containing sodium oxalate.

Answer: 3. test tube containing heparin

Question 34. Insulin and glucagon are transported to the target organ by :

1. lymph
2. blood
3. pancreatic duct
4. cystic duct.

Answer: 2. blood

Question 35. Which of the following is the correct pair?

1. Leucocytes—Lymphocytes
2. Haemophilia—Blood cancer
3. SA Node—Pacemaker
4. Malleus—Anvil.

Answer: 3. SA Node—Pacemaker

Question 36. An artificial pacemaker is implanted subcutaneously and connected to the heart in patients :

1. having 90% blockage of the three main coronary arteries
2. having a very high blood pressure
3. with irregularity in the heart rhythm
4. suffering from arteriosclerosis.

Answer: 3. with irregularity in the heart rhythm

Question 37. G—6-P dehydrogenase deficiency is associated with haemolysis of :

1. Lymphocytes
2. RBCs
3. Platelets
4. Leucocytes.

Answer: 2. RBCs

Blood Vessels Types And Functions NEET Biology

Question 38. Which of the following substances, if introduced into the bloodstream, would cause coagulation of blood at the site of its introduction?

1. Fibrinogen
2. Prothrombin
3. Heparin
4. Thromboplastin.

Answer: 4. Thromboplastin.

Question 39. Different factors play important roles in the coagulation of blood, some of the factors are listed in list-I and their nomenclatures are given in list-II. Find out the accurate matching

1. A: 2, B: 1, C: 4, D:3
2. A: 1, B: 2, C : 3, D: 4
3. A : 3, B: 4, C: 2, D: 1
4. A: 4, B: 4, C: 2, D: 1

Answer: 1.  A: 2, B: 1, C: 4, D:3

Question 40. Which of the following statements is wrong?

A. Leucocytes disintegrate in the spleen and liver.

B. RBC, WBC and blood platelets are produced by bone marrow.

C. Neutrophils bring about the destruction and detoxification of toxins of protein origin.

D. The important function of lymphocytes is to produce antibodies.

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

Answer: 3. (A) and (C) only

Question 41. What happens when the pacemaker is non-functional?

1. Only the auricles will contract rhythmically.
2. The cardiac muscle does not contract in a coordinated manner rhythmically.
3. Only ventricles will contract rhythmically.
4. Cardiac muscle will contract in a coordinated manner rhythmically.
5. Auricles and ventricles contract simultaneously.

Answer: 2. The cardiac muscle does not contract in a coordinated manner rhythmically.

Question 42. In sickle cell anaemia glutamic acid is replaced by

1. proline
2. alanine
3. serine
4. valine.

Answer: 4. valine.

Question 43. The process of formation of blood corpuscles is called.

1. Haempoeisis
2. Haemolysis
3. Haemozoin
4. None of these.

Answer: 1. Haempoeisis

Question 44.  Leech secretes which of the following anticoagulants?

1. Heparin
2. Hirudin
3. Serotonin
4. Histamine.

Answer: 2. Hirudin

Question 45. Mark the odd one :

1. Monocyte
2. Lymphocyte
3. Neutrophil
4. Erythrocyte.

Answer: 4. Erythrocyte.

Question 46. Find out the incorrect answer from the following?

1. veins are typically larger in diameter than arteries
2. because of their small size, capillaries contain blood that is moving more quickly than in other parts of the circulatory system
3. the walls of arteries are elastic, enabling them to stretch and shrink during changes in blood pressure
4. veins contain more blood than any other part of the circulatory system.

Answer: 2. because of their small size, capillaries contain blood that is moving more quickly than in other parts of the circulatory system

Question 47. How many times a red blood corpuscle will have to pass through the heart in its journey from the hepatic artery

1. Two times
2. Only once
3. Several times
4. Many times

Answer: 1. Two times

Question 48. ‘Heart to Heart ‘ is

1. SA node
2. AV node
3. Long bones
4. All of these

Answer: 1. SA node

Question 49. SA-node is located in :

1. Lower lateral wall of the right atrium
2. Upper lateral wall of the right atrium
3. Upper lateral wall of the left atrium
4. Lower lateral wall of left atrium

Answer: 2. Upper lateral wall of the right atrium

Question 50. Yellow bone marrow is found especially in the medullary cavity of:

1. Short bones
2. Spongy bones
3. Long bones
4. All of these.

Answer: 3. Long bones

Question 51. An insect bite may result in inflammation of that spot. This is triggered by the alarm chemicals such as :

1. Histamine and dopamine
2. Histamine and Kinins
3. Interferons and osponins
4. Interferons and histamine.

Answer: 2. Histamine and Kinins

Blood Vessels Types And Functions NEET Biology

Question 52. Which one of the following four secretions is matched with its source, target and nature of action?

Answer: 4.

Question 53. Closure of which of the following makes the louder sound of a heartbeat?

1. mitral valve
2. semilunar valve
3. auriculo-ventricular valve
4. tricuspid valve.

Answer: 3. auriculo-ventricular valve

Question 54. The diagram given here is the standard ECG of a normal person, The P-wave represents the following:

1. Initiation of the ventricular contraction
2. Beginning of the system
3. End of systole
4. Contraction of both the atria.

Answer: 4. Contraction of both the atria.

Question 55. In ECG, what does wave represent?

1. Diastole of auricles
2. Diastole of ventricles
3. Systole of ventricles
4. Diastole of auricles and ventricles.

Answer: 4. Diastole of auricles and ventricles

Question 56. Which leucocytes release heparin and histamines in the blood?

1. Eosinophil
2. Basophil
3. Neutrophil
4. Lymphocytes
5. Monocytes.

Answer: 2. Basophil

Question 57. Graveyard of blood is :

1. spleen
2. liver
3. kidney
4. thymus.

Answer: 1. spleen

Question 58. The given figure shows an angiogram of the coronary blood vessel. Which one of the following statements correctly describes, what is being done?

1. It is the coronary artery which has a cancerous growth that is being removed
2. It is the coronary artery which is blocked by a plaque and the same is being cracked
3. It is a coronary vein in which the defective valves are opened
4. It is a coronary vein blocked by a parasite (blood fluke) that is being removed.

Answer: 2. It is the coronary artery which is blocked by a plaque and the same is being cracked

Question 59. A drop of each of the following is placed separately on four slides. Which of them will not coagulate?

1. Blood serum
2. Sample from the thoracic duct of the lymphatic system
3. Whole blood from pulmonary vein
4. Blood plasma.

Answer: 4. Blood plasma.

Question 60. The valve situated between the left atrium and left ventricle is called :

1. mitral valve
2. bicuspid value
3. tricuspid valve
4. Eustachian valve.

Answer: 1. mitral valve

Blood Vessels Types And Functions NEET Biology

Question 61. The open circulatory system is present in

A. arthropods

B. annelids

C. chordates

D. molluscs

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

Answer: 5. A only

Question 62. In humans, blood passes from the postcard to the diastolic right atrium of the heart due to :

1. the pressure difference between the portocaval and atrium
2. stimulation of the sino-auricular node
3. pushing open the venous valves
4. suction pull.

Answer: 1. pressure difference between the portocaval and atrium

Question 63. Which one of the following statements is correct regarding blood pressure :

1. 130/90 mmHg is considered high and requires treatment
2. 100/55 mmHg is considered an ideal blood pressure
3. 105/50 mmHg makes one very active
4. 190/110 mmHg may harm vital organs like the brain and kidneys.

Answer: 4. 190/110 mmHg may harm vital organs like the brain and kidney.

Question 64. Arteries are best defined as the vessels which :

1. Supply oxygenated blood to the different organs
2. Carry blood away from the heart to different organs
3. Break up into capillaries which reunite to form a vein
4. Carry blood from one visceral organ to another visceral organ.

Answer: 2. Carry blood away from the heart to different organs

Question 65. ‘Bundle of His’ is a part of which one of the following organs in humans?

1. Brain
2. Heart
3. Kidney
4. Pancreas.

Answer: 2. Heart

Question 66. Which one of the following plasma proteins is involved in the coagulation of blood?

1. An albumin
2. Serum amylase
3. A globulin
4. Fibrinogen.

Answer: 4. Fibrinogen.

Question 67. The vem which is formed from the capillaries of an organ and terminates into capillaries in some intermediate organ before entering the heart is called :

1. Pulmonary vein
2. Coronary vein
3. Portal vein
4. Systemic vein

Answer: 3. Portal vein

Question 68. In a normal human, the cardiac output (stroke volume) is :

1. 47 ml
2. 20 ml
3. 5 litres
4. 3.3 litre.

Answer: 3. 5 litres

Question 69. Which one of the following is incorrect for ‘atherosclerosis’?

1. Constriction of the arterial lumen reduces blood flow.
2. Loss of dilation ability of the arterial wall and its rupture.
3. Cholesterol deposition at the inner wall of the artery.
4. Proliferation of the vascular muscles.

Answer: 2. Loss of dilation ability of the arterial wall and its rupture.

NEET Biology Blood Circulatory System in Animals Multiple Choice Questions

Question 1. The main difference in the circulation of blood and lymph is :

1. Lymphatics possess valves
2. movement of lymph is due to lymph heart
3. Lymph always moves towards the heart
4. Lymph moves unidirectionally in lymphatics.

Answer: 3. Lymph always moves towards the heart

Question 2. If you were asked to dissect an animal so as to reveal a valve, which of the following places would be good to try:

1. At the opening between the right atrium and the right ventricle
2. the fork where the pulmonary artery splits and one branch goes to each lung
3. the base of the aorta where it leaves the left ventricle
4. a vein in the arm.

Answer: 2. the fork where the pulmonary artery splits and one branch goes to each lung

Question 3. The introduction of a bacterial antigen into the body triggers a response specifically against the antigen by :

1. causing antibody molecules to assume a shape that permits them to bind and agglutinate the antibody
2. causing mutations in cells so that they produce antibodies to the antigen that caused the mutation
3. causing cells with the proper antibody to disintegrate and release the antibody
4. stimulating the reproduction of cells that make the antibody to that antigen.

Answer: 4. stimulating reproduction of cells that make the antibody to that antigen

Question 4. If most of its lymphocytes were drained out of an animal via the thoracic duct, the animal would not:

1. lose its ability to combat cancer and produce new lymphocytes
2. lose its ability to reject skin grafts
3. lose its ability to mount a secondary immune response
4. produce an increased number of red blood cells.

Answer: 4. produce an increased number of red blood cells.

Read and Learn More NEET Biology Multiple Choice Question and Answers

Body Fluids and Circulation NEET Question 5. Haemoglobin transports oxygen to the extent of:

1. 97% to 98%
2. 90 to 92%
3. 60 to 70%
4. 70 to 80%.

Answer: 1. 97% to 98%

Question 6. Which one of the following blood vessels has a thick muscular coat?

1. Veins
2. Capillaries
3. Arteries
4. Lymphatics.

Answer: 3. Arteries

Question 7. Which chamber of the human heart has the thickest muscular wall?

1. Right atrium
2. Left atrium
3. Right ventricle
4. Left ventricle.

Answer: 4. Left ventricle

Question 8. The blood flow is fast and with jerks in :

1. arteries
2. veins
3. veins and capillaries
4. None of the above.

Answer: 1. arteries

Question 9. Haemoglobin is found dissolved in the plasma of:

1. man
2. frog
3. birds
4. earthworm.

Answer: 4. earthworm.

Question 10. The correct sequence followed by the blood flowing through the heart of the frog is:

1. sinus venosus, right auricle, left auricle, truncus arteriosus
2. truncus arteriosus, ventricle, right auricle, left auricle
3. sinus venosus, left auricle, truncus arteriosus, right auricle
4. sinus venosus, right auricle, ventricle, truncus arteriosus.

Answer: 4. sinus venosus, right auricle, ventricle, truneus arteriosus.

Question 11. Which of the following is not a difference between the circulatory system of mammals and those of insects?

1. Substances must cross a vessel wall to reach the cells of mammals, but the blood of insects is in direct contact with their cells
2. Blood moves randomly in an insect but in a definite path in a mammal
3. Insects do not transport oxygen in their transport system, whereas mammals do
4. Mammals have much higher blood pressure than that of insects.

Answer: 2. Blood moves randomly in an insect, but in a definite path in a mammal

Question 12. A type of blood bank from which reserves of erythrocytes may be quickly mobilized when needed by the body is the :

1. liver
2. bone marrow
3. intestinal mesentery
4. spleen.

Answer: 4. spleen.

Body Fluids and Circulation NEET Question 13. The posterior pair of lymph hearts in frogs pump lymph into :

1. brachial vein
2. femoral vein
3. sciatic vein
4. external jugular vein.

Answer: 2. femoral vein

Question 14. Blood enters the heart because muscles of the :

1. atria contract
2. atria relax
3. ventricles contract
4. ventricles relax.

Answer: 2. atria relax

Question 15. The breakdown product of haemoglobin is :

1. biliverdin and bilirubin
2. globulin
3. biliverdin
4. calcium.

Answer: 1. biliverdin and bilirubin

Question 16. Blood from the kidneys of humans is returned by :

1. renal arterioles
2. renal vein and renal portal vein
3. renal veins
4. Bidder’s canal.

Answer: 3. Renal veins

Question 17. How many renal veins emerge out of frog and mammalian kidneys respectively?

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

Answer: 2. 4,1

Body Fluids and Circulation NEET Question 18. Select advantage of a double circulation ova u single circulation

1. In the double circulation, all the blood going to the tissue is oxygenated. whereas in single circulation it is not
2. In the double circulation. the blood can transport more types of substances
3. In double circulation, the blood is at higher pressure when it enters the body tissues and the blood travels around the body faster
4. In a double circulation, there are twice as many blood vessels servicing the body tissues.

Answer: 3. In double circulation, the blood is at higher pressure when it enters the body tissues and the blood travels around the body faster

Question 19. In the amphibian heart, the cavity present at the base of truncus arteriosus is called :

1. cavum pulmocutaneum
2. synagium
3. pylangium
4. cavum aorticum.

Answer: 3. pylangium

Question 20. The shoulder and forelimb are connected to the heart by :

1. subclavian artery
2. oesophageal artery
3. occipitovertebral
4. dorsal aorta.

Answer: 1. subclavian artery

Question 21. What will happen to the body of an adult man if the spleen is removed?

1. RBC production will be lowered
2. Antibody production will be less
3. Filtration of dead RBC will not be there
4. WBC production will be lowered.

Answer: 3. Filtration of dead RBC will not be there

Question 22. In persons suffering from sickle cell anaemia, erythrocytes become sickle-shaped when :

1. CO₂, concentration in the blood rises
2. 0₂ concentration in blood rises
3. 0₂concentration in the blood falls considerably
4. diet provides an insufficient amount of vitamin B₁₂

Answer: 3. 0₂concentration in the blood falls considerably

Body Fluids And Circulation MCQ Question 23. The greatest amount of oxygen will be lost from the blood while it is travelling through :

1. the capillaries around the alveoli
2. the left atrium of the heart
3. the arteries
4. the capillaries in the body.

Answer: 4. the capillaries in the body.

Question 24. The blood pressure is high in :

1. veins of the portal system
2. veins bringing the blood from the head
3. arteries
4. capillaries.

Answer: 3. arteries

Question 25. The exchange of materials between blood and interstitial fluid only at the :

1. capillaries
2. veins
3. arteries
4. arterioles.

Answer: 1. capillaries

Question 26. The rate of heartbeat per minute is highest in the case of:

1. elephant
2. whale
3. man
4. mouse.

Answer: 4. mouse

Question 27. Pick up the cells of bone marrow which give rise to all types of corpuscles of blood :

1. Plasmocytes
2. Megablasts
3. Osteoblasts
4. Reticular cells and haemocytoblasts.

Answer:  4. Reticular cells and haemocytoblasts.

Question 28. The proximal veins collect blood from :

1. head and hind limbs
2. lore limbs and hind limbs
3. head and forelimbs
4. trunk and forelimbs.

Answer: 3. head and forelimbs

Question 29. Thrombosis in which coronary artery is met most frequently in Ml (Myocardial infarction):

1. Right coronary artery
2. Left anterior descending artery
3. Left green flex coronary artery
4. Right circumflex coronary artery.

Answer: 1. Right coronary artery

Question 30. The portal system present in all the vertebrates is :

1. hepatic
2. renal
3. pulmonary
4. Both  1 and 3

Answer: 1. hepatic

Body Fluids And Circulation MCQ Question 31. S.A. node is a small flattened ellipsoid strip of muscle fibre measuring about:

1. 0.3 mm
2. 3 mm
3. 0.6 mm
4. 6 mm.

Answer: 1. 0.3 mm

Question 32. Haemolysis can occur in one of the following cases:

Answer: 4.

Question 33. The first heart sound created by the closure of the AV valve is loud. It lasts for:

1. 0.10 sec
2. 0.16 to 90
3. 0.5 sec
4. 0.5 to 20 sec.

Answer: 2. 0.16 to 90

Question 34. Patients in which atrial impulse suddenly falls to be transmitted to ventricles. Such a case is called :

1. Ventricular escape
2. Stokes
3. Adams syndrome
4. All of the above.

Answer: 4. All of the above.

Question 35. The free edges of the auriculo-ventricular valves are joined to the wall of the heart of fine collagen fibres called :

1. papillary
2. columnar camera
3. chordate tendineae
4. connecting fibres.

Answer: 3. chordate tendineae

Body Fluids And Circulation MCQ Question 36. The right auricle of the heart of a human is :

1. equal to the left
2. smaller than the left
3. larger than the left
4. None of the above.

Answer: 3. larger than the left

Question 37. The heart of fish is :

1. two chambered
2. single chambered
3. four chambered
4. three-chambered.

Answer: 1. two chambered

Question 38. Opening of pulmonary vein to left auricle is guarded by :

1. three semilunar valves
2. bicuspid valve
3. tricuspid valve
4. No valve.

Answer: 4. No valve.

Question 39. In a closed circulatory system, blood is completely closed within :

1. vessels
2. skeleton
3. sinuses
4. heart.

Answer: 1. vessels

Question 40.  The heart is enclosed in a double-walled thin bag called :

1. peritoneal
2. pericardial
3. pericardium
4. visceral peritoneum.

Answer: 3. pericardium

Question 41. The main function of pericardial fluid is :

1. lubrication
2. protective
3. protective and lubrication
4. antiseptic.

Answer: 3. protective and lubrication

Question 42. The heart is made of:

1. cardiac muscles
2. longitudinal muscles
3. horizontal muscles
4. connective muscles and horizontal muscles.

Answer: 1. cardiac muscles

Body Fluids And Circulation NEET Biology Question 43. The absolute refractory period of the heart is :

1. during contraction when the heart is in a non-responding period
2. during expansion
3. during negative charge
4. during positive charge.

Answer: 1. during a contraction when the heart is in a non-responding period

Question 44. The heart muscles work rhythmically always by :

1. external stimuli
2. their own property
3. action of liver
4. action of hormones.

Answer: 2. their own property

Question 45. In the mammalian heart, there is very swift conduction of stimulation all over the heart because of:

1. bundle of His and Purkinje fibres
2. pericardial fluid
3. peritoneum
4. proteins in the heart.

Answer: 1. bundle of His and Purkinje fibres

Question 46. Heartbeats are affected by :

1. vagus nerve which increases the heartbeats
2. vagus nerve which reduces the heartbeats
3. central nervous system
4. digestive system.

Answer: 2. vagus nerve which reduces the heartbeats

Question 47. Heartbeats are accelerated by the :

1. cranial nerve
2. stomach peristalsis
3. number of red blood cells
4. sympathetic nerves.

Answer: 4. sympathetic nerves.

Body Fluids And Circulation NEET Biology Question 48. Ringer’s solution contains :

1. Iodine and salt
2. Acetic acid and wax
3. Sodium and potassium ions
4. Water and acid fuschin.

Answer: 3. Sodium and potassium ions

Question 49. The heartbeat is initiated by a special heart tissue embodied in the wall of the right wall of the right auricle. This is called :

1. sinu-auricular node
2. sinu-ventricular node
3. auriculo-vcntricular node
4. Rt. ventricle and Lt. ventricle nodes.

Answer: 1. sinu-auricular node

Question 50. The common name of the sinus-auricular node is:

1. Pacesetter
2. Pacemaker
3. Blood regulator
4. Blood colloid.

Answer: 2. Pacemaker

Question 51. As in other cells, heart muscle fibres also carry an electric charge. This is:

1. positive on the outer surface and negative on the inner
2. negative on the outer surface and positive on the inner
3. positive on both inner and outer surfaces
4. negative on both inner and outer surfaces.

Answer: 1. positive on the outer surface and negative on the inner

Question 52. The opening of auricles into the ventricle in frogs is guarded by :

1. a single semilunar valve
2. three semilunar valves
3. auriculo-ventricular valve
4. a sphincter.

Answer: 3. auriculo-ventricular valve

Body Fluids And Circulation NEET Biology Question 53. During the coagulation of blood, vitamin K helps in the :

1. conversion of prothrombin to thrombin
2. formation of prothrombin
3. conversion of fibrinogen to fibrin
4. formation of thromboplastin.

Answer: 2. formation of prothrombin

Question 54. Oxygenated blood enters the heart in the :

1. right ventricle
2. right auricle
3. left ventricle
4. left auricle.

Answer: 4. left auricle.

Question 55. The sciatic vein collects blood and pours it in :

1. pelvic vein
2. renal portal vein
3. renal vein
4. anterior abdominal vein.

Answer: 2. renal portal vein

Question 56. Blood from the lungs of humans is carried by :

1. azygos vein
2. anterior abdominal
3. pulmonary vein
4. cutaneous vein.

Answer: 3. Pulmonary vein

Question 57. When a normal frog is injected with the physiological concentration of adrenaline, the heartbeat shows :

1. Initiation of heartbeat
2. Conduction of heartbeat
3. Increased rate of heartbeat
4. Release of acetylcholine.

Answer: 3. Increased rate of heartbeat

Question 58. The circulation of blood was first discovered by :

1. Lamarck
2. William Harvey
3. Darwin
4. Hugo de Vries.

Answer: 2. William Harvey

Question 59. The opening of the upper chamber of the heart into the lower chamber is known as :

1. sinu-auricular aperture
2. auriculo-ventricular aperture
3. atrioventricular septum
4. atrioventricular node.

Answer: 2. auriculo-ventricular aperture

Question 60. The blood leaving the lungs is richer than the blood entering the lungs in :

1. the number of RBC per ml. of blood
2. the amount of oxygen per ml. of blood
3. the amount of haemoglobin per ml. of blood
4. the amount of nutrients per ml. of blood.

Answer: 2. the amount of oxygen per ml. of blood

Question 61. The artery which carries deoxygenated blood is known as :

1. pulmonary artery
2. aorta
3. coronary artery
4. pulmocutaneous.

Answer: 1. pulmonary artery

Body Fluids And Circulation NEET Biology Question 62. When the valves prevent the backflow of the blood, the circulation stent is called as

1. bilateral
2. lateral
3. closed
4. Open

Answer: 2. lateral

Question 63. The intravenous injection of blood plasma or serum with the object of restoring the blood volume is known its:

1. transplantation
2. Trasfusion
3. transcription
4. vaccination.

Answer: 2. Transfusion

Question 64. Which of the following statements is true for arteries?

1. Arteries are thin-walled and blood in them is under low pressure
2. Arteries are thin-walled and blood in them is under high pressure
3. Arteries are thick-walled and blood in them is under low pressure
4. Arteries are thick-walled and blood in them is under high pressure.

Answer: 4. Arteries are thick-walled and blood in them is under high pressure.

Body Fluids and Circulation NEET  Question 65. Perfusion of the heart of a frog with acetylcholine will cause :

1. decreased heartbeat
2. systolic arrest
3. diastolic arrest
4. extra systole.

Answer: 1. decreased heartbeat

Question 66. The connection between arteries and veins is through :

1. Arteriole
2. venule
3. capillaries
4. None of the above.

Answer: 3. capillaries

Question 67. The blood which after circulation comes from the liver to the heart has :

1. increased CO₂, content
2. increased bile content
3. increased blood content
4. increased 0₂ content.

Answer: 1. increased CO₂ content

Question 68. The innermost coat of the wall of the artery is called :

1. tunica extrema
2. tunica media
3. arnica adventitia
4. endothelium.

Answer: 4. endothelium

Question 69. The wall of the vein is :

1. thin
2. thick
3. equal to that of the artery
4. None of the above.

Answer: 1. thin

Question 70. Tunica media of blood vessels is formed of:

1. endothelium
2. connective tissue
3. unstriped muscle fibres
4. Both 1 and 3.

Answer: 3. Unstriped muscle fibres

Body Fluids and Circulation NEET  Question 71. An adult human with average health has systolic and diastolic pressures as :

1. 80 mm Hg and 80 mm Hg
2. 70 mm Hg and 120 mm Hg
3. 120 mm Hg and 80 mm Hg
4. 50 mm Hg and 80 mm Hg.

Answer: 3. 120 mm Hg and 80 mm Hg

Question 72. With respect to the ABO group, there are found major blood types because this blood group is determined by :

1. three alleles, all of which are co-dominant
2. three alleles, all of which are recessive
3. three alleles, of which two are recessive and the third is dominant
4. three alleles, of which two are codominant and the third is recessive.

Answer: 4. three alleles, of which two are codominant and the third is recessive

Question 73. Heartbeats are affected by.

1. Carbon dioxide
2. Oxygen
3. Vagus nerve
4. All of these.

Answer: 3. Vagus nerve

Question 74. Which of the following Is the cancerous state of blood?

1. Chloremia
2. leukaemia
3. Uremia
4. Proteinemia

Answer: 2. leukaemia

Question 75. Oxygenated blood Is found lit :

1. Pulmonary veins
2. Pulmonary arteries
3. Right atrium
4. Right ventricle,

Answer: 1. Pulmonniy veins

Question 76. Heartbeat originates from :

1. Pacemaker
2. Cardiac muscles
3. Left atrium
4. Right ventricle.

Answer: 1. Pacemaker

Question 77. In vertebrate blood the carrier of oxygen to the tissues or respiratory pigment is.

1. Plasma
2. Lymphocytes
3. Leucocytes
4. Haemoglobin.

Answer: 4. Haemoglobin

Question 78. Who discovered the Rh factor?

1. Huxley
2. Landsteincr
3. Landsteiner and Weiner
4. Weiner.

Answer: 3. Landsteiner and Weiner

Body Fluids and Circulation NEET  Question 79. The gene for the main factor for the clotting of blood is present.

1. X chromosome
2. Y chromosome
3. Both the X and Y chromosome
4. Autosomes.

Answer: 1. X chromosome

Question 80. Which of the following is not a granulocyte?

1. Lymphocyte
2. Eosinophil
3. Basophil
4. Neutrophil.

Answer: 1. Lymphocyte

Question 81. The life span of human W.B.C. is approximately :

1. 48 hours
2. 24 hours
3. 120 days
4. 100 hours.

Answer: 1. 48 hours

Question 82. Megakaryocytes give rise to :

1. Erythrocytes
2. Granulocytes
3. Agranulocytes
4. Thrombocytes.

Answer: 4. Thrombocytes

Question 83. Which of the following statements is not correct for sickle cell anaemia?

1. The sixth amino acid (from the NH₂ terminus) of the beta chain is glutamic acid
2. Erythrocytes elongate and form sickle-shaped cells
3. Individuals homozygous for the haemoglobin S allele are Hb B /Hb B
4. The beta chain of haemoglobin S contains valine.

Answer: 1. Sixth amino acid (from the NH₂ terminus) of the beta chain is glutamic acid

Question 84. The mitral valve is present between :

1. Left auricle and left ventricle
2. Right auricle and right ventricle
3. The right ventricle and aortic arch
4. Left ventricle and pulmonary arch.

Answer: 1. Left auricle and left ventricle

Body Fluids and Circulation NEET  Question 85. Which of the following factors is known as the ‘Christmas factor’ :

1. Factor VIII
2. Factor XII
3. Factor IV
4. Factor IX.

Answer: 4. Factor IX

Question 86. Nucleated RBCs found in :

1. Man
2. Rat
3. Frog
4. Rabbit

Answer: 3. Frog

Question 87. In rabbits cardiac sphincter is found in :

1. Heart, on left dorsal aorta.
2. Heart, on right auricle and ventricle
3. Between the oesophagus and stomach
4. Between stomach and duodenum.

Answer: 3. Between the oesophagus and stomach

Question 88. The tendons connecting papillary muscles and heart valves are called :

1. Muscle column
2. Heart tendon
3. Chordae tendineae
4. Pedirate muscles.

Answer: 3. Chordae tendineae

Body Fluids And Circulation MCQ  Question 89. QRS is related to:

1. Ventricular contraction
2. Ventricular relaxation
3. Auricular contraction
4. Depolarisation.

Answer: 1. Ventricular contraction

Question 90. Sinus venous is absent in :

1. Mammals
2. Frog
3. Reptiles
4. Amphibians.

Answer: 1. Mammals

Question 91. The pacemaker of the heart is made up of :

1. Smooth muscles
2. Cardiac muscles
3. Nerve tissue
4. Triage

Answer: 2. Cardiac muscles

Question 92. The pacemaker of the heart is introduced for :

1. Regulation of heartbeat
2. Conduction of heartbeat
3. To stop the heartbeat
4. Pacemaker is absent.

Answer: 1. Regulation of heartbeat

Body Fluids And Circulation MCQ  Question 93. Vertebrate’s heart originates from :

1. A splanchnic layer of mesoderm facing the anterior intestinal part
2. Ectoderm lying over the forebrain
3. The inner lining of the neural tube
4. Primitive streak

Answer: 1. Splanchnic layer of mesoderm facing the anterior intestinal part

Question 94. The rate of heartbeat is controlled by :

1. Vagus only
2. Sympathetic nervous system
3. Both the vagus and sympathetic nervous system
4. Hormones only.

Answer: 3. Both the vagus and sympathetic nervous system

Question 95. O₂ carrying capacity of blood is :

1. 1200ml./100 ml of blood
2. 1200ml./100 ml of blood
3. l20 ml 7100 ml of blood
4. 500ml./100 ml of blood.

Answer: 3. l20 ml 7100 ml of blood

Question 96. At high altitudes, some changes take place in blood. This change is :

1. Increase in leucocyte count
2. Increase in red blood corpuscles count
3. Decrease in red blood cell count
4. Increase in blood platelets.

Answer: 2. Increase in red blood corpuscles count

Question 97. The chambered heart are found in :

1. Squamata
2. Lacertilian
3. Crocodilia
4. DiOphidia.

Answer: 3. Crocodilia

Body Fluids And Circulation MCQ  Question 98. Normal WBC count is 5000 to 10,000 cub/mm of blood. When the number of WBCs falls below normal level this is called leucopenia. It occurs due to :

1. Tuberculosis
2. Typhoid fever
3. Allergies
4. Blood cancer.

Answer: 1. Tuberculosis

Question 99. The pulse rate is the result of:

1. Atrial systole
2. Atrial diastole
3. Ventricular systole
4. Ventricular diastole.

Answer: 3. Ventricular systole

Question 100. The venous system of a frog differs from rabbit in having :

1. Hepatic portal system
2. Renal portal system
3. Both hepatic and renal portal systems
4. Veins

Answer: 2. Renal portal system

Question 101. The heart is innervated by :

1. Vagus
2. Facial
3. Trigeminal
4. Glossopharyngeal

Answer: 1. Vagus

Question 102. The right atrium of a man’s heart receives blood from

1. Sinus venous
2. Pulmonary veins
3. Inferior vena cava
4. Superior and Inferior vena cava

Answer: 4. Superior and Inferior vena cava

Question 103. During diastole

1. Blood leaves the heart
2. Blood enters the heart
3. Blood leaves the ventricle
4. Blood enters the lungs.

Answer: 2. Blood enters the heart

Body Fluids And Circulation MCQ  Question 104. The bicuspid valve allows blood from :

1. Right auricle lo left ventricle
2. Right auricle lo right ventricle
3. Left auricle lo left ventricle
4. Postcaval to heart.

Answer: 3. Left auricle lo left ventricle

Question 105. Blood pressure is defined as :

1. The force with which blood pushes against the wall of the blood vessels
2. The force with which blood is pushed to the legs
3. The force with which blood comes out of the atrium.
4. The force with which blood comes out of the ventricle.

Answer: 1. The force with which blood pushes against the wall of the blood vessels

Question 106. Blood supply to the kidney is :

1. 25%
2. 20%
3. 90%
4. 50%.

Answer: 1. 25%

Question 107. Match the column :

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

Answer: 3. A — t, B — r, C — p, D — q

Question 108. During high blood pressure, regulation of heartbeat and circulation is controlled by :

1. Vasodilator and vasoconstrictor centres.
2. Cardio-stimulatory and vasoconstrictor centres
3. Cardio-inhibitory and vasoconstrictor centres
4. Cardio-inhibitory and vasodilator centres.

Answer: 2. Cardio-stimulatory and vasoconstrictor centres

Question 109. What is true about veins?

1. All veins carry deoxygenated blood
2. All veins carry oxygenated blood
3. They carry blood from organs towards the heart
4. They carry blood from the heart towards the organs.

Answer: 3. They carry blood from organs towards the heart

Question 110. Blood pressure is measured by :

1. Sphygmomanometer
2. Phonocardiogrant
3. Electrocardiogram
4. Stethoscope.

Answer: 1. Sphygmomanometer

Body Fluids And Circulation MCQ  Question 111. In which of the capillary system is present

1. Arthropods
2. Cephalopods
3. Tunicates
4. Hemicordates

Answer: 2. Cephalopods

Question 112. The respiratory pigment is dissolved  in the plasma of blood in the case of:

1. Crustaceans
2. Cyclostomes
3. cnidarians
4. chondricthythes.

Answer: 1. Crustaceans

Question 113. The heart of the cockroach is 13-chambered, Each chamber bears a pair of aperture guarded by valves. The apertures are :

1. Sinn-auricular aperture
2. Aurieuloventrieular aperture
3. Ostia
4. Osculum.

Answer: 3. Ostia

Question 114. Which of the following is involved in maintaining the pH of the blood by buffering action?

1. Na+, K+ and Cl+₂
2. Ca₄. Mg₄₄ and HC0₃
3. HP0₄-2 and P0₄-3
4. All of the above.

Answer: 3. HP0₄-2 and P0₄-3

Question 115. Erythrocytes do not contain :

1. Haemoglobin
2. Carbonic anhydrase
3. Cl-
4. None of the above.

Answer: 4. None of the above

Question 116. Neutrophils are responsible for protection against infection. They constitute how much % age of total leucocyte count:

1. 3 %
2. 0.5 % to 1
3. 62 %
4. 30 %.

Answer: 3. 62 %

Question 117. Monocytes have kidney-shaped nuclei and constitute 5-6 per cent of total WBC. The diameter of a monocyte is about:

1. 10 -18 mm
2. 10 – 10 mm
3. 2 – 4 mm
4. 12 – 15 mm.

Answer: 1. 10 -18 mm

Question 118. If there is a complete mixing of oxygenated and deoxygenated blood in the heart, then :

1. blood to the lungs would be low in oxygen and the tissues would receive blood rich in oxygen
2. blood to the lungs would be rich in oxygen and the tissues would receive blood which is low in oxygen
3. lungs and tissues would receive blood with the same amounts of oxygen
4. tissues would receive completely oxygenated blood and lungs would receive complete
   deoxygenated blood.

Answer: 3. lungs and tissues would receive blood with the same amounts of oxygen

Body Fluids And Circulation NEET Biology Question 119. QRS in ECG is related to :

1. Atrial contraction
2. Ventricular contraction
3. Ventricular relaxation
4. Atrial relaxation.

Answer: 2. Ventricular contraction

Question 120. The most important centre for the formation of lymph is:

1. bone marrow
2. liver
3. pancreas
4. gastric glands.

Answer: 2. liver

Question 121. Which one of the following statements is correct?

1. The greater the 0₂ affinity of haemoglobin, the lower the extraction rate of oxygen
2. Terrestrial amphibians require much lower environmental oxygen pressure than aquatic forms
3. Aquatic reptile lorry require twice the environmental oxygen pressure than the terrestrial forms
4. The oxygen extraction power of haemoglobin is inversely proportional to the atmospheric pressure.

Answer: 4. The oxygen extraction power of haemoglobin is inversely proportional to the atmospheric pressure.

Question 122. Mammals native to high altitudes have haemoglobins of greater oxygen affinity than low-altitude forms because :

1. they need more oxygen than their, low altitude counterparts
2. the haemoglobin allows the extraction of oxygen from environments poor in oxygen (high altitudes) relative to low altitudes
3. they have less number of erythrocytes than their counterparts on low altitudes and increased oxygen affinity balances the reduced percentage of erythrocytes
4. the statement is not correct.

Answer: 2. the haemoglobin allows extraction of oxygen from environments poor in oxygen (high altitudes) relative to low altitudes

Question 123. The innermost layer of blood capillaries is made up of:

1. endothelial cells
2. haemocytes
3. elastic membrane
4. 1 and 3.

Answer: 4. 1 and 3

Body Fluids And Circulation NEET Biology Question 124. The cords of Billorth are blood spaces which are found in :

1. liver
2. tonsils
3. kidneys
4. spleen.

Answer: 4. spleen.

Question 125. Match the different leucocytes given under Column1 with their functions given under Column 2; choose the answer that gives the correct combination of alphabets of two columns

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

Answer: 2. A = r, B = p, C = q, D = t

Question 126. Which vitamin helps in blood coagulation?

1. Vitamin K
2. Vitamin C
3. Vitamin A
4. Vitamin D

Answer: 1. Vitamin K

Question 127. Which one of the following is mainly responsible for the second heart sound?

1. Closure of atrioventricular valves.
2. Opening of atrioventricular valves.
3. Closure of semilunar valves.
4. Thrust of blood on ventricular wall during atria contraction.

Answer: 3. Closure of semilunar valves

NEET Biology Plant Kingdom An Introduction And Algae Characteristics Of Kingdom Plantae

Kingdom Plantae. This kingdom includes multicellular producers. The characteristics are:

1. Complex eukaryotic, multicellular plants adapted for photosynthesis.
2. The plant cells are rigid because of cellulose cell walls.
3. Mostly the cells are rigid and cannot contract and relax like animal cells do. Plant cells are immobile and do not exhibit the phenomenon of locomotion.
4. Plants synthesize all their organic constituents from water, C02 and inorganic forms of essential elements using light energy trapped by chlorophyll and accessory pigments. The photosynthetic region contains plastids in their cells.
5. Reproduction by both asexual and sexual methods. Gametic meiosis during sexual reproduction.
6. Life history shows the alternation of generations. Sporophyte generation produces spores which develop into gametophytic plants and produce gametes.
7. Growth is generally indefinite.
8. Structural differentiation occurs except in some lower forms.
9. Higher forms have well-defined growing points with meristems.
10. The food reserve is starch and fat.

Read and Learn More NEET Biology Notes

Plant Kingdom NEET Notes

Classification Of Plants

His kingdom includes green algae, brown algae, red algae, bryophytes, pteridophytes, gymnosperms and angiosperms. The important characteristics are plastids in their cells.

Some forms have an absorptive mode of nutrition, still other forms may get modified to have a symbiotic relationship.

NEET Biology Plant Kingdom System Of Classification Of Phanerogams By Bentham And Hooker (1862-1883)

Polypetalae- Petals separate

Series Thalamiflorae-Hypogynous, stamens and pistils many, indefinite, mostly free distinct sepals free from the ovary.

Order 1. Ranales

Families-

• Ranunculaceae,
• Dilleniaceae,
• Calycanthaceae,
• Magnoliaceae,
• Anonaceae,
• Menispermaceae,
• Berberidaceae,
• Nymphaeaceae.

Order 2. Parietales

Families-

• Sarraceniaceae,
• Papaveraceae,
• Cruciferae,
• Capparidaceae,
• Resedaceae,
• Cistineae,
• Violaceae,
• Canellaceae,
• Bixineae.

Plant Kingdom NEET Study Material

Order 3. Polygalineae

Families-

• Pittosporeae,
• Tremandreae,
• Polygaleae,
• Vochysiaceae.

Order 4. Caryophyllineae

Families-

• Frankeniaceae,
• Caryophyllaceae,
• Portulcaceae,
• Tamariscineae.

Order 5. Guttiferales

Families-

• Elatineae,
• Hypericineae,
• Guttifereae,
• Temstroemiaceae,
• Dipterocarpeae,
• Chlaenaceae.

Order 6. Malvales

Families-

• Malvaceae,
• Sterculiaceae,
• Tiliaceae.

Series Disciflorac. Hypogynous, calyx consists of free or united sepals which are usually free from the ovary.

A prominent cushion-shaped disc is present below the ovary. Ovary-free or embedded in the receptacular disc. Stamens are usually definite in number.

Order 7. Geraniales

Families-

• Lineae,
• Humiriaceae,
• Malpighiaceae,
• Zygophylleae,
• Geraniaceae,
• Rutaceae,
• Simarubeae,
• Ochnaceae,
• Burseraceae,
• Meliaceae,
• Chailletiaceae.

Order 8. Olacales

Families-

• Olacineae,
• Ilicineae,
• Cyrilleae.

Order 9. Celastralcs

Families-

• Ccllastrineae,
• Stackhousieae
• Rhamneae,
• Ampelideae.

Order 10. Sapindales

Families-

• Sapindaccae,
• Sabiaccac,
• Anacardiaceae,
• Coriarieae,
• Moringcae

Plant Kingdom NEET Question Bank

Series 3. Multivulatae Terrestres

Families-

• Nepenthaceae,
• Cytinaceae,
• Anstolo-chieae.

Series 4. Micrembryea

Families-

• Piperaceae,
• Chloranthaceae,
• Myristi-cease,
• Moniaceae.

Series 5. Daphnales

Families-

• Laurineae,
• Proteaceae,
• Thymelaceae,
• Penaeaceae,
• Eleagnaceae.

Series 6. Achlamydosporeae

Families-

• Loranthaceae,
• Santalaceae,
• Balanophoreae.

Series 7. Unisexual

Families-

• Euphorbiaceae,
• Blanopseae,
• Urticaceae,
• Plantanaceae.
• Leitnerieae,
• Juglandeae,
• Myricaceae,
• Casuarineae,
• Cupuliferae.

Series 8. Ordines anomali (Anomalous Families)

Families-

• Salicaceae,
• Lacistemaceae,
• Empetraceae,
• Ceratophylleae.

Gymnospermae:

Families-

• Gnetaceae,
• Coniferae,
• Cycadaceae.
• Monocotyledones:

Series 1. Microspermae: Ovary superior tricarpellary. Seeds are very minute and many. Inner perianth leaves petaloid.

Families-

• Hydrocharidae,
• Burmanniaceae.
• Orchideae.

Series 2. Epigynae: Ovary inferior.

Families-

• Scitamineae,
• Bromellaceae,
• Heamodoraceae.
• Irideae.
• Amaryllidae,
• Taccaceae,
• Diosco-reaceae.

Series 3. Coronarieae: Ovary superior, albuminous.

Families-

• Roxburghiaceae,
• Liliaceae,
• Pontederiaceae,
• Philydraceae,
• Xyrideae,
• Mayacaceae,
• Commelinaceae,
• Rapateaceae.

Series 4. Calycineae: Ovary superior; albumen copious; perianth inconspicuous, sepaloid, stiff or herbaceous.

Families-

• Flagellarieae,
• Juncaceae,
• Palmae.

Series 5. Nudiflorae: Ovary superior perianth absent or reduced to scales.

Families-

• Pandaneae,
• Cyclanthaceae.
• Typhaccae.
• Aroideae,
• Lemnaceae.

Series 6. Apocarpae: Ovary superior, carpels separate or single.

Families-

• Triurideae,
• Alismaceae,
• Najadaceae.

Series 7. Glumaceae: Ovary single-celled, single ovule. Flowers in spikelets or heads. Perianth scale-like

Plant Kingdom NEET Question Bank

NEET Biology Plant Kingdom Stelar System

A stele is a column containing vascular tissues which is surrounded by a pericycle and separated from ground tissue by endodermis. There may be single stele (monostelic), two steles (distelic) or many steles (polystelic). Steles are of many types.

1. Protostele. It is the most primitive stele which consists of a solid core of xylem surrounded by phloem and pericycle. Pith is absent. Haplostele. It is a typical protostele which may be rounded or flattened, for Example, Selaginella chrysocaulos.

• Actinostele. The xylem is stellate (with rays of protoxylem) and surrounded by phloem, Example Lycopodium serratum.
• Plectostele. The xylem is broken into plates immersed in the phloem, for Example, Lycopodium volubile.
• Mixed Protestele. Irregular groups of xylem embedded in phloem, Example Lycopodium cemuum.
• Protostele with Mixed Pith. The central part has parenchyma and xylem. It is surrounded by phloem, for Example, Gleicheinea dichotoma.

2. Siphonostele. It is a medullated protostele or protostele with a central non-vascular pith. Leaf gaps are absent. Siphonstele is of two types:

Ectophloic Siphonostele. The central pith is surrounded successively by the xylem, phloem, pericycle and endodermis.

Amphiphloic Siphonostele. There is a central pith. The xylem is surrounded on either side by phloem, pericycle and endodermis.

Solenostele. It is similar to siphonostele but has scattered leaf gaps so that in T.S. it often appears horse-shoe shaped.

Dictyostele. It is a hollow stele with overlapping leaf gaps so that the vascular cylinder appears as a hollow network of strands called meristeles. In T.S., the dictyostele appears as a ring of meristeles, each with a protostelic structure, for example, Dryopteris.

Polycyclic Stele. A stele has two or more concentric cylinders, for Example, Matoniapectinata.

Eustele. It is a polyfascicular siphonostele which consists of several parallel vascular bundles separated by medullary rays or perforations, for Example, gymnosperms, and dicots.

Atactostele. Several vascular bundles (conjoint and collateral) occur scattered in ground tissue, for example, monocots.

Radial Bundles. Xylem and phloem occur in separate alternate bundles Example roots.

NEET Biology Plant Kingdom Algae Characteristics Of Algae

• The study of algae is called phycology and scientists working on algae are called Phycologists or Algologist.
• The algae (Linnaeus) is a collective term for all those chlorophyll-containing organisms which are thalloid, pond scums, stoneworts, and seaweeds. The thallus is non-vascular and thus has no elements for the transport of fluids.
• Algae occupy a wide range of habitats as follows :
• Terrestrial habitats. Some algae grow well in moist and well-aerated soils. They are called edaphophytes Example Fritschiella (grows on acidic soil), Vaucheria, etc.
• Aquatic habitats. Most algae grow in freshwater (waters of low salinity) or in marine water (saline water of sea having a solute concentration of 33-40 parts per thousand).

They are grouped under:

• Phytoplanktons. The aquatic algae float freely on the surface of the water body and move on the mercy of water currents (For example Chlorella, Chlamydomonas, Volvox, Cosmarium, etc.). Sometimes the colour of water changes due to the colour of plankton, called water bloom.
• The Red Sea is due to the luxuriant growth of blue-green algae-Trichodesmium erythronium over the surface of seawater.
• Benthos. The algae growing attached to the bottom of a water body are called benthos. The forms which grow attached to bottom soil or mud are called epipelagic and those which grow attached to rocks and stones are called epilithic.

Peculiar habitats

Cryophytes. Such algae grow in the polar regions on ice and snow at low temperatures Example Chlamydomonas nivalis, Ulothrixflaccida, etc. These algae produce specific colours.

For example snow (formed by Chlamydomonas nivalis), Black snow (formed by Raphidonema), Purple snow (formed by Ancylonema nordenskioldii), Blue snow (formed by Dactylococcopsis caucasica), Yellow snow (formed by Chlamydomonas flavivirus), Red-snow ball (formed by Haematococcus sp.), etc.

Thermophytes. Such algae grow in very hot water (near hot springs) with a temperature ranging between 70° to 80°C.

Epiphytes. Algae growing on the surface of other plant parts are called epiphytes ) Examples are Oedogonium, Ulothrix, Cladophora, etc.

Epizoophytes. Algae growing on the bodies of animals are called epizoophytes Example Cladophora grows on snails, and Cyanoderma (red alga) and Trichophilus (green alga) grow on the scales of sloth.

Endophytes. Algae growing within the tissue of other plants are called endophytes.

Endozoophytes. Algae grow inside the body of animals Example Chlorella grows within the tissue of Hydra and sponges.

Symbiotic algae. Some algae grow in symbiotic associations Example Lichens.

Parasitic algae. Some algae grow as parasites on other plants Example CephaleuroS Viruses (Causes Red Rust Of Tea)

Plant Kingdom NEET Mcqs

The algae exhibit great diversity in a range of thallus.

• Algae vary in size from small microscopic to large giant kelps. They have a wide range of thallus organisations. Examples of the various forms are given below:
  • Unicellular motile forms- Chlamydomonas.
  • Unicellular non-motile forms- Chlorella.
  • Palmelloid forms- Palmella, Tetraspora, etc.
  • Dendroid (tree-like) forms- Prasinocladus.
  • Non-motile colonial forms- Hydrodictyon.
  • Motile colonial forms- Volvox.
  • Unbranchedfilamentousforms- Spirogyra, Ulothrix, Oedogonium, etc.
  • Branched filamentous forms- Cladophora.
  • Heterotrichous forms- Fritschiella, Ectocarpus, etc.
  • Siphonaceous forms- Vaucheria.
  • Pseudoparenchymatous forms- Nemalion.
  • Parenchymatous forms- Ulva, Laminaria, etc.
• The cells constituting the thalli of algae are eukaryotic.
• The structure is of various kinds flagellate unicellular (Example Chlamydomonas), nonflagellate unicellular, (Example Chlorella), flagellate colony (ExampleGonium, Volvox), nonflagellate colony (Example Hydrodictyon), coenocytic (Example Caulerpa), filamentous (Example Ulothrix), parenchymatous (Example Ulva), etc.
• A colony with a fixed number of cells is called coenobium, for Example, Volvox.
• Unicellular Acetabularia (Umbrella Plant) has a holdfast (with a nucleus), a stalk and an umbrella-like cap. Caulerpa is differentiated into rhizome-like prostrate parts with rhizoids for fixation and leaf-like vertical assimilators.
• Oedogonium (an unbranched filamentous alga) contains caps on the cells which undergo division (hence cap cells).
• The pigments are chlorophylls, carotenoids, phycobilins or biloproteins and nutrition is autotrophic.
• Reserve food material is in the form of polysaccharides mostly starch in green algae. Floridian starch in red algae, laminarin and lipid or mannitol in brown algae.
• Reproduction is mostly vegetative, asexual employing aplanospores, akinetes, palmella stage, zoospores etc. Sex organs are unicellular and non-jacketed. There is no embiyo formation after the gametic union. So embryo stage is absent in algae. Sexual reproduction may be isogamy, anisogamy and oogamy.
• Isogamous type. Gametes are morphologically similar but physiologically dissimilar, for Example, Chlamydomonas albaryanum.
• Anisogamous type. Fusion takes place between morphologically and physiologically dissimilar gametes, for example, C. beanie.
• Oogamous type. Fusion of active male gamete with large passive female gamete occurs to form a zygote, for example, C. coccifera.
• Four patterns of life cycle have been recognised in algae These are-
• Haplontic or monogenetic type. The plant showing this pattern has a predominant gametophytic phase which is followed by insignificant sporophytic for the diploid phase, being represented by zygote only.
• Diplontic type. In such plants, the sporophytic or diploid phase is predominant while the gametophytic or haploid phase remains insignificant and is represented by gametes only.
• Haplodiplontic or digenetic type. The plant has both gametophytic and sporophytic phases equally well represented. However, it may be further categorised into two types- isomorphic in which plants or gametophytic and sporophytic phases are more pathologically similar, and heteromorphic in which plants of two phases are morphologically dissimilar.
• Diplohaplontic with nutrigenetic type. Plants of two phases are well developed but the diploid or sporophytic phase is extended which shows two subphases- the first being dependent on gametophyte and the second being an independent diploid subphase that arises from the first subphase.
• Algae in contrast to fungi show the evolution of sex.

According to the traditional system of classification group algae is divided into the following classes:

1. Chlorophyta,
2. Charophyta,
3. Xanthophyta,
4. Chrysophyta,
5. Bacillariophyta,
6. Pyrrophyta,
7. Phaeophyta and
8. Rhodophyta.

According to the modem classification group, algae is divided as follows

Included in Protista according to the Whittaker system of classification

Chlorophyta (Green algae)

It is characterised by the presence of chlorophyll a and b, carotenoids. About 7,000 species are known, Chloroplasts normally contain pyrenoids. Starch is reserve food material.

Chlorophyceae exhibit a wide range of thallus organisations from unicellular, colonial, multicellular, filamentous to thalloid.

They reproduce asexually by zoospores, aplanospores, hypnospores and palmella stage. The sex organs are always unicellular. The zygote generally is the only diploid structure in the life cycle, for example, Chlamydomonas, Spirogyra and Ulothrix.

Phaeophyta (Brown algae)

Characterised by presence ofchlorophyll ‘a’ and ‘c’, carotenoids and fucoxanthins (2,000 species). The cells are uninucleated and the cell walls beside the cellulose and pectic substances contain gel-like polysaccharide algin (alginic acid)and the carbohydrate fucoid in(fucinic acid).

The presence offucosan vesicles in the cells is a characteristic feature of brown algae. Reserve food material is informofmannitol andlaminarin. The members of Phaeophyceae are mostly attached to the rocks by a holdfast. Some of the larger brown algae bodies are differentiated into holdfast, stipe and lamina.

Asexual reproduction is by tetraspores and aplanospores. Sexual reproduction varies from isogamy to oogamy. There is an alternation of generations as in higher plants Example Laminaria, Macrocystis, Sargassum (gulfweed), Dictyota etc.

Plant Kingdom NEET Mcqs

Rhodophyta. (Red algae). They are characterised by the presence of chlorophyll a. phycobilins (Phycocyanin and predominant and chi d in some cases red pigment Phycoerythrin).

About 5000 species are known, the reserve food is floridean starch, galactoside and floridosides. Red algae constitute an ancient group of plants and flagellated cells are absent in their life.

Sexual reproduction is oogamous. The life cycle of many red algae shows alternation of generations For example Batrachospermum involves the alternation of a succession (3 in number) of haploid somatic generations with a transitory diploid phase as represented by a zygote. Cytologically such a life cycle is called haplodiplontic.

Asexual reproduction is by means of monospores, carpospores, bispores etc.

The striking use of red algae is Agar. It is a gelatinous bleached material which is extracted from Gelidium and Gracilaria. Agar agar is used as a culture medium for bacteria. Calcareous red algae form coral reels.

NEET Biology Plant Kingdom Chlamydomonas

It is a motile, unicellular freshwater alga characterized by a pear-shaped body, two flagella, and a cup-shaped chloroplast containing one pyrenoid.

• Two basal granules, two contractile vacuoles, one red eye spot, and one nucleus are present. The nutritional mode is autotrophic, and it stores food as starch. Vegetative reproduction is nonexistent.
• Asexual reproduction under favourable conditions occurs through zoospores, which are generated in a zoosporangium by the process of bipartition. Aplanospores, hypnospores, and palmella spores are generated under adverse conditions.
• Sexual reproduction occurs in response to adverse environments. It is isogamous, anisogamous, and oogamous.
• The gametes amalgamate in an aqueous environment, resulting in external fertilization. The zygote enters a dormant state as a zygospore.
• Under optimal conditions, it germinates to generate meiozoospores by meiosis.
• A solitary meiozoospore generates one principal plant. Parthenogenesis occurs when gametes do not fuse, resulting in the formation of a zygospore-like structure known as a Parthenospore or zygospore.
• The life cycle is haplontic, wherein the entire generation is haploid, with the zygospore being the sole representation of the diploid phase.

NEET Biology Plant Kingdom Spirogyra

It is a freshwater multicellular filamentous free-floating alga. Single filament has a large number of cylindrical cells placed end to end. A cell has a cell wall which forms mucilage in contact with water, hence the plant called ‘pond silk’.

• In the cell, there is peripheral cytoplasm (primordial utricle) spiral-shaped chloroplasts, central vacuole, and nucleus suspended by cytoplasmic strands. Numerous pyrenoids are present.
• Mode of nutrition autotrophic and reserve food in the form of starch. Spirogyra cell takes essential salts and minerals through the exposed cell surface (cell membrane and cell wall).
• The Chloroplast of Spirogyra is left-handed with a wavy or smooth margin. ‘ Vegetative reproduction by fragmentation. Asexual reproduction by akinetes and aplanospores. Sexual reproduction is by conjugation. There is scalariform or ladder-like conjugation and lateral or chain conjugation.
• It is of further of two types direct and indirect conjugation. The former takes place in monoecious as well as in dioecious filaments while the latter takes place in monoecious filaments only. The female cell has the zygote which undergoes rest in the form of a zygospore.
• In favourable conditions, it germinates to produce 4 haploid nuclei, after meiosis out of which only one is functional and three degenerate. The germ tube is produced which gives rise to one filament

Plant Kingdom NEET Mcqs

Parthenogenesis occurs when a thick-walled, unfertilized resting gamete known as a zygospore (haploid) directly generates a new plant under favourable conditions. Life in Spirogyra is haplontic, with the zygospore being the sole representation of the diploid phase.

NEET Biology Plant Kingdom Ulothrix

1. This is a green alga of class Chlorophyceae, found in both fresh waters as well as seawater.
2. The most common freshwater species is U. zonata.
3. Some of the marine species are U. implexa, U. Jlacca and U. pseudolacca.
4. It is a multicellular, unbranched, filamentous alga with a basal holdfast or rhizoidal cell.
5. All cells, except the holdfast and apical cells, are almost of the same shape and size.
6. The cells are more in breadth than that of their height.
7. Each cell contains a single chloroplast which is C-shaped, collar-shaped, girdle-shaped or ring-shaped. One (U. roida) or many (U. zonata) pyrenoids are present. The cells are uninucleated.
8. Plants reproduce vegetatively by fragmentation. Akinetes are formed in U. zonata, U. acqualis, U. diaspora and U. oscillating.
9. Asexual reproduction takes place by three types of zoospores, i.e. quadriflagellate macrozoospores (large zoospore with 4 flagella), quadriflagellate microzoospores (small zoospores with 4 flagella), and biflagellate microzoospores (small zoospores with 2 flagella).
10. Plants reproduce also by aplanospores and Palmella stage.
11. Sexual reproduction in Ulothrix is isogamous. Ulothrix is dioecious, and fusion takes place between two gametes belonging to two separate filaments. Zygospore thus formed undergoes perennation under unfavourable conditions.
12. When favourable conditions approach, it germinates undergoes meiosis and form haploid lothario. Thus life cycle is haplontic. The main plant body is haploid and only the zygote represents the diploid phase.

Economic Importance Of Algae

1. As food. Ulva, Laminaria, Porphyra, Caulerpa etc. are used as food. Chlorella contains proteins and all vitamins from A-D. It is also used as food in space travel.

1. Utilization of marine algae as human food. The marine algae are of considerable importance in food value. They are often mixed with rice and fish and served as a base for soups, and condiments and eaten alone as salads.
2. Utilization of freshwater algae as human food. Chlorella is rich in protein and carbohydrates. Spirulina plalensis is one of the richest sources of protein, containing 40- 50 per cent crude protein.
3. The mucoproteinic constituents of the cell wall are easy to digest thus making Spirulina a good item for both, human beings and animals.
4. Utilization of algae as fish food. Algae serve as primary food for fish and other small aquatic animals. In freshwater lakes and ponds, Oedogonium, Spirogyra, Microspora, Ulothrix, Cladophora, Pithophora etc., serve directly as fish food.

2. In Industry

1. Agar-agar is produced from Gracilaria and Gelidium.
2. Algin is prepared from Ascophyllum, Macrocystis and Laminaria. It is used in ice creams.
3. Carrageenan is prepared from Chondrus Crispus (Irish moss). It is used in chocolate, jelly, ice-creams, etc.
4. Iodine is prepared from Ascophyllum, Laminaria, Fucus, and Ecklonia.
5. Bromine is obtained from red algae Polysiphonia and Rhodomela.
6. Alginic acid is obtained from Macrocystis, Nereocystis, Sargassum, Fucus and Laminaria.

3. Nitrogen fixation. Nostoc, Anabaena and many other genera of Cyanophyceae fix the atmospheric nitrogen and increase the fertility of the soil.

4. Medicines,

1. The antibiotic ‘chlorellin’ is prepared from Chlorella.
2. Chara is larvicidal and helps in the eradication of malaria.
3. Alginic acid stops bleeding and is also used in the preparation of emulsions.
4. Agar-agar is used as a laxative.

Plant Kingdom NEET Syllabus

5. Research Work,

1. Chlorella is used in many experiments of photosynthesis.
2. Acetabularia is used in many genetic experiments.
3. Water Bloom. Microcystis, Anabaena and Oscillatoria form the water bloom.
4. Parasitic algae. Cephaleuros viresus is a parasitic alga and causes ‘red rust of tea.’
5. Coffea is a parasite of the coffee plants.
6. Algae and space travel. The biologists are utilizing Chlorellapyrinoidosa as a possible food source in space flight.
7. Algae as fodder. The spa y/eeds are used as fodder for cattle example Macrocystis, Fucps, Laminaria.

• Linnaeus divided flowering plants into 23 classes, using the number and position of stamens. Monandria is a class with a single stamen Example Canna, Icosandria class includes plants with 20 or more stamens.
• Plant kingdom is divided into two subkingdoms i.e. phanerogamae and cryptogamae. Cryptogamae includes non-flowering plants such as algae, fungi, lichens, mosses and ferns.
• All flowering plants bear seeds and are included in Phanerogamae. The non-flowering cryptogams are divided into divisions Thallophyta, Bryophyta and Pteridophyta. Phanerogamae are also known as spermatophyta and are divided into gymnospermae and angiospermae.
• Kingdom Plantae is a large group of organisms which are primarily eukaryotic, multicellular and photosynthetic although some of them are unicellular as well. They include red, brown and green logic. bryophytes and vascular plants or traehcophytn. The latter comprises Ptcridophyta, Gymnosperms and Angiosperms.
• Red algae comprise a distinct, primitive marine group based unicellular to multicellular plant or coral-like. Phycobllin pigments provide a red colour to this group.
• Brown algae group also called phaeophyta are mostly marine, max grow up to 40-bO m. Larger forms such as laminaria have lamina which is photosynthctic. stemlike stipe and holdfast which anchors them to rocks.
• Green algae also called chlorophyta are chiefly freshwater forms. These plants are of different shapes and sizes.
• Some green algae ate epiphytic or epizoic while others have symbiotic relationships with fungi Example Lichens. live photosynthetic pigments present in their green algae ate chlorophyll a and chlorophyll b. They store starch and have cell walls made up of cellulose. The reproductive stage has flagellated gametes and asexual zoospores.
• Multicellular algae are evolutionarily older than land plants.
• Bry ophytes (moss plants) are small erect land plants growing densely in moist places. They have leaf-like, stem-like and root-like structures.
• These plants lack vascular tissue. Moss plants are gametophytes which develop from haploid spores. Male and female organs are called antheridia and archegonia respectively. The haploid and diploid phases alternate with each other and this is called the Alternation of generations.
• Vascular plants are diverse and dominant among land plants. Some may adapt to an aquatic mode of life secondary. The characteristic organs are root, stem and leaves which perform different functions and adapt to diverse environments.
• Ferns or pteridophytes are primitive vascular plants with variously shaped leaves. The stem of these plants may be an underground rhizome or a trunk as in tree ferns.
• The roots are of an adventitious type. Diploid sporophyte is dominant phase. Hie sporophyll produces sporangia in soil where haploid spores me produced by mciosis.
• The spores germinate to produce small ganirlnpliytc called prothallus which is heard in archegonia. Die zygote formed by the fusion of male and female gamete cells develops into a sporophytic phase, thus there is an alternation of generations.
• The plants having vascular tissue which resembles the windpipe of animals are called Trnchcophytes. Gyninospenns arc vascular plants which reproduce by forming naked seeds and water is not essential for fertilization.
• Ovules or megasporangia formed on sporophylls contain the egg cells. Pollen sacs or microsporangia produce pollen grains which produce male gametes.
• The zygote formed as a result of fertilization develops into an embryo within the ovule which becomes the seed. Seeds are naked in Gymnosperms.
• In cycas, megasporophylls are not organised in definite cones.
• Conifers (like pine) have one main axis of growth, with the trunk increasing girth as the tree increases in height. Angiosperms may be annuals, biennials or perennials and many survive for hundreds of years and grow indefinitely.
• Their size may range from 1 mm ( Wolffia) to 110 m (Eucalyptus). These angiospermic plants have definite roots, stems and leaves which may get modified to perform specific functions.
• They also get modified accordingly in the case of xerophytes, hydrophytes and mesophytes. Angiosperms are classified as monocots and dicots. The former have one cotyledon in the embryo and the latter have two cotyledons respectively.
• Monocots include cereals, bamboo, palms, bananas, lilies and orchids.
• Dicots include hard woody trees, pulses, most vegetables and fruits, many spices, beverages crops and many ornamental flowering plants.

Plant Kingdom NEET Notes

NEET Biology Plant Kingdom Quanta To Memory

• Karl. W. Von Nageli. Swiss botanists distinguished blue-green algae from algae.
• M.O.P. Lyenger is regarded as the father of Indian psychology (Algology).
• Linnaeus provided the term algae, for hepaticae and others but used it for its present meaning by A.L. de Jussieu (1789) Phycology/Algology. Branch of botany which deals with the study of alga.
• In Thallophyta. Sex organs are non-jacketed and unicellular Ectocarpus has separate haploid (n) and diploid (2n) filaments and exhibits isomorphic alternation of generations.
• Laminaria has a heteromorphic alternation of generations.
• Batrachospermum. found in freshwater is red algae but it is violet in colour.
• From Gelidium. (red algae), agar is obtained commercially from Charais submerged freshwater green alga. It has nodes, internodes and crystals of calcium carbonate.
• Porphyra. An edible form of red algae is cultivated in the shallow seas of Japan.
• Oedogonium. It has ring-like markings called cap cells. These cap cells are capable of division, sexual reproduction is oogamous. It is of two types:
• Macrandrous: Antheridia produce normal-sized filament
• Natutandious: Anlheridia produces a special dwarf male filament called nannandria.
• Phycocolloid. It is a mucopolysaccharide present in and over die walls of red and brown algae like alginic acid, brown algae, agar and carragennin in red algae.
• The Sargasso Sea is a part of the Atlantic sea and is covered by pieces of Sargassum (Gulf weed).
• Chloroplast is reticulate shaped in Morgotia, oedogonium.
• Chloroplast is star-shaped in Zygnema.
• Green algae Cephleuros causes red rust in tea and coffee.
• Carposporophyte. The post-fertilization, product produced in some algae is carpogonium is called carposporophyte.
• Carpospores on germination form a structure which resembles algal chaurasia and is called chaurasia stage Example Batrachospermum.
• Gongrosira stage of Vaucheria—Palmella stage of chlamydomonas.
• The number of caps in oedogonium cells is indicated by the number of times a cell has divided.
• Reticulate chloroplast is found in Oedogonium and pyrenoids are located on every point of cross section of bonds of chloroplasts.
• Chlamydomonas: Thrives in water richin ammonium salts. Some live in saline water and even in snow Example C. nivalis.
• Dictyosomes are present in Chlamydomonas.
• Location of contractile vacuole: Just below blepharoplasts in Chlamydomonas In Chlamydomonas. Volutin granule is reserve food present in the cytoplasm. 14 Aplanospore is produced singly.
• Hypnospores: contain haematochrome a red pigment.
• Red snow- Imperial red colour to snow by Chlamydomonas nivalis.
• Gametes of Chlamydomonas are without cell walls. Hologamy. When the whole organism acts as a gamete and fuses to form a zygote.
• Pigments entrap colour in double bonds In algal plants thalamus is Heterotrichous i.e. has different filaments. The body has prostrate branchings Example Coleochete, Stigeoclonium, Fristschiella, and Chantransia.
• Pyrenoid bodies never store oil and glycogen in algae. In algae the sex organs are naked and as a result of fertilisation the oospore or zygospore is formed but the zygote never formed.
• Alternation of generations is generally absent but occurs in Cladophora, Dictyota, and Ulva.
• Microcystis gives blue blue-green colour to the sea Trichodesmium erythrin gives a red colour to the sea.
• Carrageenan. It is a sulphated polysaccharide similar to Agar obtained from the cell walls of Gigartina and Chondrus. It is used as a thickening agent for food products, especially puddings.
• Apart from Porphyra, Chondrus (Irish Moss) is the most popular edible Red alga. Also used in pharmaceuticals including laxatives and cosmetics. Sargassum multiplies fast by fragmentation In Ulothrix, cytoplasm is peripheral.
• The zoospore of Lothario is pear-shaped and attaches itself to a solid substratum by a pointed end after swimming for some time.
• SPIROGYRA= Pond’s Silk
• Spirogyra genesis is a fixed species with holdfast and the cell just above is? gamete and above this cell represent male gamete. Zygospore has chloroplast Chlorella a green alga that is rich in proteins (50%) and is used in space research for food and C02-02 balance.
• Agar-agar is a starch-like polysaccharide which is obtained from the red algae Gelidium, which is used in medicines. Fucoxanthin is a pigment in brown algae which gives a brown colour to the algae.
• Natutandious: Anlheridia produces a special dwarf male filament called nannandria.
• Phycocolloid. It is a mucopolysaccharide present in and over die walls of red and brown algae like alginic acid, brown algae, agar and carragennin in red algae.
• The Sargasso Sea is a part of the Atlantic sea and is covered by pieces of Sargassum (Gulf weed).
• Chloroplast is reticulate shaped in Morgotia, oedogonium.
• Chloroplast is star-shaped in Zygnema.
• Green algae Cephleuros causes red rust in tea and coffee.
• Carposporophyte. The post-fertilization, product produced in some algae is carpogonium is called carposporophyte.
• Carpospore on germination forms a structure which resembles algal chaurasia and is called chaurasia stage Example Batrachospermum.
• Gongrosira stage of Vaucheria—Palmella stage of chlamydomonas.
• The number of caps in oedogonium cells is indicated by the number of times a cell has divided.
• Reticulate chloroplast is found in Oedogonium and pyrenoids are located on every point of cross section of bonds of chloroplasts.
• Chlamydomonas: Thrives in water richin ammonium salts. Some live on saline water and even in snow Example C. nivalis.
• Dictyosomes present in Chlamydomonas.
• Location of contractile vacuole: Just below blepharoplasts in Chlamydomonas In Chlamydomonas. Volutin granule is reserve food present in the cytoplasm. 14 Aplanospore is produced singly.
• Hypnospores: contain haematochrome a red pigment.
• Red snow- Imperial red colour to snow by Chlamy Domonas Nivalis.
• Gametes of Chlamydomonas are without cell walls. Hologamy. When the whole organism acts as a gamete and fuses to form a zygote.
• Pigments entrap colour in double bonds In algal plants thalamus is Heterotrichous i.e. has different filaments. The body has prostrate branchings Example Coleochete, Stigeoclonium, Fristschiella, and Chantransia.
• Pyrenoid bodies never store oil and glycogen in algae. In algae the sex organs are naked and as a result of fertilisation the oospore or zygospore is formed but the zygote never formed.
• Alternation of generations is generally absent but occurs in Cladophora, Dictyota, and Ulva.
• Microcystis gives blue green colour to the sea Trichodesmium erythrin gives a red colour to the sea. Carrageenan. It is a sulphated polysaccharide similar to Agar obtained from the cell walls of Gigartina and Chondrus.
• It is used as a thickening agent for food products, especially puddings. Apart from Porphyra, Chondrus (Irish Moss) is the most popular edible Red alga.
• Also used in pharmaceuticals including laxatives and cosmetics. Sargassum multiplies fast by fragmentation In Ulothrix, cytoplasm is peripheral. The zoospore of Lothario is pear-shaped and attaches itself to a solid substratum by a pointed end after swimming for some time.
• Spirogyra= Pond’s Silk
• Spirogyra genesis is a fixed species with a holdfast and a cell just above is. gamete and above this cell represent male gamete. Zygospore has chloroplast Chlorella a green alga that is rich in proteins (50%) and is used in space research for food and C02-02 balance.
• Agar-agar is a starch-like polysaccharide which is obtained from the red algae Gelidium, which is used in medicines. Fucoxanthin is a pigment in brown algae which gives a brown colour to the algae.

Plant Kingdom NEET Mcqs

NEET Biology Plant Kingdom Questions For Competitive Examinations

Question 1. Basal cell of ulothrix is :

1. Antheridium
2. Meristematic
3. Holdfast
4. Zoogonidium.

Answer: 3. Holdfast

Question 2. Kelps are:

1. Freshwater algae
2. Marine algae
3. Terrestrial plants
4. Amphibious plants.

Answer: 2. Marine algae

Question 3. Algae are important to human beings as they :

1. Can be turned into an important diet in future
2. Purify atmosphere
3. Can be grown in the water tank
4. None of the above.

Answer: 2. Purify atmosphere

Question 4.‘Non-motile’ gametes occur in :

1. Ulothrix
2. Spirogyra
3. Funaria
4. Selaginella.

Answer: 2. Spirogyra

Question 5. Thin-walled non-flagellate spores are :

1. Zoospores.
2. Aplanospores
3. Hypnospores
4. Zygospores.

Answer: 2. Aplanospores

Question 6. Life cycle of spirogyra/chlamydomonas is :

1. Haplobiontic/haplontic
2. Diplobiontic
3. Haplodiplobiontic
4. Diplontic.

Answer: 1. Haplobiontic/haplontic

Plant Kingdom NEET Mcqs

Question 7. Spirogyra filaments increase in length due to :

1. Basal cells
2. Division in middle cells
3. Rhizoidal cells
4. All green cells.

Answer: 4. All green cells.

Question 8. Which of the following are not seed producers?

1. Puccinia and pinus
2. Fern and funeral
3. Funaria and focus
4. Ficus and chlamydomonas

Answer: 2. Fern and funeral

Question 9. Algae attached to stones are called :

1. Monolithic
2. Epiploic
3. Epilithic
4. None of the above.

Answer: 3. Epilithic

Question 10. Algae are useful because they :

1. Are large in number
2. Purify the atmosphere
3. Are used in alcoholic fermentation
4. Are used in the study of photosynthesis.

Answer: 2. Purify the atmosphere

Question 11. People recovering from long illness are often advised to include alga spirulina in their diet because it:

1. Is rich in protein
2. Has antibiotic properties
3. Makes the food easy to digest
4. Restores the intestinal microflora.