NEET Biology Nervous System

Systems of Coordination.

1. Nervous system. Fast, specific with the electrochemical transmission, along nerve fibers
2. Endocrine system. Slow, diffused with chemical transmission through body fluids.
3. Immune system (antigen-antibody reactions)
4. Neurology. Study of morphology, physiology, and pathology of the nervous system.
5. Neurophysiology. Physiology or working of the nervous system.

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Nervous System Notes For Neet

NEET Biology Role Of The Nervous System

1. The nervous system illustrates the activities of different organs and the entire organism.
2. The nervous system links the various organ systems and coordinates all their activities.
3. It ensures the integrity of the organism.
4. The unity of an organism and its internal environment is affected and maintained through the nervous system.
5. Man’s brain is the material basis of thinking, memory, and good speech.
6. It stimulates or inhibits the activities of muscles and glands to evoke a response to the received information.
7. Special senses such as vision, hearing, smell, taste, and touch produced by information provided by sense organs are associated with the nervous system.

NEET Biology Nervous System Neuron

1. The fundamental components of nervous tissue are neurons, which originate from the ectoderm. Each neuron comprises a cell body, or cyton, containing a nucleus and many nerve fibers, classified into two categories.
2. An axon is an efferent process as it transmits impulses outward. The terminal branches of the axon, known as telocentric, possess end knobs that release neurotransmitters facilitating impulse conduction.
3. The branching processes of dendrites are afferent as they receive impulses for the neuron.
4. Nerve impulses are transmitted from the axon terminals of one neuron to the dendrites of another. The convergence of the two is referred to as a synapse.

NEET Biology Constituents Of the Nervous System

1. A central nervous system is composed of the brain and spinal cord. It contains nerve centers for all sensations. The brain and spinal cord are covered by protective membranes called meninges and their cavities are filled with cerebrospinal fluid.
2. The peripheral nervous system consists of various nerves which conduct impulses to all parts (Spinal and Cranial nerves).
3. The autonomic nervous system illustrates the working of viscera composed of sympathetic and parasympathetic nervous systems.
4. The central nervous system is made of nerve bodies forming the grey matter and of nerve fiber tracts which form the white matter.
5. The peripheral nervous system consists of nerves made of nerve fibers and nerve cell bodies located in the brain, spinal cord, and ganglia.
6. The autonomic nervous system consists of nerve cell bodies, their nerve fiber, and nerve plexies. However, all three divisions of the nervous system are connected intimately both structurally and functionally.

Structure And Function Of Neurons NEET

Brain. The brain reaches its highest development in mammals with better intFor exploration and mastery over the environment. The cerebral hemisphere reaches the status of a dominant inter-example rating part of the brain and acts as a coordinating center of the brain.

1. The cerebral hemispheres are immense projecting forwards above the olfactory lobes and backward above the diencephalon and mid-brain. The two hemispheres are separated by it deep median fissure.
2. Each hemisphere is further divided In an oblique Sylvimi (IsMire into an anterior frontal lobe and a posterior lateral temporal lobe
3. The cerebrum or cerebral hemispheres have a thick roof called a ‘neopallium’ in mammals, it is formed by upgrowth of the lateral portions of the pallium, but it differs histologically from the pallium in having a larger number of neurons which are arranged in layers of the cortex and medulla.
4. The cortex is further increased by many curved depressions or sulci and lobes or ‘gyri’ (absent in rabbits). Each hemisphere has a complex lateral ventricle, each ventricle has a middle body from which three prolongations come run forward, backward, and outward.
5. Above the lateral ventricles is a band of nerve fibers called corpus callosum which joins the neopallium or cortex of the two cerebral hemispheres, the anterior part of the corpus callosum is bent to form ‘menu while the posterior part is bent downwards and forwards forming splenium.
6. Below the corpus callosum is a band of longitudinal fibers forming the ‘fornix’. Its main body is formed by the union of two sets of fibers called fimbriae or taeniae hippocampi. Between the corpus callosum and fornix is a septum peculium having a small cavity called pseudocoel or 5th ventricle, which is not a true ventricle but a space between the two hemispheres.
7. The floor of the hemispheres forms anterior corpora striata and postero-lateral hippocampus which serves as an olfactory center, the median commissure of it is called psalterium or lyra, and that of corpora striata is the anterior commissure.

1. Running from the anterior commissure to the optic chiasma is a delicate membrane of the lamina terminals which marks the anterior boundary of the 3rd ventricle.
2. The cerebral hemispheres receive impulses from visual, auditory, olfactory, tactile, and peripheral receptors and they initiate voluntary motor impulses which are carried by bundles of nerve fibers to muscles. The cortex For exampleates the impulses and organizes and for example, rates them into coordinated activities.
3. The diencephalon is small and hidden dorsally by the hemispheres, it has a laterally compressed third ventricle or diaconal whose roof is formed by a delicate velum interpositum.
4. The side walls of the diencephalon or optic thalami are made of a thick mass of white and grey matter on the external surface of each thalamus near the anterior end is a rounded corpus geniculatum. The floor of the diencephalon is called the hypothalamus.
5. Recently a potent substance called hypothalamic D has been extracted from the hypothalamus which stimulates the production of adrenotrophic hormone of the pituitary gland.
6. The hypothalamus is composed of four parts optic chiasma, infundibulum and tuber cinereum, pituitary gland, and corpus albicans.
7. The diencephalon is a relay center of impulses from the posterior For example going to the cerebral cortex, the thalami are the centers of exploration and activity and for recognition of sensations of heat, cold, pain, and body movements.
8. Mid brain has two pairs of optic lobes called corpora quadri gemina. The floor of the mid brain is called crura cerebral which contains bundles of fibers. The canal which connects the 3rd ventricle with the 4th ventricle is called iter. Vision is controlled by the cerebrum and anterior parts of the anterior optic lobes.
9. The posterior optic lobes are auditory in function. The highly developed cerebellum is divided to form five lobes, central lobe vermis, two lateral lobes, and two outer floccular lobes.
10. In section, the cerebellum shows an outer thick layer of grey matter and a central mass of white matter, the two exhibit a tree-like pattern called arbor vitae.
11. The cerebellum is concerned with equilibrium and co-ordination of muscles and responses initiated by the cerebral hemispheres and carried out through the cerebellum Medulla oblongata lias a posterior choroid plexus below which is the fourth ventricle joined in front to the iter and behind to the central canal.
12. The medulla controls respiration, heartbeat, and blood vessels, it also has conduction pathways for impulses passing from cerebral hemispheres to the spinal cord and again in the opposite direction.

Neet Biology Nervous System Notes Pdf

NEET Biology Nervous System Spinal Cord

1. It is a cylindrical, cord-like, homogeneous extension of the medulla oblongata, measuring 42 to 45 cm in length and 2 cm in thickness in humans, extending from the neck to the lumbar region.
2. For instance, it traverses the neural canal of the spinal column and culminates in a slender extension known as the filum terminale. Growth ceases around 4 to 5 years of age.
3. In this structure, the white matter is located externally, while the H-shaped grey matter is situated internally, which is the inverse of the brain’s configuration.

NEET Biology Nervous System Peripheral

1. Cranial nerves. The peripheral nervous system consists of nerves connected to or arising from the central nervous system, it has cranial and spinal nerves. Twelve cranial nerve 1 – Olfactory (sensory). 11-Optic (sensory), lH-Oculomotor (motor), IV-Trochlear (motor), V-Trigeminal (mixed ), Vl-Abducens (motor), Vll-Facial (mixed), VIII-Auditory (sensory), IX- Glossopharyngeal (mixed), X-Vagus (mixed), Xl-Spinal accessory and XII-Hypoglossal (motor).
2. Sensory Cranial Nerves. Olfactory, Optic, and Auditory.
3. Motor Cranial Nerves. Oculomotor, Pathetic/Trochlear, Abducens, Accessory Spinal and Hypoglossal.
4. Mixed Cranial Nerves. Trigeminal, facial, Glossopharyngeal and Vagus,
5. Dentist’s nerves. Trigeminal (Vth nerve) [Has a swelling called gasserian ganglion from where it divides into 3 branches]
6. Number of Cranial Nerves. 10 pairs in amniotes (fishes and amphibians) and 12 pairs in amniotes (reptiles, birds, and mammals).
7. The facial nerve in frogs passes through the Gasserian ganglion but in mammals, it passes out through the Geniculate ganglion.
8. Glossopharyngeal and Vagus nerves in frogs pass out through the jugular ganglion but in mammals, they pass through the vagus ganglion. All are situated within the cranium.
9. The motor component of the vagus nerve controls sound production.

NEET Biology Nervous System Spinal Nerves

1. They originate from the spinal cord. Humans possess 31 pairs of spinal nerves.
2. Each spinal nerve comprises two roots: sensory (afferent) and motor (efferent) roots.
3. All spinal nerves possess a mixed composition. Each spinal neuron is partitioned into three rami.
4. The filum terminale and several posterior spinal nerves create a horse-tail-like structure known as the cauda equina within the neural canal.

NEET Biology Nervous System Multiple-Choice Questions

Question 1. Some Cells In Our Body Can Be Over A Foot Long, Are :

1. The Muscle Cells
2. The Bone Cells
3. The Nerve Cells
4. Gland Cells.

Answer: 3. The Nerve Cells

Question 2. Power Of Regeneration Is Lowest In :

1. Brain Cell
2. Liver Cell
3. Bone Cell
4. Muscle Cell.

Answer: 1. Brain Cell

Question 3. Nervous System Is Concerned With Two Important Functions :

1. It Regulates The External Environment And Responds To Internal Environment Through Sense Organs
2. It Regulates The Internal Environment And Responds To the External Environment Through Sense Organs
3. It Regulates The External Environment And Responds To Internal Environment Through Motor Nerve
4. It Regulates The Internal Environment And Responds To the External Environment Through Motor Nerves.

Answer: 4. It Regulates The Internal Environment And Responds To the External Environment Through Motor Nerves.

Question 4. A Neuron Is :

1. Structural And Functional Unit Of The Nervous System
2. Structural And Functional Unit Of The Endocrine System
3. Structural And Functional Unit Of The Muscular System
4. Structural And Functional Unit Of Skeletal System.

Answer: 1. Structural And Functional Unit Of The Nervous System

Nervous System MCQs For NEET

Question 5. Synapse Is A Term To Denote The :

1. Connection Between Two Arteries
2. Connection Between Two Veins
3. Connection Between Two Neurons
4. Connection Between Two Lungs.

Answer: 3. Connection Between Two Neurons

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Question 6. The Sympathetic And Parasympathetic Systems Constitute :

1. Reflex Arc
2. Reflex Action
3. Autonomic Nervous System
4. Peripheral Nervous System.

Answer: 3. Autonomic Nervous System

Question 7. The Central Nervous System Includes :

1. Brain And Spinal Cord
2. Spinal Nerves And Spinal Cord
3. Brain And Pineal Body
4. Only the Cerebrum And Medulla Oblongata Of the Brain.

Answer: 1. Brain And Spinal Cord

Question 8. The Central Nervous System; Cranio-Spinal System; Autonomic System And Receptor System In A Vertebrate Collectively Form:

1. Nervous Systempiamater
2. Circulatory And Nervous Systems
3. Reproductive And Nervous Systems
4. Digestive And Sympathetic Systems.

Answer: 1. Nervous Systempiamater

Question 9. The brain In a Frog Is Contained In the Cranium, Enveloped By a Connective Tissue Membrane Called :

1. Cranial Membrane
2. Meninges
3. Pericardium Membrane
4. Pia mater

Answer: 4. Pia mater

Nervous System MCQs For NEET

Question 10. The Brain Is Surrounded By An Outer Fibrous, Non- Vascular Membrane Called :

1. Pia mater
2. Neuromancer
3. Myomater
4. Dura mater.

Answer: 1. Pia mater

Question 11. The Inner Membrane surrounding the Brain Is :

1. Thin And Cartilaginous Pia mater
2. Thick And Muscular Pia mater
3. Thin And Vascular Pia mater
4. Thin Cardiac Membrane.

Answer: 3. Thin And Vascular Pia mater

Question 12. Pineal Stalk, A Slender Tubular Structure Arises From :

1. Ventral Surface Of Diencephalon
2. Dorsal Surface Of Diencephalon
3. Both Dorsal And Ventral Surfaces Of Diencephalon
4. Antero-Ventral Surface Of Diencephalon.

Answer: 2. Dorsal Surface Of Diencephalon

Question 13. Optic Chiasma Is Formed By The Crossing Over Of Two :

1. Olfactory Nerves
2. Oculomotor Nerves
3. Trochlear Nerves
4. Optic Nerves.

Answer: 4. Optic Nerves.

Question 14. Hypothalamus Forms The Floor And Lower Part Of :

1. Diacoel
2. Optocoel
3. Lateral Ventricle
4. Fourth Ventricle.

Answer: 1. Diacoel

Question 15. Two-Thirds Of Entire Brain Is Made Of:

1. Cerebellum
2. Medulla Oblongata
3. Flocculus
4. Cerebrum (Cerebral Hemisphere).

Answer: 4. Cerebrum (Cerebral Hemisphere)

Question 16. In Mammals, The Two Lobes Of the Cerebral Hemisphere Are Connected By a Large Distinctive Transverse Fibrous Bridge Of White Matter Called:

1. Corpus Spongiosum
2. Corpus Callosum
3. Corpus Commissures
4. Cerebral Connective.

Answer: 2. Corpus Callosum

Human Nervous System NEET MCQs

Question 17. Cell Bodies Of Neurons Bringing Afferent Information Into the Spinal Cord Are Located In the:

1. Dorsal Root Ganglia
2. Ventral Root Ganglia
3. Grey Matter Of Spinal Cord
4. White Matter Of Spinal Cord.

Answer: 1. Dorsal Root Ganglia

Question 18. In the Brain, Crura Cerebri Is A Structure Made Of:

1. Two Large Bands Of Nerve Fibres
2. Four Large Bands Of Nerve Fibres
3. Six Bands Of Nerve Fibres
4. Eight Bands Of Nerve Fibres.

Answer: 1. Two Large Bands Of Nerve Fibres

Question 19. The Roof Of Medulla Oblongata Is Thin And Piamater In This Portion Is Greatly Folded, Richly Vascular, And Pushed Into the Cavity Of the Medulla As :

1. Anterior Choroid Plexus
2. Posterior Choroid Plexus
3. Corpora quadrigemina
4. Optic Thalami

Answer: 2. Posterior Choroid Plexus

Questions Question 20. The Ventricles Of the Brain And Central Canal Of the Spinal Cord Arc Filled With A Fluid Called :

1. Cerebro-Spinal Fluid
2. Spinal Fluid
3. Cranial Fluid
4. Pericardial Fluid.

Answer: 1. Cerebro-Spinal Fluid

Question 21. Olfactory Lobes Of Human Are :

1. Fully Solid
2. Half Hollow And Half Solid
3. Fully Hollow
4. Become Solid At Puberty.

Answer: 1. Fully Solid

Human Nervous System NEET MCQs

Question 22. Nissl Granules In The Nerve Cell Bodies Are Actually :

1. Deep Staining Mitochondria
2. Lysosomes
3. Coiled Condensed Elements Of Rough Endoplasmic Reticulum
4. Multiple Number Of Golgi Bodies.

Answer: 3. Coiled Condensed Elements Of Rough Endoplasmic Reticulum

Question 23. The Anterior Choroid Plexus Is Located In Or Near The :

1. Diencephalon
2. Optic Lobes
3. Cerebrum
4. Cerebellum.

Answer: 1. Diencephalon

Question 24. The Pineal Body Is Considered As :

1. An Endocrine Gland
2. An Organ Concerned With Voluntary Action
3. An Organ Concerned With Vision
4. A Vestige Of 3rd Eye And Endocrine Gland.

Answer: 4. A Vestige Of 3rd Eye And Endocrine Gland.

Nervous System Recommended MCQs NEET Questions Question 25. If the Cerebral Hemispheres Of the Frog Are Removed, It:

1. Dies Immediately
2. Stops Feeding
3. Dies After Some Time
4. Behaves Normally.

Answer: 2. Stops Feeding

Question 26. In Human Brain, Corpora Quadrigemina Represents :

1. Fore Brain
2. Mid Brain
3. Hind Brain
4. Spinal Cord.

Answer: 2. Mid Brain

Question 27. The Cavity Of Spinal Cord Is Called :

1. Blastocoel
2. Enterocoel
3. Schizocoel
4. Central Canal.

Answer: 4. Central Canal.

Question 28. Brain Develops From :

1. Ectoderm
2. Mesoderm
3. Endoderm
4. Both Ectoderm And Endoderm.

Answer: 1. Ectoderm

Human Nervous System NEET MCQs

Question 29. The Function Of the Central Nervous System :

1. Controls Various Functions Of the Body
2. Directs Various Functions Of Body
3. Controls And Co-Ordinates The Activities Of Body
4. Conducts Impulses From One Part To The Other.

Answer: 3. Controls And Co-Ordinates The Activities Of Body

Nervous System MCQ for NEET Question 30. Corpora Striata Is A Part Of:

1. Cerebellum
2. Pons
3. Cerebrum
4. Fomix.

Answer: 3. Cerebrum

Question 31. Foramen Of Monro In Brain Is An Aperture Between :

1. Diacoel And Metacoel
2. Rhinocoel And Diacoel
3. 3rd And 4th Ventricle
4. Lateral And Third Ventricle.

Answer: 4. Lateral And Third Ventricle.

Question 32. Which Part Of The Brain Controls Muscular Coordination?

1. Cerebrum
2. Cerebellum
3. Medulla Oblongata
4. Diencephalon.

Answer: 2. Cerebellum

Question 33. A Deep Longitudinal Fissure Divides The Cerebrum :

1. Into Six Hemispheres
2. Into Four Hemispheres
3. Into Two Hemispheres
4. Into Eight Hemispheres.

Answer: 3. Into Two Hemispheres

Question 34. The Dendrites Of A Typical Vertebrate Motor Neuron, Compared To The Neuron’s Axon Arc Generally :

1. Longer
2. Larger In Diameter
3. More Branched
4. More Myelinated.

Answer: 3. More Branched

Question 35. The Parts Of Neurons That Perform Basic Cellular Functions, Such As Protein Synthesis, Are The :

1. Axons
2. Dendrites
3. Somas
4. Synaptic Knobs.

Answer: 3. Somas

Question 36. The Medulla Oblongata Continues As the Spinal Cord Which Runs In The Canal Of The :

1. Vertebral Column
2. Mid-Brain
3. Pituitary
4. Corpus Callosum.

Answer: 1. Vertebral Column

Question 37. It Is Said Injury To the Brain Is Permanent And Nerve Cells Cannot Rfor Exampleenerate. The Reason Is :

1. Absence Of Nucleus
2. Cells Are Very Long
3. They Lack Chromosomes
4. Part Of Chromatin Lies Outside The Nucleus.

Answer: 2. Cells Are Very Long

Question 38. Regulation Of Heart Beat And Respiration Is Controlled By:

1. Cerebrum
2. Cerebellum
3. Medulla
4. Pons Varolii.

Answer: 3. Medulla

NEET Chapter-wise MCQs On Nervous System

Question 39. The Volume Of Blood Supplied To The Brain Per Minute Is:

1. 1000 ml
2. 560 ml
3. 350 ml
4. 400 ml

Answer: 3. 350 ml

Nervous System MCQ for NEET Question 40. The third Ventricle Of a rabbit’s Brain Is Called :

1. Rhinocoel
2. Rhombocoel
3. Diacoel
4. Metacoel.

Answer: 3. Diacoel

Question 41. Learning Is Related To Which Part Of Human Brain?

1. Hypothalamus
2. Medulla
3. Cerebrum
4. Cerebellum.

Answer: 2. Medulla

Question 42. Thermo-Regulatory Centre In The Body Is :

1. Spinal Cord
2. Hypothalamus
3. Cerebellum
4. Pituitary.

Answer: 3. Cerebellum

Question 43. The Ganglion From Which Trigeminal Nerve Arises Is Called :

1. Vagus Ganglion
2. Cervical Ganglion
3. Neuroglia
4. Gasserian Ganglion.

Answer: 4. Gasserian Ganglion

Question 44. The Maximum Number Of Meninges In Animals Is/Are :

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

Answer: 2. Two

NEET Chapter-wise MCQs On Nervous System

Question 45. Foramen Of Magnadie Is Found In :

1. Optic Lobes
2. Crura Cerebri
3. Medulla Oblongata
4. Iter.

Answer: 3. Medulla Oblongata

Question 46. When Action Potential Jumps From One Node Of Ranvier To The Next, It Is Termed As :

1. Passive Conduction
2. Active Conduction
3. Saltatory Conduction
4. Neurotransmission.

Answer: 3. Saltatory Conduction

Question 47. Match The Type Of Respirator On The Right With Sense Organs Listed On The Left:

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

Answer: 1. 1-A  2-B   3-C  4-C   5-D

Human Nervous System NEET MCQs

Question  48. The Sensory Neuron Transmits Patterns Of Action Poiemials That Indicate :

1. The Type Of  Stimulus Received
2. The Intensity Of Stimulus Received
3. The Source Of The Stimulus
4. Both 2 And 3.

Answer: 4. Both 2 And 3.

Question  49. A Receptor That Detects The Position Of Parts Of Tire Body Is Called :

1. A Proprioceptor
2. A Hair Cell
3. A Mechanorcceptor
4. A Muscle Spindle.

Answer: 1. A Proprioceptor

Question  50. Regulatory Control Or Deep Body Temperature, Osmoregulation. Thirst And Hunger Occur In The :

1. Anterior Colliculi
2. Hypothalamus
3. Thalamus
4. Cerebellum.

Answer: 2. Hypothalamus

NEET Biology Organisms And Population Ageing And Death

NEET Biology Organisms And Population Ageing And Death Growth

• Growth: It refers to the augmentation in size and mass of an organism resulting from the synthesis of protoplasmic and apoplastic components. The event occurs when anabolism predominates in the overall metabolic process. There are three types of growth.
• Auxetic growth: In this instance, the volume of the organism expands due to the proliferation of body cells without an increase in the number of cells. The quantity of cells is predetermined in the majority of bodily regions. This sort of growth occurs in worms, rotifers, and a category of early chordates known as tunicates.
• Multiplicative growth :In this scenario, the cell count grows while the average cell size remains constant. All occurring decisions are mitotic. It frequently manifests in embryos and is a defining feature of the prenatal development of higher vertebrates.
• Accretionary growth refers to the mitotic division of reserve cells to augment and substitute the depleted differentiated cells.
• The various cells in the post-embryonic phase lose their ability to divide, resulting in this form of growth, for example. Development of epidermal cells from the Malpighian layer.
• Appositional growth: it entails the accumulation of new layers onto already established layers. It is a distinctive way of growth for stiff materials.

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NEET Biology Organisms And Population Ageing And Death Growth Rate

All creatures develop at a certain rate and cadence. The growth is a noticeable and quantifiable increase in the bulk of living material, which can be assessed by weighing at intervals.

Furthermore, the growth rate is variable, as organisms develop at distinct rates throughout different intervals. Rapid growth occurs throughout prenatal and teenage stages, which then decelerates during juvenile and post-adolescent phases, ultimately ceasing thereafter.

NEET Biology Organisms And Population

NEET Biology Organisms And Population Ageing And Death Growth Curve

The growth of an animal organ for a definite period when plotted against time forms a S-shaped Sigmoid curve. it is called a growth curve.

• An analysis of the Sigmoul curve shows ills’ glow it is slow in llu[•Birds and mammals stop growing when they have attained a certain characteristic age and size.
• it has been found that the factors that check the unlimited growth of animal tissues are many and varied. One such mechanism is the intrinsic antagonism between the factors that regulate the process of proliferation.
• The initial and final weight of an individual for any period of tune is lowed absolute prow lit. l.i Cell uniw3 Grow the old cells’ events during the inter of the cell cycle.
• During this phase, new materials such as nucleic acids, proteins, and protoplasmic bodies were formed. interphase is completed in three phases G, S and G, phases. Cell growth is an utmost important factor in the growth of multicellular animals. Cell growth leads to the division of cells also. Cell growth cannot be measured because of the small size and location of the cell.

1. Pattern Of Growth:

• Isometric growth: in this pattern of growth, an organ grows at the same mean rate as the rest of the body c.y. fishes and certain insects like locusts.
• Allnnictric growth: in this pattern of growth, an organ grows at a rate different from that at which the body grows mammals.

2. Methods Of Growth: Growth in animals is accomplished by several methods.

The most important of these are:

• Protoplasmic synthesis: Through this process, the growing animal synthesizes new l4ing matter from available food materials. The new raw materials are obtained from the digestion and absorption of complex food materials such as proteins, carbohydrates and lipids.
• Uptake of water: The amount of water that accumulates in the animal body during growth and development is enormous.
• intercellular deposition; Large-scale intercellular deposition of non-living matter occurs during growth. These substances consist mostly of jelly, fibres or the ground substances of cartilage and bone.

NEET Biology Organisms And Population

NEET Biology Organisms And Population Ageing And Death Hormonal Control Of Growth Rate in Man

• Thymosin hormone, released by the thymus gland, affects growth during the ages of 10 to 13 years (childhood).
• This era is characterized by sluggishness. Thyroxine and somatotropic hormone (STH) enhance development rate throughout late childhood.
• Growth accelerates throughout puberty (ages 14 to 18 years) due to heightened secretory activity of the pituitary and other endocrine glands.
• In males, testosterone regulates the development of secondary sexual organs and accessory sex traits, whereas in females, progesterone and estrogen perform similar functions.

NEET Biology Organisms And Population Ageing And Death Growth Factors

1. Epidermal Growth Factor (EGF): it stimulates epithelium to undergo mitosis – EGF is produced under the scab and is also produced in the sal4ary glands.
2. Fibroblast growth Factor (FGF): it stimulates the division of endothelial cells to heal the injured blood vessels.
3. Platelet-der4ed Growth Factor (PGF): it stimulates the mitosis of fibroblasts at the injured site to fill in the damaged area under the blood clot.

Measurement of Growth

• The amount of growth, an animal undergoes is expressed in terms of absolute growth or relative growth.
• The absolute growth rate is the increase in growth per unit of time.
• The relative growth rate is a relative increase in growth per unit of time. Comparisons of relative growth rates show many interesting patterns in animal growth.

Grow th Arresting Factors

• Birds and mammals stop growing when they have attained a certain characteristic age and size.
• it has been found that the factors that check the unlimited growth of animal tissues are many and varied. One such mechanism is the intrinsic antagonism between the factors that regulate the proliferation process.
• Another check on growth is cell destruction. Another mechanism is the hormonal cessation of growth in the long hones.

NEET Biology Organisms And Population Ageing And Death Regeneration

Regeneration, The ability of a living organism to replace out parts, regrow cast tY organs and transform the entire body from small fragments of it is called regeneration.

Categories of animal regeneration :

1. Restorative regeneration.
2. Restorative regeneration.

1. Restorative regeneration:  It is a common phenomenon amongst invertebrates and vertebrates. in sponges, an entire sponge may regenerate and form a group of a few cells. Similarly in Hydra, small pieces containing both germ layers may regenerate into new organisms.

Different Animal groups and their Regenerative body parts

Organisms And Population MCQs NEET

2. Reparative regeneration: It is quite common in the case of invertebrates and vertebrates. Amongst vertebrates, it is best observed in the Axolotl larva which can replace its tail, limbs and eyes. Tadpole the frog also shows a similar type of regeneration. Lizards can regenerate their tails but they are without bones. L4er in man has great power of reparative regeneration.

• Physiological regeneration: Replacement of cells of the body which are worn out due to constant activities.
• Compensatory hypertrophy: The regeneration of internal organs by enlarging one of the paired organs in case one is lost accidentally e.g. kidney
• Heleromorphosis: Regeneration that produces a part different from a lost part, e.g. crayfish.
• Mechanism of regeneration: given by T.H. Morgan

1. Morphallaxis: It is the reconstruction of an entire animal from a small fragment by reorganization of the existing cells.
2. Epimorphosis: It replaces a lost organ of the body by the proliferation of new cells from the surface of the injured part.

NEET Biology Organisms And Population Ageing And Death Ageing

• Gerontology: The field of developmental biology which deals with the study of the process of ageing is known as gerontology. it is the progress or deterioration in the structure and functions of cells, tissues and organs of the organism with time. it leads to death.
• Ageing: it is progress4e deterioration in this structure ami functions of cells, tissues, of pans ami organ systems. There is a progress decline in metabolism’s ability to replace worn-out cells, repair damaged tissues and resistance to diseases.

As old age progresses, skin becomes dry, and wrinkled, hair falls off, the body assumes a stooping posture, bones become brittle, and muscles, skin and cartilage become less elastic. Ageing affects the blood-vascular system. Sense organs like an ear. eyes etc. lose their intensities and kidney tubules are no more efficient
in the production of normal urine.

1. The heart pumps 35% less blood and sends 20% and 58% less blood to the brain and kidneys.
2. Oxygen carrying capacity of blood reduces.
3. The formation of new RBCs from the bone marrow slows down.
4. Calcium accumulates in the blood.

Cellular changes during ageing

1. There occurs reduction in tbe granular endoplasmic reticulum, partial degeneration of mitochondria (According to Rafsksy and Brarrows i958) and accumulation of lipofuscin granules.

1. Somatic mutations occur in, tbe cells of l4er, brain, heart and stomach.
2. Certain enzymes like aldolase, acctyl-cholincstrase, lactase dehydrogenase, glucose 6- phosphate dehydrogenase show reduced act4ities.
3. The number of chromosomes changes from the normal. Thus there are changes in DNA structure. in mice, dog and man, with increase in age, the l4er cells exhibit increased number of chromosomal aberrations,
4. Cellular membranes come to have calcium deposition, (According to Shock and Strehler i962) thus do not show select4e permeability.
5. Due to storage of certain pigments, the rate of cell d4ision decreases.

Extracellular changes: Extracellular changes include structural and functional changes in collagen.Collagen is most abundant extracellular protein which with ageing becomes less permeable, less flexible and insoluble. These changes interfere the normal functioning of the cells and induce the ageing.

Changes at the organ level include structural changes in the skin, muscles, bones etc. and also physiological changes in the vital organs like the heart, brain, kidney etc

NEET Biology Organisms And Population Ageing And Death Theories Of Ageing

1. The exact reason behind ageing is not clearly understood, and it is considered a cyclic phenomenon in one’s life. Several hypotheses have been proposed to explain the reason for ageing. They are as follows :
2. According to one view, free radicals accumulate with age which brings about oxidant reactions resulting in the deterioration of collagen and elastin etc. The oxidation of unsaturated fats results in the impairment of cell membranes in their select4e permeability.
3. The immunity system breaks down since the capacity of the formation of lymphocytes by bone marrow is lessened.
4. Ageing reduces the sensibility and effectiveness of the nervous control over the endocrine glands.
5. The high rate of metabolism results quickening of old age. probably CrT in,hc coded message of DNA increases due to old age which affects proper protein synthesis.
6. The tendency of ageing is intrinsic i.c. an organism will undergo ageing at a rat determined by the nature of genes.

Whatever views have been proposed, even today the understanding of the reasons for old age remains vague.

Organisms And Population MCQs NEET

Degrowth and death factors which result in degrowth

• The rate of breakdown surpasses that of synthesis reactions within the body.
• Internal reserves, shown as fat in adipose tissue, are metabolized to supply energy for essential living functions.
• Proteins from the living materials are also utilized for energy production.
• All these variables contribute to the depletion of living matter and lead to degrowth.
• Lipofuscin is the pigment associated with aging.
• With aging, there is a decrease in body weight by 12%, brain weight by 15%, and liver weight by 37%.
• The basal metabolic rate is 20%, the speed of nerve impulses is 5%, and the renal blood flow is 40%. to the brain is 80%. Consequently, there are few lymphocytes.

NEET Biology Organisms And Population Ageing And Death Death

it is a biological event which is due to a permanent breakdown in body functioning usually occurring due to a lack of oxygen supply to tissues. The cells stop normal functioning. it is an inescapable event of life.

Symptoms of clinical death: Symptoms of clinical death are Heartbeat, pulse and respiration stop 2 Pupils become fixed, remain dilated and do not respond to light.

Two main categories of causes of death

1. Weakening of tissues and vital organs: Weakening of tissues and vital organs, such as the heart, liver, kidney etc. result in physiological and metabolic disorders of irreversible nature. Sudden blockage of blood supply to the heart, and brain causes instantaneous death.
2. Due to ageing, there is a gradual breakdown in the immune system. Thus due to loss of body resistance, in old age man becomes susceptible to infectious diseases.

• Considerable growth occurs during the late embryonic or foetal period in the case of mammals.
• Replacement of old worn-out cells, metamorphosis and regeneration are the three main categories of post-embryonic development.
• Post-embryonic developments are characterised by growth, morphogenesis and differentiation finally. Ageing is also a post-embryonic stage.
• Animals grow at different rates at different periods of life.
• The human embryo is i50 /rm at the time of implantation and grows to about 50 cm during the gestation period.
• Growth may be auxetic or multiplicat4e accretionary. Fibroblast growth factors (FGFs) control cell proliferation in the development of limbs in chick, and insulin-like growth factors (iGFs) have a role in prenatal and postnatal growth of mammals. Growth hormone (Gil) secreted in the anterior lobe of the pituitary plays an important role in growth during childhood.
• Hydra and planaria have a capacity for regeneration. Nematodes show very low regenerat4e ability.
• Glial growth factors (GGFs) and other factors such as (FGFs iGFs) control amphibian limb regeneration.
• Compensatory regeneration: In the case of compensatory regeneration, the cells of l4er or kidney d4ide do not form an undifferentiated mass of cells or tissues, rather produce cells similar to themselves and maintain their function.
• Epimorphic regeneration: In the case of epimorphic regeneration as in Salamander, dedifferentiation occurs, and then these cells divide to form blastema which later on transforms into a correctly patterned limb structure.
• Reparative regeneration: The power of repairing only some body cells e.g. skin layer: gut lining: RBCs of blood etc.
• Morphallactic regeneration: The formation of the whole body from a body fragment by reorganizing the existing cells, e.g. Formation of components body of Hydra from a fragment.

NEET Biology Important Notes PDF

Changes in the weights of human body parts from birth to adulthood:

Life Span Of Selected Animals:

NEET Biology Organisms And Population Ageing And Death Quanta To Memory

• Vladimir Korenchevsky-Father of gerontology
• Werner Syndrome is a syndrome with signs of advanced ageing in the 20s.
• Eutyly: When the number of cells is constant both for the entire life and specific organs e.g. Ascaris.
• Nucleopycnosis: It is the shrinkage and condensation of chromatin leading to the death of the nucleus.
• Heteromorpliosis: it is a case when the regenerated part is different from the lost part.
• There are 60 quadrillion cells in an average adult human body weighing 60 kg but only 2 quadrillion in an infant.
  From the age of about 30 years, the human body becomes functionally less efficient by about 0.8% every year.
• The nucleus shrinks and stains deeply with advancing age. This is due to condensation of chromatin and leads to cellular death. Such a degenerat4e process is called nuclear pyknosis
• By the age of 75 years, the number of uriniferous tubules is reduced to half in men.
  Japanese have the highest life expectancy limit. The average life of a Japanese woman is 8i.5 years while that of a man is 76.2 years Regeneration was discovered by Trembley in Hydra.
• When reserve food material is utilised in the body, the process is called degrowth.
• in ascidian tadpole Example larva of Herdmcmia) there occurs retrogress4e metamorphosis.
• Maximum power of autotomy (self-mutilation) is found in holothurians (echinoderms). These organisms can throw off their internal visceral organs whenever threatened by a predator. in mammals, external body parts are not regenerated.
• But mammals have a great capacity to regenerate some of the internal organs. L4er has the maximum capacity of regeneration. Similarly, if one kidney is removed, the other enlarges and takes over the function of the lost kidney. Such a reparat4e regeneration is known as compensatory hypertrophy.

NEET Biology Organisms And Population Ageing And Death Questions

Question 1. Which one of the following is (rue during ageing?

1. Decrease in blood urea and GFR
2. increase in calcium content of arteries and cartilage
3. Decrease in cholesterol content of cornea and lens
4. Decrease in calcium content of arteries and cartilage.

Answer: 2. increase in calcium content of arteries and cartilage

Population Ageing And Death NEET Biology Notes

Question 2. in human beings the growth in height becomes nearly constant after the age of:

1. 15 years
2. 20 years
3. 30 years
4. 40 years.

Answer: 2. 20 years

Question 3. Which one of the following statements is correct concerning a test tube baby?

1. Fertilization of the egg is affected outside the body; the fertilized egg is then placed in the womb of the mother where the gestation is completed
2. Fertilization of the egg and growth of the embryo arc affected in a large test tube
3. A prematurely born baby reared in an incubator
4. Fertilization of the egg is affected in the female
5. Genital tract; the fertilized egg is then taken out and grown in a large test tube.

Answer: 1. Fertilization of the egg is affected outside the body; the fertilized egg is then placed in the womb of the mother where the gestation is completed

Question 4. The science of ageing is called :

1. Chronology
2. Odontology
3. Gynaecology
4. Gerontology.

Answer: 4. Gerontology.

Question 5. Ageing in many mammals including man may be due to:

1. Adverse changes in the environment
2. interaction between hereditary factors
3. Malnutrition and stress
4. All of the above.

Answer: 4. All of the above.

Question 6.Degenerat4e changes occur during :

1. Metamorphosis only
2. Parthenogenesis
3. Ageing only
4. Both in metamorphosis and ageing.

Answer: 4. Both in metamorphosis and ageing.

Question 7. As a person becomes old, a degenerat4e process sets in the body which causes:

1. A gradual alteration in the connect4e tissue components only
2. Increases the collagen content of the connect4e tissues
3. And increases the mucopolysaccharides content of most of the connective tissue.
4. Both in metamorphosis and ageing.

Answer: 4. Both in metamorphosis and ageing.

NEET Biology Important Notes PDF

Question 8. The growth in an animal includes:

1. increase in size
2. increase in weight
3. Synthesis of new proteins
4. All.

Answer: 4. All.

Question 9. The growth rate in most of the animals is:

1. Sigmoid for all organs
2. Linear for all organs
3. Uniform for all organs
4. Different for different organs.

Answer: 4. Different for different organs.

Question 10. The pigment of ageing is:

1. Haemoglobin
2. Hacmocyanin
3. Melanin
4. Lipofuscin.

Answer: 4. Lipofuscin.

Question 11. With the advancement of age, the hair of males starts thinning due to :

1. Falling of hair
2. Low ATP formation
3. Reduced rate of protein synthesis
4. None of the above.

Answer: 3. Reduced rate of protein synthesis

Question 12. The most accepted theory of ageing is :

1. Death of brain cells
2. Non-functioning of a – cells in the pancreas
3. Less RBC in blood
4. Non-functioning of thymus gland.

Answer: 4. Non-functioning of thymus gland.

Question 13. The growth rate in childhood is controlled by :

1. Thymosine
2. Thyroxine
3. Oestrogen
4. Progesterone
5. Testosterone.

Answer: 1. Thymosine

Question 14. Which is not connected with the theory of ageing?

1. Wear and tear
2. Neurohormonal changes
3. Epimorphosis
4. Metabolic rate
5. Somatic mutation.

Answer: 3. Epimorphosis

Question 15. Growth is an irreversible process found at :

1. Subcellular growth
2. Cellular growth
3. Organ growth
4. All of the above.

Answer: 4. All of the above.

Ecology Class 12 NEET Notes

Question 16. In animals, chalones are substances responsible for:

1. Regeneration
2. Ageing
3. Development
4. Parthenogenesis.

Answer: 2. Ageing

Question 17. Growth in l4ing being is called :

1. Accretion
2. intussusception
3. Aggregation
4. interaction.
5. Accumulation.

Answer: 1. Accretion

Question 18. if Hydra is broken into pieces:

1. Hydra will die
2. Hydra will undergo sexual reproduction
3. Some fragments will form a complete Hydra
4. Every fragment will grow into a complete Hydra

Answer: 4. Every fragment will grow into a complete Hydra

Question 19. Formation of the whole body from a fragment is:

1. Cpimorphosis
2. Morphallaxis
3. Epigenesis
4. Auxetic growth.

Answer: 2. Morphallaxis

Question 20. The correct sequence of growth curve for bacteria is:

1. Lag. log, stationary’ and decline
2. Lag. log, decline and stationery
3. Stationary, lag. log, decline
4. Decline, lag and log phase.

Answer: 2. Lag. log, decline and stationery

Question 21. Semilog of per minute growing bacteria is plotted against time. What will be the shape of the graph?

1. Ascending straight line
2. Sigmoid
3. Hyperbolic
4. Descending straight line.

Answer: 1. Ascending straight line

Question 22. Senescence is inhibited by :

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

Answer: 3. Cytokinin

Question 23. In which phase proteins for spindle Fibre formation are synthesized?

1. G-phase
2. G-phase
3. S-phase
4. Anaphase.

Answer: 3. G-phase

Question 24. The maximum life span of a dog in years is :

1. 5
2. 10
3. 15
4. 20.

Answer: 4. 20

Ecology Class 12 NEET Notes

Question 25. In the somatic cell cycle :

1. In Gjphase DNA content is double the amount of DNA present in the original cell
2. DNA replication takes place in S-phase
3. A short interphase is followed by a long mitotic
4. Phase.

Answer: 2. DNA replication takes place in S-phase

Question 26. The maximum growth rate occurs in :

1. Senescent phase
2. Stationary phase
3. Lag phase
4. Exponential phase.

Answer: 4. Exponential phase.

Question 27. Four healthy people in their twenties got involved in injuries resulting in damage and death of a few cells of the following. Which of the cells are least likely to be replaced by l4ing cells?

1. Osteocytes
2. Malpighian layer of skin
3. Liver cells
4. Neurons.

Answer: 4. Neurons.

Question 28. Based on cellular mechanisms there are two major types of regeneration found in the animals. Which of the following is the correct example of the type mentioned?

1. Morphallaxis- Regeneration of two transversely cut equal pieces of a Hydra into two small Hy draws.
2. Epimoiphosis – Replacement of old and dead erythrocytes with new ones.
3. Morphallaxis – Healing up of a wound in the skin.
4. Epimorphosis – Regeneration of crushed and filtered out pieces of a Planaria into as many new Planar- cans.

Answer: 1. Morphallaxis- Regeneration of two transversely cut equal pieces of a Hydra into two small Hy dras.

Question 29. Ageing of an animal’s body is associated with deterioration in its :

1. Connect4e tissue
2. Glandular tissue
3. Epithelial tissue
4. Both 1 and 2.

Answer: 2. Glandular tissue

Question 30. The modern idea about ageing is that our body slowly loses the power of defence against the invasion of germs and pathogens, this process starts with the
the disappearance of which organ?

1. Spleen
2. Thymus gland
3. Pituitary gland
4. Parathyroid gland.

Answer: 2. Thymus gland

Question 31. Match the items in Column I with Column II and choose the correct alternatives :

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

Answer: 1. 1 = A ,2= D, 3 = C, 4= E, 5 =B

Question 32. Which endocrine gland becomes inactive in old age?

1. Adrenal
2. Thyroid
3. Thymus
4. Pituitary.

Answer: 3. Thymus

Ecology Class 12 NEET Notes

NEET Biology Organisms And Population Ageing And Death Self Assessment Test Unit Reproduction

Question 1. A low statements describing certain features of reproduction are given below :

1. Gametic fusion takes place

2. Transfer of genetic material takes place

3. Reduction division takes place

4. Progeny has some resemblance with parents Select the options that are true for both asexual and sexual reproduction from the options given blow:

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

Answer: 3. 2 and 4

Question 2. The term ‘clone cannot be applied to offspring formed by sexual reproduction because :

1. Offspring do not possess exact copies of parental DNA.
2. DNA of only one parent is copied and passed on to the offspring
3. Offspring are formed at different times
4. DNA of parent and offspring are completely different.

Answer: Offspring do not possess exact copies of parental DNA.

Question 3. Amoeba and Yeast reproduce asexually by fission and budding respectively, because they are :

1. Microscopic organisms
2. Heterotrophic organisms
3. Unicellular organisms
4. Uninucleate organisms

Answer:  3. Unicellular organisms

Question 4. A few statements about sexual reproduction are given below :

1. Sexual reproduction does not always require two individuals
2. Sexual reproduction generally involves gametic fusion.
3. Meiosis never occurs during sexual reproduction
4. External fertilisation is a rule during sexual reproduction.

Choose the correct statements from the options below :

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

Answer:  2. 1 and 2

Question 5. A multicellular, filamentous alga exhibits a type of sexual life cycle in which the meiotic division occurs after zygote formation. The adult filament of this alga has

1. Haploid vegetative cells and diploid gametangia
2. Diploid vegetative cells and diploid gametangia
3. Diploid vegetative cells and haploid gametangia
4. Haploid vegetative cells and haploid gametangia

Answer:  4. Haploid vegetative cells and haploid gametangia

NEET Biology Organisms And Population

Question 6. The male gametes of rice plants have i2 chromosomes in their nucleus. The chromosome number in the female gamete, zygote and the cells of the seedling will be respectively.

1. 12, 24. 12
2. 24, 12, 12
3. 12. 24.24
4. 24, 12. 24

Answer: 3. 12. 24.24

Question 7. Given below are a few statements related to external fertilization. Choose the correct statements.

1. The male and female gametes arc formed an<i released simultaneously

2. Only a few gametes are released into the medium.

3. Water is the medium in a majority of organisms exhibiting external fertilization.

4. Offspring formed as a result of external fertilization have a better chance of survival than those formed inside an organism

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

Answer:  2. 1 and 3

Question 8. The statements given below describe certain features that are observed in the pistil of flowers.

1. Pistil may have many carpels

2. Each carpel may have more than one ovule

3. Each carpel has only one ovule

4. Pistil has only one carpel

Choose the statements that are true from the options below :

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

Answer:  1. 1 and 2

Question 9. Which of the following situations correctly describes the similarity between an angiosperm egg and a human egg?

1. Eggs of both are formed only once in a lifetime
2. Both the angiosperm egg and the human egg are stationary
3. Both the angiosperm egg and human egg are motile and transported
4. Syngamy in both results in the formation of zygote

Choose the correct answer from the options given below:

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

Answer:  2. 1 and 4

Question 10. The appearance of vegetat4e propagules from the nodes of plants such as sugarcane and ginger is mainly because:

1. Nodes are shorter than int models
2. Nodes have meristematic cells
3. Nodes are located near the soil
4. Nodes have non-photosynthetic cells

Answer: 2. Nodes have meristematic cells

Question 11. Which of the following statements, supports the view that elaborate sexual reproduction process appeared much later in the organic evolution?

1. Lower groups of organisms have a simpler body design

2. Asexual reproduction is common in lower groups

3. Asexual reproduction is common in higher groups of organisms

4. The high incidence of sexual reproduction in angiosperms and vertebrates.

Choose the correct answer from the options given below:

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

Answer: 3. 2 and 4

NEET Biology Organisms And Population

Question 12. Offspring formed by sexual reproduction exhibit more variation than those formed by asexual reproduction because:

1. Sexual reproduction is a lengthy process
2. Gametes of parents have qualitat4ely different genetic composition
3. Genetic material comes from parents of two different species
4. The greater amount of DNA is involved in sexual reproduction.

Answer:  3. Gametes of parents have qualitat4ely different genetic composition

Question 13. Choose the correct statement from among the following:

1. Dioecious (hermaphrodite) organisms are seen only in animals
2. Dioccies organisms are seen only in plants
3. Dioecious organisms are seen in both plants and animals
4. Dioecious organisms are seen only in vertebrates.

Answer: 4. Dioecious organisms are seen only in vertebrates.

Question 14. There is no natural death in single-celled organisms like Amoeba and bacteria because :

1. They cannot reproduce sexually
2. They reproduce by binary fission
3. The parental body is distributed among the offspring
4. They are microscopic

Answer: 2. They reproduce by binary fission

Question 15. There are various types of reproduction. The type of reproduction adopted by an organism depends on :

1. The habitat and morphology of the organism
2. Morphology of the organism
3. Morphology and physiology of the organisms
4. The organism’s habitat, physiology and genetic makeup

Answer:  1. The habitat and morphology of the organism

Question 16. Identify the incorrect statement.

1. In asexual reproduction, the offspring produced are morphologically and genetically identical to the parent
2. Zoospores are sexual reproduct4e structures
3. In asexual reproduction, a single parent produces offspring with or without the formation of gametes
4. Conidia are asexual structures in the Penicillium

Answer: 4. Conidia are asexual structures in Penicillium

Question 17. Which of the following is a post-fertilisation event in flowering plants?

1. Transfer of pollen grains
2. Embryo development
3. Formation of flower
4. Formation of pollen grains

Answer: 4. Formation of pollen grains

Question 18. The number of chromosomes in the shoot tip cells of a maize plant is shall be :

1. 20
2. 10
3. 40
4. 15

Answer:  3. 40

Question 19. Among the terms listed below those that are not correct names for a floral whorl are :

1. Androecium
2. Carpel
3. Corolla
4. Sepal
   1. 1 and 4
   2. 3 and 4
   3. 2 and 4
   4. 1 and 3

Answer:  3. 2 and 4

Question 20. The embryo sac is to ovule as is to an anther.

1. Stamen
2. Filament
3. Pollin grain
4. Androecium

Answer: 3. Pollin grain

Question 21. In a typically complete, bisexual and hypogynous flower, the arrangements of floral whorls on the thalamus from the outermost to the innermost is.

1. Calyx, corolla, androecium and gynoccium
2. Calyx, corolla, gynoecium and Androecium
3. Gynoecium, androecium, corolla and calyx
4. Androecium, gynoecium, corolla and calyx

Answer:  1. Calyx, corolla, androecium and gynoecium

Question 22. A dicotyledonous plant bears flowers but never produces fruits and seeds. The most probable cause for the above situation is:

1. The plant is dioecious and bears only pistillate flowers
2. The plant is dioecious and bears both pistillate and staminate flowers
3. Plant is monoecious
4. The plant is dioecious and bears only staminate flowers.

Answer: 4. Plant is dioecious and bears only staminate flowers

Question 23. The outermost and innermost wall layers of microsporangium in an anther arc respectively :

1. Endothecium and tapetum
2. Epidermis and endodermis
3. The epidermis and middle layer
4. Epidermis and tapetum

Answer: 4. Epidermis and tapetum

Question 24. During microsporogenesis, meiosis occurs in :

1. Endothecium
2. Microspore mother cells
3. Microspore tetrads
4. Pollen grains

Answer:  2. Microspore mother cells

Question 25. From among the sets of terms g4en below, identify those that are associated with the gynoecium.

1. Stigma, ovule, embryo sac, placenta
2. Thalamus, pistil, style, ovule
3. Ovule, ovary, embryo sac, tapetum
4. Ovule, stamen, ovary, embryo sac

Answer: 1. Stigma, ovule, embryo sac, placenta

Question 26. Starting from the innermost part, the correct sequence of parts in an ovule is:

1. Egg, nucellus, embryo sac, integument
2. Egg, embryo sac, nucellus, integument
3. Embryo sac, nucellus, integument, egg
4. Egg, integument, embryo sac, nucellus.

Answer: 2. Egg, embryo sac, nucellus, integument

Question 27. From the statements g4en below choose the option that is true for a typical female gametophyte of a flowering plant :

1. It is 8-nucleate and 7-celled at maturity

2. It is free-nuclear during the development

3. It situated inside the integument but outside the nucellus

4. It has an egg apparatus situated at the chalazal end

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

Answer: 3. 1 and 2

Question 28. Autogamy can occur in a chasmogamous flower if:

1. Pollen matures before the maturity of the ovule
2. Ovules mature before the maturity of pollen
3. Both pollen and ovules mature simultaneously
4. Both anther and stigma are of equal lengths.

Answer: 3.  Both pollen and ovules mature simultaneously

Question 29. Choose the correct statement from the following :

1. Cleistogamous flowers always exhibit autogamy
2. Chasmogamous flowers always exhibit geitonogamy
3. Cleistogamous flowers exhibit both autogamy and geitonogamy
4. Chasmogamous flowers never exhibit autogamy

Answer: 1. Cleistogamous flowers always exhibit autogamy

NEET Biology Organisms And Population

Question 30. A particular species of plant produces light, non-sticky pollen in large numbers and its stigmas are long and feathery. These modifications facilitate pollination by:

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

Answer: 3. Wind

Question 31. From among the situations given below, choose the one that presents both autogamy and goitnogamy.

1. Monoecious plant boating unisexual flowers
2. Dioecious plant carrying male or female  flowers
3. Monoecious plant with bisexual flowers
4. Dioecious plant with bisexual flowers

Answer:  3. Monoecious plant with bisexual flowers

Question 32. In a fertilised  Sac the haploid. diploid anti tnploul stntctutvs atv :

1. Syergid, zygote and primary endosperm nucleus
2. Synergid ,antipodal and polar nuclei
3. Amiposlal, synergid and primary endosperm nucleus
4. Synergid, polar nuclei and zygote.

Answer: 1. Syergid, zygote and primary endosperm nucleus

Question 33. In an embryo sac. the cells that degenerate after fertilisation arc :

1. Syncrgids and primary endosperm cell
2. Synergids and antipodals
3. Antipodals and primary endosperm cell
4. Egg and antipodals

Answer: 2. Synergids and antipodals

Question 34. While planning for an artificial hybridization programme involving dioecious plants, which of the following steps would not be relevant:

1. Bagging of the female flower
2. Dusting of pollen on the stigma
3. Emasculation
4. Collection of pollen

Answer:  3. Emasculation

Question 35. In the embryos of a typical dicot and a grass, true homologous structures are :

1. Coleorhiza and coleoptile
2. Coleoptile and scutellum
3. Cotyledons and scutellum
4. Hypocotyl and radicle

Answer: 2. Coleoptile and scutellum

Question 36. The phenomenon observed in some plants wherein parts of the sexual apparatus are used for forming embryos without fertilisation is called :

1. Parthenocarpy
2. Apomixis
3. Vegetat4e propagation
4. Sexual reproduction

Answer:  2. Apomixis

Question 37. In a flower, if the megaspore mother cell forms megaspores without undergoing meiosis and if one of the megaspores develops into an embryo sac, its nuclei would be :

1. Haploid
2. Diploid
3. A few haploid and a few diploid
4. With varying ploidy.

Answer: 2. Diploid

Question 38. The phenomenon wherein, the ovary develops into a fruit without fertilisation is called :

1. Parthenocarpy
2. Apomixis
3. Asexual reproduction
4. Sexual reproduction

Answer: 1. Parthenocarpy

Question 39. Choose the incorrect statement from the following :

1. In birds and mammals, internal fertilisation takes place
2. Colostrum contains antibodies and nutrients
3. Polyspermy is prevented by the chemical changes in the surface of the egg
4. In the human female implantation occurs almost seven days after fertilisation

Answer:  3. Polyspermy is prevented by the chemical changes in the surface of the egg

Question 40. Identify the wrong statement from the billowing ;

1. High levels of oestrogen trigger the ovulatory phase
2. Oogoninl cells start to proliferate and g4e rise to ova in regular cycles from puberty onwards.
3. Sperms released from seminiferous tubules arc poorly motile/non-mobile
4. Progesterone levels are high during the post-ovulatory phase of the menstrual cycle.

Answer:  2. Oogoninl cells start to proliferate and g4e rise to ova in regular cycles from puberty onwards.

Question 41. Spot the odd one out from the following structures concerning the male reproductive system :

1. Rate lists
2. Epididymis
3. Vasa efferentia
4. Isthmus

Answer: 4. Isthmus

Question 42. Seminal plasma, the fluid part of semen, is contributed by,

1. Seminal vesicle

2. Prostate

3. Urethra

4. Bulbourethral gland

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

Answer: 2. 1, 2 and 4

Question 43. Spermiation is the process of the release of sperm from:

1. Seminiferous tubules
2. Vas deferens
3. Epididymis
4. Prostate gland

Answer: 1. Seminiferous tubules

Question 44. A mature Graafian follicle is generally present in the ovary of a healthy human female around :

1. 5 – 8 days of the menstrual cycle
2. 11-17 days of menstrual cycle
3. 18-23 days of the menstrual cycle
4. 24 – 28 days of the menstrual cycle

Answer:  2. 11-17 day of menstrual cycle

Ageing And Death In Organisms NEET Study Material

Question 45. The acrosomal reaction of the sperm occurs due to :

1. Its contact with zona pellucida of the ova
2. Reactions within the uterine environment of the female
3. Reactions within the epididymal environment of the male
4. Androgens produced in the uterus

Answer: 1. Its contact with zona pellucida of the ova

Question 46. Which one of the following is not a male accessory gland?

1. Seminal vesicle
2. Ampulla
3. Prostate
4. Bulbourethral gland

Answer: 2. Ampulla

Question 47. The immature male germ cell undergoes division to produce sperm by the process of spermatogenesis. Choose the correct one concerning the above.

1. Spermatogonia have 46 chromosomes and always undergo meiotic cell division
2. Primary spermatocytes d4ide by mitotic cell d4ision
3. Secondary spermatocytes have 23 chromosomes and undergo second meiotic division
4. Spermatozoa are transformed into spermatids

Answer: 3. Secondary spermatocytes have 23 chromosomes and undergo second meiotic division

Question 48. Match between the following representing parts of the sperm and their functions and choose the correct option.

1. 1 -B  2-D 3-A   4-C
2. 1-D  2-C  3-A   4-B
3. 1-D  2-A  3-2   4-C
4. 1-B  2-A  3-C   4-D

Answer: 2. a-4 b-3 c-1 d-2

Question 49. Which among the following has 2.3 chromosomes?

1. Spermatogonia
2. Zygote
3. Secondary oOcyte
4. Ogonia

Answer: 3. Secondary oOcyte

Question 50. Match the following and choose die correct options :

1. Trophoblast 1. Embedding of blastocyst in the endometrium
2. Cleavage2. Group of cells that would differentiate as embryo
3. Inner cell mass 3. The outer layer of the blastocyst attached to the endometrium
4. Implantation 4. Mitotic d4ision of zygote Options

Answer: 2. Cleavage2. Group of cells that would differentiate as embryo

Question 51. Which of the following hormones is not secreted by the human placenta?

1. HCG
2. Estrogens
3. Progesterone
4. LH

Answer: 4. LH

Question 52. The vas deferens receives duct from the seminal vesicle and opens into the urethra as :

1. Epididymis
2. Ejaculatory duct
3. Efferent ductule
4. Ureter

Answer: 2. Enaculatory duct

Question 53. Urethral meatus refers to the following:

1. Urinogenital duct
2. Labia minora
3. Eimbriac
4. Infundibulum
5. Isthmus

Answer: 4. Infundibulum

Question 57. The method of directly injecting sperm into the ovum assisted by reproduct4e technology is called :

1. GIFT
2. ZIFT
3. ICSI
4. ET

Answer: 3. ICSI

Question 58. Increased iMR and decreased MMR in a population will:

1. Cause a rapid increase in the growth rate
2. Result in a decline in the growth rate
3. Not cause a significant change in the growth rate
4. Result in an explos4e population

Answer: 3. Not cause a significant change in growth rate

Question 59. Intensely lactating mothers do not generally conce4e due to the:

1. Suppression of gonadotropins
2. Hypersecretion of gonadotropin
3. Suppression of gametic transport
4. Suppression of fertilisation

Answer: 1. Suppression of gonadotropins

Organisms And Population MCQs NEET

Question 60. Sterilisation techniques are generally foolproof methods of contraception with least side effects. Yet, this is the last option for the couples because :

1. It is almost irreversible

2. Of the misconception that it will reduce sexual urge/ dr4e

3. It is a surgical procedure

4. Of lack of sufficient facilities in many parts of the country

Choose the correct option :

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

Answer: 4. 1, 2, 3 and 4

NEET Biology Plant Growth and Development Basic Features Of Development

• Growth: It is a biological phenomenon involving an increase in the quantity of metabolically active protoplasm, accompanied by an increase in cell number cell size or both.
• Reproduction: The process of producing the young ones of one’s type is called reproduction.
• Development: It is the development of a small, simple one-celled zygote into a large complex-celled adult plant or animal.
• Embryonic or Pre-natal period: It is the period of development of an animal from fertilization to the hatching or birth stage.
• Post-embryonic or Post-natal period: It is the period of changes or transformations which occur in an animal from hatching or birth up to death.
• Ontogeny: The total of events and progressive changes which transform a fertilized egg into a mature individual capable of reproducing is known as ontogeny.
• Reproductive unit: It is is unit produced from either one parent or two parents which undergo a series of developmental changes to give rise to the body of offspring which resembles the parent.
• Gamete: It is the structure produced by the male or female individual through meiosis (gametogenesis) in the sex organs, which takes part in fertilization to form a zygote.
• Zygote: It is the sexual fusion product of male and female gametes.
• Embryo: It is the stage of life history between fertilization and the hatching or birth of a young one. It is derived from the fertilized egg or zygote. The embryo is diploid. It is formed as a result of fertilization and subsequent changes.
• Blastogenesis: The process of development of the progenies from reproductive units such as fragments and buds is called blastogenesis. The process is common in those individuals who are produced by asexual reproduction.
• Embryogenesis: The process of development of the embryo from the zygote produced by the fusion of male and female gametes in sexual reproduction is called embryogenesis. This process occurs in individuals who reproduce by sexual reproduction.

Read and Learn More NEET Biology Notes

• Gametogenesis: The production and differentiation of male and female haploid gametes from gonads.
• Fertilization: The union or syngamy of haploid nuclei of male and female gametes to form a diploid zygote is called fertilization.
• Cleavage and Blastula: A series of repeated mitotic divisions of an egg that form a cluster of balls of cells (blastomeres) is called blastula.
• Gastrulation: The morphogenetic movements of cells of the blastula to give rise to germinal layers, ectoderm, endoderm and mesoderm is called gastrulation. The embryo thus formed with archenteron is called gastrula.
• Growth: Growth is a permanent increase in the synthesis of new nuclear material and cytoplasm.
• Differentiation: It refers to events by which parts become different from one another. It may be morphological, chemical, behavioural, or differentiation.
• Spermatogenesis: The process of formation of sperms from the sperm mother cell of the testis. It involves the following phases:

Plant Growth And Development Notes For Neet

Multiplication phase: The sperms are formed from the sperm mother cells, present in the germinal layer of seminiferous tubules of the testis. Some of the mother cells enlarge and divide mitotically to form spermatogonia.

1. Growth phase: Some of them enter a period of growth and are called primary spermatocytes which are diploid.
2. Maturation phase: These cells divide meiotically to form two haploid, secondary spermatocytes. Each secondary spermatocyte again divides. Thus one primary spermatocyte forms four haploid spermatids.

• Spermiogenesis (Spermateliosis): The process of conversion of spermatid into motile spermatozoa is called spermiogenesis.
• It involves movements of cell organelles characteristics of mature sperm such as shrinking of nucleus forming the head, Golgi complex gathering in front of nucleus forming acrosome, change in centriole as distal centriole from the axial filament, mitochondria form spiral sheath and middle piece.
• All these changes are aimed at keeping the spermatozoa small, light and motile. Oogenesis. The process of formation of the ovum from the ovum mother cells of the ovary. It is similar to spermatogenesis and completed in three phases viz. multiplicative phase, growth phase and maturation phase.

Similarities between Spermatogenesis and Oogenesis:

1. Both processes start with primordial germ cells derived from the germinal epithelium of gonads and occur inside the gonad.
2. Both the processes are completed in three phases i.e. multiplication, growth and maturation and show meiosis in the maturation phase.
3. Both processes produce haploid gametes.

Difference Between Spermatogenesis and Oogenesis:

NEET Biology Plant Growth and Development Structure Of Ovum

In all the animals, ova arc single-celled. The ovum is surrounded by a primary membrane called vitelline membrane which is produced after the release from the ovary, the secondary and tertiary membranes are secreted by the Graafian follicle or lining of the oviduct. These layers may be albuminous as in amphibians or may be porous, calcareous as in birds.

• Most animal eggs are spherical or oval, non-motile but on close examination it is noted that one pole is different from the other. The pole from which polar bodies are given off is called the animal pole while the opposite is termed as vegetal pole.
• Thus it is said to have polarity. Thus various cytoplasmic substances are unequally distributed along the axis. The nucleus, also called a germinal vesicle having a chromatin network is bounded by a nuclear membrane.
• It also contains prominent nucleolus. All animal eggs contain some reserve material to provide food called yolk. The cytoplasm of the ovum is called ooplasm. It lacks a centrosome but contains cortical granules derived from Golgi bodies in its peripheral region termed as cortex.

NEET Biology Plant Growth and Development Functions Of Ovum

1. It contributes female’s haploid set of chromosomes.
2. After fertilization, forms a zygote which gives rise to young animals by development.
3. Egg Membranes Protect The Developing Embryo.
4. The eggs are of different sizes. The smallest egg is that of the mouse (0.075 mm) find the largest is that of the ostrich bird (175 mm).

NEET Biology Plant Growth and Development Types Of Eggs

1. Types of eggs based on amount or yolk.

1. Alecvithal cups. Yolk absent c.g. Mctathcrian and cutlierian mammals.
2. Leithal eggs. Eggs contain yolk. They are of three types.
   1. Microlcoithal or olipolceithul Eggs: Microlcoithal Eggs contain very small amounts of yolk
      • Examples: Hydra, and sea urchin. Amphioxus, Tunicatcs.
   2. Mesolccithal Eggs: Mesolccithal Eggs contain a moderate amount of yolk
      • Examples: Earthworm, Dipnoi fishes, and amphibians.
   3. Macrolecithal or mepalecithal or polylccithal eggs: Macrolecithal Eggs contain large quantities of yolk
      • Examples: birds, fishes, reptiles, prototherian mammals and insects.

2. According to the distribution of yolk:

Eggs are of the following types

1. Home-lethal or Isolecithal eggs have evenly distributed yolk
   • Example: Porifers, Amphioxus, Echinodemiates.
2. Heterolecithal Or Anisolecithal Eggs:  Have Localized Yolk.
   • They Are Of The Following Types
     1. Telolecithal eggs: Telolecithal eggs in amphibians— yolk concentrated towards one side.
     2. Meiolecithal eggs: Meiolecithal eggs of birds and reptiles are large and yolk occupies the entire ooplasm.
     3. Centrolecithal eggs: Centrolecithal eggs in insects have yolk in the centre with cytoplasm forming a thin layer around.

3. Types Of Eggs According To Covering:

1. Cleidoic eggs. These eggs are fully laden with yolk and surrounded by albumen and water-proof shells made up of calcium
   • Example: Eggs of reptiles and birds.
2. Non-cleidoic eggs: Non-cleidoic eggs In such a shell is absent.

4. Types Of Eggs According To The Type Of Development:

1. Determinate or mosaic eggs. In such eggs, cleavage is of a determinate type and each part of the egg has a definite fate
   • Examples: Porifers, Platyhelminthes, annelids, arthropods and molluscs.
2. Indeterminate or regulative eggs. In this type, each early blastomere on separation from others may give rise to a complete embryo
   • Example: echinoderms and chordates.

Neet Biology Plant Growth And Development Pdf

NEET Biology Plant Growth and Development Egg Membranes Or Coats

Eggs possess unique coats beside the plasma membranes. They safeguard the eggs from predators and physical harm while supplying nourishment.

1. The primary membrane secreted by the egg is the vitelline membrane.
2. The secondary membrane is constituted by follicular cells of the ovary that encase the ovum. Chorion in the egg of Herdmania and zona pellucida in the mammalian egg.
3. Tertiary membrane produced by the oviduct’s gland. Jelly-like coating around the eggs of fish and amphibians, together with albumen, shell membranes, and the shell encasing the eggs of reptiles and birds.

NEET Biology Plant Growth and Development Structure Of Mammalian Sperm

Structure. A mammalian sperm is a minute, microscopic, flagellated and motile gamete with no nutritive material, protective envelopes and most cell organelles like ribosome, endoplasmic reticulum, etc. It is formed of four parts, each performing a specific function:

1. Head: The shape of the head varies in different mammals. It is generally oval and flat (in man, bull, rabbit). The head is formed of two parts :

• Acrosome (Gr. Akron = extremity; soma = body):  It is a small pointed structure present at the tip of the nucleus. It is formed from a part of the Golgi body of the spermatid. During the sperm entry, the acrosome secretes a lytic enzyme called hyaluronidase which helps in the penetration of the ovum.
• Nucleus: It is generally long, narrow and pointed but is flat and oval in human sperm. It is formed by condensation of nuclear chromatin of spermatid and loss of RNA, nucleolus and acidic proteins. Chemically, the nucleus is formed of deoxyribonucleoprotein (DNA + basic proteins). It is the carrier of genetic information.

The acrosome and anterior half of the nucleus are covered by a fibrillar sheath galea.

 2. Neck: It is the smallest part of spermatozoan and may be indistinct. It is formed of two centrioles perpendicular to each other and is formed from the centrosome of the spermatid.

• Each centriole is a microtubular triplet structure having a 9 + 0 arrangement. The proximal centriole lies in a depression in the posterior surface of the nucleus and is perpendicular to the main axis of the sperm. The distal centriole is along the longitudinal axis of the sperm.
• Centrioles form a spindle for the first cleavage of the zygote. Distal centriole acts as a basal body and gives rise to the axoneme of the sperm tail.

 3. Middle piece: It lies behind the neck and is cylindrical in human sperm.

• It is formed of a mitochondrial spiral called nebenkern around the proximal part of the axoneme.
• The middle piece is a powerhouse of sperm.
• The posterior half of the nucleus neck and middle piece of sperm is covered by a sheath called a manchette.
• Tail (Flagellum) It is the longest part of sperm. It is slender and tapering.

It comprises two parts: Central contractile and microtubular, axoneme or axial filament, and outer protoplasmic sheath.

• Axoneme is formed of 11 proteinous microtubules arranged in a 9 + 2 manner.
• Sometimes, a ring centriole may be present at the junction of the middle piece and flagellum.
• The tail shows lashing movements which provide a forward push to the sperm.

 4. Viability: It is the period up to which the sperm can fertilize an ovum. The viability of human sperm is about 24 hours.

NEET Biology Plant Growth and Development Fertilization

Fertilization. It is a fitness by which male and female gametes come close and fuse to form a zygote. The union of two gametes is termed syngamy and the intermixing of nuclei is amphimixis.

Steps Involved in fertilization are :

1. Encounter of spermatozoa and ova: It may occur inside the body (internal fertilization) or outside the body(external fertilization).
2. Capacitation and contact. Sperm (antifertilizin) and ovum (fertilizin) show fertilizin- antifertilizin reaction which is highly specific for a species.
3. Acrosome reaction and penetration: Golgi bodies of acrosome secrete enzymes.
   hyaluronidase which dissolves the membranes of the ovum so that materials of sperm can penetrate.
4. Activation of ovum: Immediately after the apical tip of the acrosomal tubule touches the egg plasma membrane, a fusion of both membranes takes place and a single continuous mosaic membrane is formed.

Thus plasma membrane of both gametes becomes continuous and forms a zygote. At this time certain changes occur in the cytoplasm of the egg which are collectively termed as activation of the ovum. It includes the following events.

1. Fertilization cone formation: Coming in contact with the acrosomal filament of spermatozoan, the cytoplasm of the egg bulges forward to produce a conical projection, the fertilization cone. It gradually engulfs the spermatozoan.
2. Cortical reactions and fertilization membrane formation: It may differ from one group of animals to the other, but, in most groups, it fundamentally culminates into the formation of a membrane, called fertilization membrane, outside the egg plasma membrane. This membrane blocks the entrance of late-arriving spermatozoa.
3. Metabolic activation: Following metabolic changes occur in the egg at the time of fertilization.
4. Changes in the plasma membrane: The permeability of the egg plasma membrane increases for the molecules of water, glycol and ions of K+, P04-3 etc. Its electrical potential becomes more positive in the beginning but more negative later on.
5. Ionic changes: The concentration of cations such as Na+, Ca++ and K+ changes during fertilization.
6. Changes in coenzyme: During fertilization, the inactive enzyme NAD-kinase becomes active and changes NAD into NADP and NADPH by phosphorylation.
7. Respiratory changes: Fertilization increases the rate of respiration in those eggs in which maturation is completed before fertilization (e.g., sea urchin) and decreases in those eggs in which fertilization occurs at the first maturation division (e.g., Chaetopterus).The respiratory rate increases for the release of more ATP.
8. Change in the rate of protein synthesis: During fertilization, the inhibitor enzymes are removed to initiate an action of protein synthesis.
9. Initiation of mitosis: It takes place due to the following agencies :

Immediately after fertilization, the rate of DNA synthesis increases many- folds and so also the uptake of cytoplasmic DNA Polymerase enzyme, which is required in the biosynthesis of DNA. The sperm introduces its centriole and by contributing a second centriole it initiates the formation of a spindle.

Plant Growth Regulators NEET Study Material

• Migration of pronucleus and amphimixis: To perform the act of amphimixis, the sperm nucleus has to perform two activities i.e., it has to become pronuclei and to migrate v from the site of penetration to the site of amphimixis. The fusion of male and female pronuclei is termed amphimixis.
  • Significance Of Fertilization:

1. 1. 1. It stimulates the egg to complete its maturation.
      2. The fusion of male and female pronuclei in fertilization restores the diploid number of chromosomes and activation of secondary oocytes results in a mature form of ovum. The ovum which is in a quiescent state with a low metabolic rate restores its normal metabolic activity.
      3. Fertilization initiates cleavage or segregation.
      4. The combination of the chromatin material from two different parents forms the physical basis of biparental inheritance and variation.
      5. The centriole of sperm initiates the first division of zygote timelines and further entry of sperm is checked by the fertility/action membrane.

Ovipary, Vivipnry and Ovovivipnry:

• Osipary: It is the development of an embryo inside its egg delivered outside the body. The fertilization may be external or internal.
• Vivipnry: It is the development of an embryo inside the uterus of a female connected using the placenta. The fertilization is internal. The female gives birth to the young one.
• Ovovivipnry: The phenomenon of retaining eggs and the development of embryos in the body till birth without forming any organic connection for obtaining extra nourishment i.e. no placenta formation. Fertilization is internal.

NEET Biology Plant Growth and DevelopmentCleavage

Cleavage: The series of divisions that occur inside the fertilized egg or zygote to transform it into a multicellular body called blastula is called cleavage. They produce blastomeres.

Characteristics of Cleavage:

1. Cleavage divisions are mitotic and occur one after the other. However, the rate depends upon species, amount of yolk and temperature.
2. During cleavage, growth does not take place and the size and volume of the embryo remain the same and the size of blastomeres is reduced.
3. The nuclear and cytoplasmic ratio becomes very low for the zygote and as a result cleavage increases.
4. During cleavage general shape of the embryo does not change.
5. All blastomeres divide simultaneously during early cleavage.
6. For rapid nuclear division, there is a great increase in the synthesis of DNA.
7. O2 consumption increases during cleavage.

The cleavage division differs from ordinary mitotic division in the following ways :

1. The cleavage division is not followed by the growth of daughter cells before they divide but during ordinary mitotic division, each division is followed by a growth of daughter cells before the next division starts.
2. The rate of cleavage depends in different species on temperature but during mitosis, it is not so.
3. During cleavage nuclear and cytoplasmic ratio is changed.
4. During cleavage, the blastomeres divide simultaneously but in ordinary mitosis all the daughter cells divide approximately at the same time.
5. The cleavage differs from ordinary mitosis of large-sized zygotes, and it is meant basically to reduce the size of blastomeres.

Pattern of Cleavage: Three common patterns of cleavage are radial, bilateral and spiral cleavage.

1. Radial cleavage: In radial cleavage, the successive cleavage planes cutting straight through the egg are at a right angle to one another. The resultant blastomeres become symmetrically, exposed around the animal-vegetal axis. Such type of cleavage occurs in sponges, coelenterates and a few molluscs.
2. Bilateral cleavage: In this pattern of cleavage, the blastomeres are so arranged that the right and left sides become apparent, e.g., Cephalopods, a few Echinoderms and Vertebrates.
3. Spiral cleavage:  In this pattern of cleavage, the furrows are so formed that the blastomeres are arranged in a spiral manner around the animal-vegetal axis e.g., Flatworms, annelids and molluscs.

Planes Of Cleavage During cleavage, different cleavage furrows may divide the egg into different planes.

1. Meridional plane. Cleavage furrow passes through the centre of the animal-vegetal axis and bisects both the poles of the egg. e.g., Frog.
2. Vertical plane. Cleavage furrow passes in a direction from the animal pole towards the vegetal pole. For. first cleavage furrows of Amin calva and chick.
3. Equatorial plane. It bisects the egg at right angles to the main axis and halfway between the animal and vegetal poles, e.g…… first cleavage plane of eggs of higher mammals.
4. Latitudinal plane. It is similar to equatorial, but it courses through the cytoplasm on either side of the equatorial plane, e.g., the third cleavage planes of Amphioxus and frog.

Neet Biology Plant Growth And Development Pdf

Types of cleavage: The amount and pattern of distribution of yolk determine the type of cleavage. It is of the following types :

• Holoblastic cleavage: In alecithal, isolecithal and slightly telolecithal eggs, the zygote and the blastomeres divide completely. It results in a cocloblastula i.e., a blastula with a central cavity called the blastocoel. Holoblastic cleavage is of two types
• Equal holoblastic cleavage: The cleavage produces approximately equal-sized blastomeres throughout. It occurs in alecithal eggs of rabbits and microlecithal eggs of sea squirts, amphioxus, marsupials and other placental mammals.

• Unequal holoblastic cleavage: This cleavage in later divisions gives rise to unequal blastomeres, small micromeres and large megameres. It occurs in telolecithal eggs of bony fishes and amphibians.
• Meroblastic Cleavage: In this type of cleavage, division occurs only in the small amount of metabolically active cytoplasm. The yolk remains undivided. It is found in macrolecithal eggs. It is of two types :
• Discoidal Cleavage: It is confined to the active cytoplasm located at the animal pole and occurs in isolecithal eggs of reptiles, birds and egg-laying mammals. It results in a blastula called a disco blastula.
• Superficial Cleavage: It occurs in the centrolecithal eggs of insects. The nucleus placed in the centre of the yolk divides repeatedly to form many daughter nuclei which migrate to the peripheral yolk-free cytoplasm. It then cleaves into many uninucleate blastomeres arranged around the yolk. It results in a superficial blastula consisting of single-layered epithelium enclosing yolk instead of blastocoel.

Significance of cleavage:

1. It produces a large number of cells from a single-celled zygote by repeated divisions and results in the formation of the embryo. , .•
2. It prepares the embryo for the migration of cells to their fixed position during gastrulation.
3. Preparation and initiation of the process of cell differentiation.

NEET Biology Plant Growth and Development Gastrulation

Gastrulation. It is a phase of embryonic development during which cell movements establish the three primary germinal layers and initiate morphogenesis.

The most important features of gastrulation in all animals are :

1. Complex but orderly and irreversible morphogenetic movements involving large masses.
2. The rhythm of cellular division is slowed down.
3. Growth if any is insignificant.
4. The nuclei become more active.
5. Formation of archenteron surrounded by endoderm.
6. The type of metabolism changes and the rate of oxidation is intensified.
7. Chemodifferentiation starts with the synthesis of new proteins.

• Epiboly: It involves stretching and spreading movements of ectoderm-forming cells to surround the embryo except at one pole called the blastopore.
• Emboly: It is the shifting or migration of the cells in such a way as to form internal layers of the mesoderm and endoderm of the embryo. It can occur by five methods.

1. 1. Invagination: It is the simplest type of emboly. In this method, the vegetal pole side of the blastula simply caves in or pushes into the interior e.g. Amphioxus and Invertebrates.
   2. Involution: It is the active rolling in of the endodermal and mesodermal cells from the surface to the interior through blastopore e.g., Frog.
   3. Ingression:  It is the proliferation of cells from the inner surface of the blastoderm into blastocoel which gets filled up with new cells and results in the formation of solid gastrula. The archenteron appears later on by splitting up of internal mass of cells. It may be unipolar as in Obelia or apolar as in Hydra.
   4. Delamination: Separation of sheets of cells to form two layers called epiblast and hypoblast e.g. chick, mammals.
   5. Convergence: It involves the migration of blastomeres from the outer surface towards the blastoporal lips.

NEET Biology Plant Growth and Development Fate Of There Germinallayers

Germinal layers:

Ectoderm, Mesoderm and Endoderm are the three primary germinal layers of the embryo as all the organs differentiate and develop from these layers.

NEET Biology Plant Growth and Development Morphogenesis And Nieekrentlation

Every living organism starts its life from a one-celled structure, a zygote, formed by a union of male and female gametes. From this one-celled stage, a multicellular stage is established by groups of processes of which morphogenesis and differentiation are outstanding.

Morphogenesis: It involves the formation of various structures in an individual organism resulting in the establishment of a young one.

There are two main processes of morphogenesis, namely growth and form:

1. Growth: Molecular growth increases the size of the individual cell. The mitotic division of cells, the most significant process of growth involves the increase in the number of cells and eventually the increase in bulk and complexity of the organism.
2. Form: The growth leads to the form of an individual plant or animal. The resultant of growth establishes various structures and organs. When a structure or an organ has reached its maximum limitation of size, further growth stops. The form is determined by polarity and symmetry. Polarity is of the three dimensions. In an organism one exerts dominance.

The head exerts dominance over the rest of the body. Due to polarity, there is a differentiation of anterior, posterior, right and left sides. Symmetry is the regularity of the arrangement of parts in an organism.

Differentiation: This involves the operational and functional components of development. The zygote divides repeatedly finally establishing millions of cells all having the same types of genes. Yet these cells differentiate into various organs. A group of cells at an early stage maintain certain functions while in the later part of life take up different functions.

Up to a stage the cells are capable of giving rise to any structure i.e. totipotent and after a time when a cell produces special types of cells, there cannot be any further transformation of the cell. The final stage reaches specialisation so that the cell is set apart to perform a definite function.

Plant Hormones And Growth Regulators Neet Notes

Cell differentiation may come about in three methods :

1. The developing differences among cells might be the result of progressive changes in gene action. Further, gene activity patterns might change differently in different cells resulting in differentiation.
2. While the gene action might remain constant, the cytoplasmic operations may become progressively altered.
3. Nuclear and cytoplasmic changes might occur reciprocally.
4. The differentiation may start from the molecular level leading to cellular differentiation.

NEET Biology Plant Growth and Development Formation Of Three Germinal Layers In Mammal

Development of three germinal layers. In viviparous mammals, fertilization occurs internally.

The subsequent processes transpire during the creation of the three germinal layers:

1. Cleavage:

The zygote undergoes holoblastic cleavage in the fallopian canal.

2. Morula:

A compact sphere of cells is generated through successive cleavage divisions.

3. Blastula:

(Blastodermic vesicle or Blastocyst) A chamber known as the blastocoel emerges in the developing embryo. The blastodermic vesicle is encased by an external cellular layer known as the trophoectoderm. The blastodermic vesicle exhibits an interior aggregation of cells resulting from differentiation. This aggregation of cells is referred to as the inner cell mass.

4. Gastrulation:

At this stage, the morphogenetic movements of the cells, such as epiboly and emboly, occur in small aggregates or sheets.

Consequently, three germinal layers are established:

1. Endoderm
2. Mesoderm
3. Ectoderm

1. Development of Endoderm:

Certain cells from the inner cell mass undergo delamination.

• Cells migrate in layers or aggregates within the blastocoel. These represent the prospective endodermal cells.
• These cells organize themselves as the second layer, situated between the inner and outer layers of the blastodermic vesicle.
• The blastocoel vanishes, and a new hollow emerges. The newly formed cavity is referred to as the archenteron.
• The residual mass of embryonal knob cells becomes convoluted and systematically organized to create an embryonic disc.

2. Formation or mesoderm:

The cells at the caudal end of the embryonic disc initiate proliferation and subsequently detach from the disc to produce mesoderm.

3. Development of ectoderm:

 Following the detachment of mesodermal cells from the embryonic disc, the remaining cells in the disc organize into a separate layer, forming the ectoderm.

NEET Biology Plant Growth and Development Placenta

• Placenta: A vascular organ that unites the foetus to the wall of the uterus in all mammals except marsupials and monotremes is called the placenta and its formation is plantation.
• Structure or Kpithelio-shoring placenta: Epitheliochorial is the simple and basic type of placenta formed in marsupials, pigs, horses, etc. In this case, some of the components are derived from the uterine wall of the mother while the other parts are derived from the foetus itself.

1. 1. Maternal components are (a) mucous membranes of the uterine wall (b) uterine connective tissue (maternal mesenchyme) (c) endothelium of maternal blood capillaries.
   2. Foetal components are A wall of foetal blood capillaries and foetal connective tissue. Foetal chorionic epithelium.
   3. Functions of the placenta:  The placenta serves primarily as an organ that permits the interchange of material earned in the blood of the mother and foetus. The main functions are :
   4. Nutrition: Supply of nutrient materials to the foetus. Respiration. Supply of 02 to the foetus and receive C02 back from it. Excretion. Fluid nitrogenous waste products escape through the placenta. Barrier. The placenta is a barrier-like semipermeable membrane.
   5. Storage: The placenta stores fat, glycogen and iron for the embryo before die formation of the liver. Hormonal function. The placenta secretes extra-ovarian hormones estrogen and progesterone in females during pregnancy that serve to maintain the foetus.

Classification of the placenta: The placenta is of five types depending upon the number of tissue layers that separate the foetal blood from maternal blood.

Epitheliochorial placenta (all six layers) e.g. horse, pig and donkeySyndesmochorial placenta (five layers present, uterine epithelium eroded e.g., cow, goat, sheep Endotheliochorial placenta (four layers present-uterine epithelium and connective tissue eroded) e.g. dog and catHaemochorial placenta (three layers present-material three layers eroded) e.g, primates including human andHaemoendothelial placenta (all the maternal and two foetal tissue layers eroded) e.g. rodents and rabbits.

Previous Year Neet Questions On Plant Growth

Types of placentae according to the distribution of villi on chorion.

1. Diffuse placenta: Chorionic villi remain scattered all over the surface of the chorion e.g., pig, horse, lemur.
2. Cotyledonary placenta: The villi are found in groups or patches e.g. cattle, sheep, deer
3. Zonary placenta: The villi are developed in the form of a belt or girdle e.g. cats, dogs Discoidal placenta. The villi continue developing only on one side e.g. mouse, rat, human, monkey.
4. The placenta is of three types, viz. Allantoic, yolk sac and chorionic placenta: about the foetal membrane that takes part in its formation.

NEET Biology Plant Growth and Development Vitellogenesis

The synthesis of yolk is termed vitellogenesis. Recent investigations have revealed that yolk is not necessarily synthesized in oocytes but produced elsewhere in some extra ovarian tissue such as fat bodies in insects.

• In fishes, amphibians and also in gastropod molluscs, its synthesis takes place inside modified mitochondria.
• In other vertebrates, yolk is produced in liver cells. It is transported to the ovarian follicle by blood in the soluble form. From these cells of the follicle, the oocyte takes the yolk by pinocytosis.
• The Golgi complex and endoplasmic reticulum of oocytes transfer these yolk components to modified mitochondria and convert them into insoluble forms.

1. 1. Composition of yolk: The yolk is the reserve food material in the egg. It is composed of proteins, phospholipids and neutral fats. The yolk may be a protein yolk if it contains mainly protein. If the yolk consists mainly of phospholipids, neutral fats and small fats, it is termed a fatty yolk. Both kinds of yolk are present side by side in the eggs but protein yolk is the main constituent of many invertebrates and chordates.
   2. Utilization of yolk: In the isolecithal eggs Example: frog) the yolk gets distributed to all the daughter cells at the time of cleavage. However, at later stages, some cells may have more yolk due to unequal division. The yolk is broken down into simpler substances and utilized in the synthesis of new protoplasmic constituents.

In the acrolectal egg of birds, the yolk is absorbed by diffusion in the early stages. Later on, a yolk sac develops around the yolk mass from mesoderm and endoderm. Blood vessels called vitelline arteries and veins connect the yolk sac with the heart. The enzymes from the yolk sac digest the yolk into soluble form, which is then taken to the heart and vitelline veins and then distributed to all parts of the developing embryo.

NEET Biology Plant Growth and Development Hereditary Defects

• Teratology: It is the branch of developmental biology which deals with the study of abnormal development during embryogenesis. The ways and means by which abnormal developments occur during embryogenesis are called teratogenesis.
• List of hereditary defects, Colour blindness harelip (Cleft plate Clubfoot Hole in the heartAbsence of hands, feet, arms or legs (Meromelia) Right half body normal and left like dwarf (Achondroplasia) Mongolism Phenylketonuria Albinism Alkaptonuria Haemophilia Polydactyly Cat cry syndrome (at) Turner’s syndrome and Klinefelter syndrome.
• Identical twins: The twins are of the same sex and are identical in all respects including appearance, size and behaviour.
  The identical twins are monozygotic because they develop as a result of fertilization of the single ovum by a single sperm but the zygote divides into two halves and each half gives rise to a child. Each gets attached to the same placenta.
• Fraternal twins: The fraternal twins are dizygotic as they are produced due to the fertilization of two different eggs. They may or may not belong to the same sex. They may or may not resemble each other.
• Normally the ovaries release a single egg at a time or if two eggs are released both may be fertilized and then may develop into two separate individuals, thus fraternal twins develop from two different zygotes, hence termed dizygotic twins. They are connected to the uterine wall by a separate placenta.
• Conjoined twins: Twins are generally normal babies, but some twins may be abnormal in shape, structure or development. Some twins may be fused wholly or in part, such fused twins are called conjoined twins. The degree of union may be slight or extensive. Union is by heads and upper trunk.

Previous Year Neet Questions On Plant Growth

NEET Biology Plant Growth and Development Important Notes

1. Spermiogenesis: The process of conversion of a spermatid into a functional spermatozoan by the process of differentiation of specialization is called spermiogenesis or spermioteliosis.
2. Sertoli cells: These are indifferent cells situated in the lining of seminiferous tubules which provide nourishment to the differentiating spermatozoa. Sperms’s head is kept embedded in Sertoli cells for this purpose.
3. External fertilization: The fusion of male and female gametes takes place outside the body of a female animal.
4. Internal fertilization: The fusion of male and female gametes takes place inside the body of a female animal.
5. Amnion: A thin extra-embryonic membrane forms a closed sac around the embryo in birds, reptiles and mammals.
6. Amniota: A collective term for the reptiles, birds and mammals, all of which have an amnion.
7. Anamniote: Any animal of which the amnion is absent during embryonic development.
8. Amniotic fluid: A substance that fills the amnion to protect the embryo from shock and industry.
9. Amniocentesis: A procedure during pregnancy by which the abdominal wall and foetal membrane are punctured with a cannula to withdraw amniotic fluid.
10. Amphimixis: The union of nuclei of egg and sperm in sexual reproduction.
11. Allantois: A fluid-filled, sac-like extraembryonic membrane lying between the chorion and amnion of reptiles, birds and mammals.
12. Allantochorion: The extraembryonic membrane is formed by the fusion of the outer wall of allantois and with the primitive chorion.
13. Chemo-difTerentiation: It is the chemical differentiation of cells of the embryo during development.
14. Cyto-differences: It is the differentiation of cells ol ciuluyo dining development.
15. no-dinViviilintlon: It location of the tissue mill also ballots ns histogenesis.
16. Orgnn-dinVivntlntlon: It is tot million of guns limit the embryo.
17. Kmhnoule Murillo: The supply of required materials which are essential for the synthesis of unit ami and other compounds ami for the production of energy during the development of the embryo is called embryonic nutrition. The materials required are amino acids, minerals and oxygen.
18. Diapause: The sexual rest period in insects is called diapause.
19. Kmlometrium: Glandular mucous membrane lining of the uterus.
20. Genome: The set of all different chromosomes found in each nucleus of a given species. A haploid nucleus has one genome.
21. Germinal vesicle: Nucleus of the animal oocyte during the period of cytoplasmic growth.
22. Gestation period: Length of time from conception to birth in viviparous animals.
23. lactation: Production of milk.
24. Monoccious:fUiscxual or hermaphrodite).
25. Mullerian Duct: Oviduct of female gnathostome vertebrate.
26. Neoteny: Persistence of the form of a larva or any other stage (larva becomes sexually matured.)
    • Example: Axolotl Larva of Salamander in Amphibians
27. Nidicolous birds: Those which hatch undeveloped.
28. Nymph: Young states of exopterygote insect.
29. Oxytocin: A hormone secreted by the posterior lobe of the pituitary gland which causes labour pains (contraction of uterine muscles.).
30. Secondary sexual characters: A characteristic of animals which differ between the two sexes.
31. Seminal vesicles: Organs which store sperm in males (cf).
32. Spermatheca. Organs which store sperm in female ($).
33. Syngamy:Union of gametes is termed syngamy.
34. Testosterone: A principal male hormone.
35. Urethra: Duct leading from the urinary bladder of mammals to the exterior.
36. Uterus masculinus: A sac-like structure dorsal to the bladder in male mammals.
37. Vitelline membrane:  Primary egg membrane secreted by the egg.
38. Yolk plugs: A mass of macromeres which closes the blastopore in the developing embryo

• Colostrum. The first milk which comes out from the mother’s mammary glands just after childbirth is known as colostrum. It is rich in calories and proteins. It contains antibodies.
• On average human ejaculate of 3 – 4 ml of semen contains 80-100 million spermatozoa.
• Virus infection of the mother e.g. by the rubella (German measles) virus or exposure to certain chemicals may cause malformation in the developing embryo. Such agents are called teratogens.  All the systems in a developing foetus are formed by the three months of pregnancy.
• cv During further development after three months, there was growth and a few minor structural modifications. Extra-embryonic membranes include the yolk sac, amnion, chorion and allantois.
• Yolk sac is also found in like certain fishes Example: Scoliodon), bony fishes and a few amphibians
• Example: Necturus having an egg.
• Amnion, chorion and allantois are formed only in am- niote embryos as their development occurs on land either inside the egg or in the uterus of the mother.
• These are not formed in amniotes as their development occurs in water so there is no problem of desiccation, supply of oxygen and removal of wastes. c& Amnion is an innermost embryonic membrane and never participates in placenta formation.
• c& Chorion is an outermost embryonic membrane and always participates in placenta formation.
• Polarity. The existence of a definite axis in the egg and the embryo is called polarity. In the egg, polarity is indicated by the position of the nucleus and the yolk.
• Inducers (Organizers). The cells that induce or control die developmental fate of the neighbouring cells in an embryo are called inducers or organizers.
  c& Inductors. These are the chemicals which the inducers release to guide the fate of the adjacent cells.

NEET Biology Plant Growth and Development Quanta To memory

• Identical twins:  Twins are the term used to describe the delivery of two or more infants in a single birth. These may be identical twins, monozygotic twins, fraternal, dizygotic, or non-identical twins.
• Siamese siblings: Conjoined twins are joined at the pelvis, chest, kick, and face. These are monozygotic and have been surgically separated for the first time in Siam.
• In the process of frog oogenesis, a single oogonium generates a single ovum and only two polar bodies.
• In mammals, a fertilization membrane is not formed; however, die enzymes that are released following the formation of the zona pellucid neutralize sperm receptors, preventing any additional sperm from binding to them.
• Transformation: Metamorphosis is the term used to describe the process by which a juvenile individual undergoes a transformation into a morphologically and physiologically distinct adult. There are two varieties of it.
• Metamorphosis that is retrogressive: The transformation of an advanced larva into a degenerate adult, such as Merdmania. Sacculina.
• Metamorphosis in progress: When a simplified larva transitions into an advanced adult, such as a frog.
• Martinis are complimentary: A male and a female heifer that were sexually underdeveloped were united.
• Fate diagram: Diagram illustrating presumptive or potential regions on the blastula’s surface.
• This is accomplished through the utilization of specific essential stains, including neutral red, Nile blue sulphate, and Bismarck brown. It was initially prepared by W. Vogt in 1929.

Stages Of Embryonic Development in Human

NEET Biology Growth, Repair Regeneration Ageing And Death Multiple Choice Questions

Question 1. The convention of a specialized cell into an unspecialized embryonic type of evil is referred to as :

1. Differentiation
2. Dedifferentiation
3. Transformation
4. Convergence.

Answer: 2. Dedifferentiation

Question 2. Growth of a cell occurs during :

1. M-phase
2. interphase
3. Both i and 2
4. Replication.

Answer: 2. interphase

Question 3. Which one of the following can regenerate its limb if lasts by accident?

1. Crab
2. Adult frog
3. Salamander
4. Tadpole.

Answer: 3. Salamander

Question 4. Regeneration in which animal was discovered for the first time?

1. Sycon
2. Hydra
3. Planaria
4. Phererima.

Answer: 2. Hydra

NEET Biology Important MCQs

Question 5. Which one of the following organs has a high degree of power of regeneration?

1. Lungs
2. Kidney
3. L4er
4. Spinal cord.

Answer: 3.L4er

Question 6. Ageing is caused by the disappearance of :

1. Thyroid
2. Thymus
3. Pituitary’
4. Parathyroid.

Answer: 2. Thymus

Question 7. The number of renal glomeruli is reduced to about half in human beings:

1. 50 Yrs. old
2. 70 yrs. old
3. 60 yrs. old
4. 75 yrs. old.

Answer: 4. 75 yrs. old.

Question 8. Senescence means :

1. The period of the life cycle when an animal takes its first breath
2. The time of life cycle when an animal becomes sexually mature
3. The process of growth of body size by mitotic division
4. The process of growing old.

Answer: 4. The process of growing old.

Question 9. It has been observed among kidney donors that the only kidney in the body enlarges and performs the function of a lost kidney. This phenomenon is called :

1. Senescence
2. De-differentiation of kidney
3. Blastema
4. Compensatory’ hypertrophy.

Answer: 3. Compensatory’ hypertrophy.

Human Ageing NEET Questions

Question 10.Protein which plays a significant role in ageing is :

1. Elastin
2. Actin
3. Myosin
4. Collagen.

Answer: 4. Collagen.

Question 11. When the reserve food material is utilized in the body, the process is called :

1. Anabolism
2. Degrowth
3. Ageing
4. Growth.

Answer: 2. Degrowth

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 12. The branch of developmental biology which deals with the study of ageing is called :

1. Ornithology
2. ichthyology
3. Gerontology
4. Histology.

Answer: 3. Gerontology

Question 13. During differentiation, cells with the same DNA :

1. Develop similarly
2. D4ide at equal rates
3. Contain different genes
4. Transcribe different genes.

Answer: 4. Transcribe different genes.

Question 14. Capacity for regeneration is maximum in :

1. Sponges
2. Hydra
3. Earthworm
4. Tadpole.

Answer: 2. Hydra

NEET Previous Year Questions On Ageing

Question 15. The gland that shows atrophy and degenerates with the advancement of age and disappears by middle age is :

1. Thyroid
2. Pituitary
3. Prostate
4. Thymus.

Answer: 4. Thymus

Question 16. The life span of an organism depends on the rate of:

1. Growth
2. Regeneration
3. Repair
4. Ageing.

Answer: 4. Ageing.

Question 17. Growth of higher animal body takes place by the addition of:

1. Protoplasmic substances
2. Apoplasmatic substances
3. Both  1 and 2
4. None of the tires above.

Answer: 3. Both 1 and 2

Question 18. Which of the following shows autotomy?

1. Starfish
2. Prawn
3. Wall lizard
4. All of above

Answer: 4. All of the above

Question 19. A lost leg cannot be regenerated by :

1. Salamander
2. Tadpole larva
3. Crab
4. Adult frog.

Answer: 4. Adult frog.

Question 20. When the whole body is formed from a body segment, it is called :

1. Morphallaxis
2. Epimorphosis
3. Parthenogenesis
4. Epigenesis.

Answer:1. Morphallaxis

NEET Previous Year Questions On Ageing

Question 21. The Father of gerontology is :

1. Korenchevsky
2. Hayflick
3. Trembley
4. Sachs.

Answer: 1. Korenchevsky

Question 22. A bud-like structure formed at the end of the cut limb of a salamander is:

1. Blastula
2. Blastema
3. Blastumela
4. Plasma.

Answer: 2. Blastema

Ageing Process NEET Important Questions

Question 23. Parafunctional development occurs in :

1. Embryo
2. Foetus
3. infant
4. Adult.

Answer: 1. Embryo

Question 24. Reserve cells in the human body occur in the:

1. Germinal epithelium
2. Bone marrow
3. Stratum germinat4um
4. All the above.

Answer: 4. All the above.

NEET Biology Basic Features Of Development Multiple Choice Questions.

Question 1. Among the following who is regarded to be the founder of modem mixology?

1. Aristotle
2. Newport
3. Von Baer
4. Spallanzani.

Answer: 3. Von Baer

Question 2. Olhpungs sexual reproduction resembles their parents :

1. Structurally hut not luitctlonnlly
2. Neither structurally nor functionally
3. Both structurally and functionally
4. Only functionally but not structurally.

Answer: 3. Both structurally and functionally

Question 3. Out of these scientists who discovered spermatozoa and called them animalcules?

1. Hippocrates
2. Aristotle
3. Leeuwenhoek
4. Herlwig.

Answer: 3.Leeuwenhoek

NEET Plant Physiology MCQs

Question 4. The study of the development of an organism is termed :

1. Ecology
2. Euphonies
3. Embryology
4. Eugenics.

Answer: 3. Embryology

Question5.Of the following animals which produces the smallest egg?

1. Hummingbird
2. Salmon
3. Blue whale
4. American toad.

Answer: 3. Blue whale

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 6. What gives rise to the gametes in multicellular animals?

1. Zygote
2. Ectoderm
3. Mesoderm
4. Germ cells.

Answer: 4. Germ cells.

Question 7. Which type of cell division takes place in germ cells during gametogenesis?

1. Asexual
2. Meiotic
3. Mitotic
4. Both and.

Answer: 4. Both 1 and 2.

Question 8. Primitive germ cells or spermatogonia are located in the :

1. Basement membrane
2. Layer of germinal epithelium
3. Fibroelastic epithelium
4. Stratified epithelium.

Answer: 4. Stratified epithelium.

NEET Plant Physiology MCQs

Question 9. Spermiogenesis is characterized by :

1. Removal of water from the head of the spermatid
2. Formation of the spiral body of mitochondria
3. Formation of acrosome on file top of nucleus
4. All of the above.

Answer: 4. All of the above.

Question 10. Conversion of immotile spermatids into motile spermatozoa is called :

1. Spermiogenesis
2. Hydrolysis
3. Motilism
4. Transformation.

Answer: 1.Spermiogenesis

Question 11. The reproduction begins with the formation of:

1. Ova
2. Bud
3. Sperm
4. Reproductive unit.

Answer: 4. Reproductive unit.

Question 12. During spermatogenesis, meiosis occurs in :

1. Sperm mother cell
2. primary spermatocyte
3. secondary spermatocyte
4. None of the above.

Answer: 4. None of the above.

Question 13. Prlmiliy spemmlocyle irfrn to :

1. Sperm he fore limit nutrition division
2. Sperm nitre the first nutrition division
3. Spermatogonium which ceases divisions and starts growing
4. Primordial sex cell.

Answer: 3. Spermatogonium which ceases divisions and starts growing

Question 14.From one sperm mother cell (primary spermatocyte), the number of sperms produced arc :

1. 4
2. 1
3. 8
4. 16.

Answer: 1.4

Question 15. The spiral sheath of the sperm is formed by :

1. Nucleus
2. Centriole
3. Golgi bodies
4. Mitochondria.

Answer: 4. Mitochondria.

NEET Plant Growth And Development Notes

Question 16. Which of the following does not possess flagellum in the sperm?

1. Frog
2. Roundworm
3. Man
4. Sea urchin.

Answer: 2. Roundworm

Question 17. The middle piece of the sperm consists of a compact mass of:

1. Mitochondria
2. Endoplasmic reticulum
3. Golgi bodies
4. Lysosomes.

Answer: 1. Mitochondria

Question 18. A cell formed from cleavage is :

1. Morula
2. Blastomere
3. Blastopore
4. Blastula.

Answer: 4. Blastula.

Question 19. The diploid number of chromosomes is restored by :

1. Fertilization
2. Maturation
3. Reduction division
4. Spermatogenesis.

Answer: 1. Fertilization

Question 20. The head of sperm consists of:

1. Acrosome
2. Acrosome and nucleus
3. Nucleus
4. Mitochondria.

Answer: 2. Acrosome and nucleus

NEET Plant Growth And Development Notes

Question 21. Dysmenorrhoea a painful menstruation, is caused by :

1. uterine tumours
2. ovarian cysts
3. Pelvic inflammation
4. All of the above.

Answer: 4. All of the above.

Question 22. The sperms produce some enzymes known as “Spermiolysins”. These help in :

1. Viability by sperms
2. Penetration by sperms
3. Movement of sperms
4. Spermatogenesis.

Answer: 2. Penetration by Sperms

Questions Question 23. Fertilizing is emitted from :

1. Polar body
2. Nature ova
3. Immature egg
4. Sperms.

Answer: 2. Nature ova

Plant Growth And Development MCQs NEET

Question 24. The process of spermatogenesis is under the regulatory influence of:

1. Oxytocin
2. Vasopressin
3. Follicle-stimulating hormone
4. Luteotrophic hormone.

Answer: 3. Follicle-stimulating hormone

Question 25. In frogs lie sperm ceased Imm the testis takes (lie the following milk’ to teaeli urinogenital line :

1. Vasa efferentia. Bidder’s canal,nutrition nephrostome.
2. vasa efferentia, Bidder’s canal and nephrostome
3. Vasa differentia. Bidder’s canal and nephrostome
4. Vasa efferentia. Bidder’s canal and collecting tubule.

Answer: 4. Vasa efferentia. Bidder’s canal and collecting tubule.

Question 26. Oogenesis in Irog lakes place in :

1. Interstitial cells in the ovary
2. Germinal epithelium in the ovary
3. Epithelium in the ovi sac
4. Squamous epithelial cells in the ovary.

Answer: 4. Squamous epithelial cells in the ovary.

Question 27. Oogenesis can be explained as :

1. The process of formation of eggs
2. Growth
3. Ejaculation
4. None of the above.

Answer: 1. The process of formation of eggs

Plant Growth And Development MCQs NEET

Question 28. The process which helps in the formation and maturation of ova is :

1. Morphogenesis
2. Organogenesis
3. Oogenesis
4. Spermatogenesis.

Answer: 3. Oogenesis

Question 29. Vitelline membrane is secreted by and surrounds the :

1. Ova or eggs
2. oogonium
3. Spermatids
4. Oocyte.

Answer: 1. Ova or eggs

Questions Question 30. Albumen around the egg of the frog is secreted by :

1. Egg itself
2. Follicle cells
3. Oviduct
4. None of the above.

Answer: 3. Oviduct

Question 31. The vitelline membrane of a frog’s egg is :

1. Primary membrane
2. Secondary membrane
3. Tertiary membrane
4. None of the above.

Answer: 1. Primary membrane

MCQs On Plant Growth For NEET

Question 32. An egg containing very little of yolk is called :

1. Microlecithal
2. Meiolecithal
3. Telolecithal
4. None of the above.

Answer: 1. Microlecithal

Question 33. Insect egg in which yolk is present in the centre is called as :

1. Centrolecithal egg
2. Hexapoda egg
3. Megalecithal egg
4. Telolecithal.

Answer: 1. Centrolecithal egg

Question 34. A jelly layer of the frog is :

1. Primary membrane
2. Secondary membrane
3. Secreted by the egg
4. Tertiary membrane.

Answer: 4. Tertiary membrane.

Question 35. The animal pole of a frog’s egg can be distinguished by :

1. Position of polar body
2. Eccentric nucleus and pigmentation
3. Eccentric nucleus and yolk
4. None of the above.

Answer: 2. Eccentric nucleus and pigmentation

Question 36. The active cytoplasm and nucleus of a frog’s egg are confined to :

1. Vegetal pole
2. Animal pole
3. Displaced slightly towards the animal pole
4. Eccentrically between the two.

Answer: 2. Animal pole

MCQs On Plant Growth For NEET

Questions Question 37. The Yolk of an egg in vertebrates is formed in the:

1. Ovum
2. Lungs
3. Liver
4. Kidney.

Answer: 3. Liver

Question 38. Antifertilizins tire contained in :

1. Spermatozoa
2. Ovary
3. Testis
4. Germinal epithelium.

Answer: 1. Spermatozoa

Question 39. A human embryo begins to implant when it is blastocyst or has approximately 100 cells. How old is the embryo at this time?

1. 12 hours
2. 2 days
3. 6 days
4. 2 weeks.

Answer: 3. 6 days

Question 40. Polar bodies are the products of:

1. Supernumerary sperm
2. Unequal division of the nucleus
3. Unequal division of cytoplasm
4. Cell excretion.

Answer: 3. Unequal division of cytoplasm

Question 41. Eggs which have a sufficiently large amount of yolk and are large-sized are called :

1. Oligolecithal
2. Isolecithal
3. Polylecithal
4. Telolecithal.

Answer: 3.Polylecithal

Question 42. In the egg of a bird, the shell and shell membrane are :

1. Porous to 02 and C02
2. Porous to air only
3. Porous to water only
4. Non-permeable.

Answer: 1. Porous to 02 and C02

Question 43. The egg of a frog as it is laid in water is a :

1. Nature ovum
2. Secondary oocyte
3. Fertilized egg
4. Primary oocyte.

Answer: 4. Primary oocyte.

Growth And Development In Plants MCQs

Question 44. Grey crescent is present in :

1. Fertilized egg of frog
2. Eye of frog
3. Brain of rabbit
4. Eye of cockroach.

Answer: 1. Fertilized egg of frog

Question 45. Microlecithal eggs are those which have :

1. A large amount of yolk
2. The average amount of yolk
3. Gastrulation
4. No yolk.

Answer: 3. Gastrulation

Question 46. The phase of embryonic development during which cell movement establishes the three primary germ layers is called :

1. Gastrulation
2. Blastulation
3. Cleavage
4. Inundation.

Answer: 1. Gastrulation

Question 47. Eggs which have no yolk or an extremely small amount of yolk are called :

1. Alecithal
2. Polylecithal
3. Telolecithal
4. Mesolecithal.

Answer: 1. Alecithal

Question 48. Fertilization :

1. Activates the egg
2. Brings fusion of two haploid nuclei
3. Both and
4. None of the above.

Answer: 3. Both and

Question 49. The intermixing of two nuclei and later two gizmos”. K known av

1. Syngamy
2. Fertilization
3. Amphimixis
4. None of the above.

Answer: 2. Fertilization

Growth And Development In Plants MCQs

Question 50. When the two gametes unite to form a zygote, it won’t:

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

Answer: 2. Diploid

Question 51. Arrange in the correct sequence the stages of development of the fertilized ovum i.c. blaslula zygote (e) gastnda momla :

1. a. c. b. d
2. b, a, c. d
3. b. d. a. c
4. d. b. a, c.

Answer: 3. b. d. a. c

Question 52. After the sperm enters the egg, the cytoplasm rotates through the:

1. 180°
2. 90°
3. 75°
4. 60°.

Answer: 1. 180°

Question 53. The process that sets in after fertilization is known as:

1. Cleavage
2. Blastulation
3. Gastrulation
4. Neurulation.

Answer: 1. Cleavage

Question 54. Substances released by mature eggs of animals to agglutinate sperms are:

1. Antifertilizin
2. Sperm lysin
3. Fertilizin
4. Cortical granules.

Answer: 3. Fertilizin

NEET Plant Physiology MCQs

Question 55. In teleosts, reptiles and birds, the cleavage pattern is :

1. Equal holoblastic
2. Unequal holoblastic
3. Incomplete meroblastic
4. Complete meroblastic.

Answer: 3. Incomplete meroblastic

Question 56. Cleavage is a type of division in which the fertilized egg?

1. Divides repeatedly without growth
2. Divides repeatedly and grows
3. Does not divide, simply grows
4. None of the above.

Answer: 1. Divides repeatedly without growth

Question 57. Cleavage leads to formation of :

1. Blastula
2. Egg
3. Gamete
4. zygote.

Answer: 1.Blastula

Question 58. The ratio of nucleus to cytoplasm at the beginning of cleavage is :

1. very low
2. very high
3. Normal
4. A bit higher than normal.

Answer: 1. very low

Question 59. Grey crescent is the area :

1. At the point of entry of sperm into the ovum
2. Just opposite the site of entry of sperm into the ovum
3. At the animal pole
4. In the middle between the animal and vegetal pole.

Answer: 1. At the point of entry of sperm into the ovum

NEET Plant Physiology MCQs

Question 60. The development of the zygote into an embryo is called as :

1. Embryogenesis
2. Organogenesis
3. Blastogenesis
4. Gametogenesis.

Answer: 1. Embryogenesis

Question 61. When eggs are completely divided, during cleavage, into blastomeres, the type of cleavage is known as :

1. Holoblastic
2. Megaloblastic
3. Meroblastic
4. None of the above.

Answer: 1. Holoblastic

Question 62. When cleavage luirmv pimc’t through the centre of the animal vegetal axis and hlsccl’i both the poles of the egg, the plane of cleavage is called :

1. Meridional
2. Equatorial
3. Vertical
4. Latitudinal.

Answer: 1. Meridional

Question 63. Spiral cleavage is found in :

1. Synapla
2. Amphibia
3. Nematoda, nnnclida and rotifera etc.
4. None of the above.

Answer: 3. Nematoda, nuclide rotifera etc.

Question 64. Which of these is the first phase of development during embryogenesis?

1. Differentiation
2. Organogenesis
3. Fertilization
4. Gastrulation.

Answer: 3. Fertilization

Question 65. After the main organs of the embryo and its embryonic membranes are formed, then the mammalian embryo is called :

1. Foetus
2. Morula
3. Gastrula
4. Endometrium.

Answer: 1. Foetus

NEET Plant Physiology MCQs

Question 66. The external stimulus which induces cleavage in an unfertilized ovum is called :

1. Fertilization
2. Chemotaxis
3. Paedogenesis
4. Neoteny.

Answer: 1. Fertilization

Question 67. In birds, cleavage is:

1. Discoidal
2. Superficial
3. Complete
4. Absent.

Answer: 1. Discoidal

Question 68. An avian blastula is called :

1. Blastocyst
2. Trophoblastic
3. Blastoderm
4. Foetal blastula.

Answer: 1. Blastocyst

Question 69. A zygote develops into a mature organism by undergoing :

1. Cleavage
2. Fertilization
3. Conjugation
4. Reduction division.

Answer: 1. Cleavage

Question 70. The solid ball of cells produced during cleavage is :

1. Gastrula
2. Blastula
3. Morula
4. Polar body.

Answer: 3. Morula

NEET Plant Growth And Development Notes

Question 71. Clustering is a protein present in the sperm head of some :

1. Salmon fish
2. Birds
3. Mammals
4. Frog.

Answer: 1. Salmon fish

Question 72. Blastodisc or germinal disc refers to the protoplasm of the egg, this is restricted to a small area in :

1. Amphibian egg
2. Avian egg
3. Ascidian egg
4. Mammalian egg.

Answer: 4. Mammalian egg.

Question 73. The type of cleavage shown by centrolecithal eggs is :

1. Superficial meroblastic
2. Discoidal meroblastic
3. Holoblastic cleavage
4. Both and.

Answer: 1. Superficial meroblastic

Question 74. When the cleavage furrow extends from the animal pole to the vegetal pole and does not bisect the egg equally into two blastomeres, the plane of cleavage is :

1. Meridional
2. Equatorial
3. Latitudinal
4. vertical.

Answer: 4. vertical.

Question 75. During the development of the human foetus, the blood tissue ‘ starts developing in the 15th week. It starts with the development of :

1. Blood plasma
2. Blood platelets
3. RBC and WBC
4. Blood islands.

Answer: 4. Blood islands.

Question 76. The third cleavage in a frog’s egg. is :

1. Latitudinal
2. Horizontal Equtilorial
3. Meridional
4. Horizontal.

Answer: 1. Latitudinal

NEET Plant Growth And Development Notes

Question 77. As a result of cleavages, if blastomeres are symmetrically placed mound the polar axis, the type of cleavage is known as :

1. Spiral
2. Discoidal
3. TO biradial
4. Radial.

Answer: 4. Radial.

Question 78. Oblique cleavages in egg produce a symmetry known as:

1. Spiral
2. Biradial
3. Bilateral
4. Radial.

Answer: 3. Bilateral

Question 79. In frog’s egg symmetry wise the type of cleavage is :

1. Siradial
2. Spiral
3. Bilateral
4. None of the above.

Answer: 1. Siradial

Class 11 Biology MCQ  Question 8O. Gastrulation in ampliioxus is by :

1. Convergence
2. Emboly and epiboly
3. Divergence
4. Epiboly and involution.

Answer: 2. Emboly and epiboly

Question 81. Complete holoblastic cleavage occurs in :

1. Centrolecilhal eggs
2. Telolecithal eggs
3. Macrolecithal eggs
4. Microlecithal eggs.

Answer: 4. Microlecithal eggs.

Question 82. Superficial cleavage occurs in the egg of:

1. Toad
2. Frog
3. Hen
4. Cockroach.

Answer: 3. Hen

NEET Plant Growth And Development Notes

Question 83. Spiral cleavage occurs in :

1. Ampliioxus
2. Insects
3. Molluscs
4. Reptiles.

Answer: 3. Molluscs

Question 84. Discoidal meroblastic cleavage is characteristic of:

1. Insects
2. Mammals
3. Amphibians
4. Birds.

Answer: 4. Birds.

Question 85. The blastodisc of a chicken egg is equivalent to:

1. Egg nucleus
2. zygote
3. Blastula
4. Morula.

Answer: 3. Blastula

Question 86. How many cleavages are completed in the celled stage of a frog’s egg?

1. Three
2. Five
3. Eight
4. Sixteen.

Answer: 2. Five

Question 87. In frogs, micromeres contain :

1. A large amount of yolk
2. The normal amount of yolk
3. A little amount of yolk
4. No yolk.

Answer: 4.No yolk.

Plant Growth And Development MCQs NEET

Question 88. In an isolecithal egg, one would expect :

1. Meroblastic cleavage
2. Unequal holoblastic cleavage
3. Equal holoblastic cleavage
4. None of The above.

Answer: 1. Meroblastic cleavage

Question 89. A ball of cells with an enteric cavity is called :

gastrula

Iliscoblastula

Morula

Gaslrula.

Answer: 4. Gaslrula.

Question 90. The unit cell of the blastula is:

1. Micromerc
2. Mcgamerc
3. Blastomere
4. None of the above.

Answer: 3. Blastomere

Question 91. The blastula in mammals is referred to as :

1. Blastoderm
2. Blastodisc
3. Blastocyst
4. Coeloblastula.

Answer: 3. Blastocyst

Question 92. The primary organizer in Frog is :

1. yolk plug
2. ventral lip of blastopore
3. The dorsal lip of the blastopore
4. Lateral lip of blastopore.

Answer: 3. Dorsal lip of blastopore

Question 93. Blastopore is an aperture found in :

1. Blastula
2. Morula
3. Gastrula
4. Neurula.

Answer: 3. Gastrula

Question 94. In frogs, presumptive ectodermal cells show :

1. Emboly
2. Invagination
3. Epiboly
4. Convergence.

Answer: 3. Epiboly

Question 95. In the vertebrates, blastopore marks the region of the future :

1. Mouth
2. Nostril
3. Anus
4. Salivary glands.

Answer: 3. Anus

Plant Growth And Development MCQs NEET

Question 96. Amoeba reproduces by:

1. Binary fission
2. Budding
3. Fragmentation
4. Sporulation.

Answer: 1. Binary fission

Question 97. The period of development which is passed within the egg or the womb of the mother is called :

1. Post-natal
2. Embryonic
3. Natal
4. Extra-embryonic.

Answer: 2. Embryonic

Class 11 Biology MCQ  Question 98. When the offspring are developed by budding or fragmentation, the process is called :

1. Embryogenesis
2. Organogenesis
3. Gametogenesis
4. Blastogenesis.

Answer: 4. Blastogenesis.

Question 99. Malarial parasites multiply by the process of:

1. Budding
2. Fragmentation
3. Multiple fission
4. Binary fission.

Answer: 3. Multiple fission

Question 100. The constancy of the chromosomes is brought about by a special type of nuclear division is known as :

1. Mitosis
2. Meiosis
3. Amitosis
4. Parthenogenesis.

Answer: 2. Meiosis

NEET Biology Kingdom Monera Multiple Choice Questions

Question 1. An organism should be placed in the kingdom Moncra if it

1. Consists of a single cell
2. Has a cell wall
3. Is surrounded by a capsule
4. Lacks a nuclear membrane separating its genetic (material from the cytoplasm.

Answer: 4. Lacks a nuclear membrane separating its genetic (material from the cytoplasm.

Question 2. Newly started rice paddies produce poor crops until -they have established a flourishing population of cyanobacteria. This is probably because:

1. Die rice needs nitrogen fixed by the cyanobacteria
2. The rice cannot compete with weeds, which are poisoned by toxins produced by the cyanobacteria
3. The cyanobacteria use surplus nutrients from sewage in the rice paddies
4. The cyanobacteria lack proteins in their dna.

Answer: 1. Die rice needs nitrogen fixed by the cyanobacteria

Question 3. A wall-less moneran is:

1. Bacteria
2. Blue-green algae
3. Mycoplasma
4. Archaebacteria.

Answer: 3. Bacteria

Kingdom Monera MCQs For NEET

Question 4. Symbiotic nitrogen fixation is found in :

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

Answer: 1. Rhizobium

Question 5. Cyanobacteria do not possess :

1. Gene recombination
2. Flagella
3. Plasmid
4. Lamellasome.

Answer: 2. Flagella

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 6. Pili in bacteria represent :

1. Extrachromosomal genetic element
2. Cell membrane outgrowths of donor cells
3. Small flagella
4. Special bacterial cilia.

Answer: 2. Cell membrane outgrowths of donor cells

Question 7. Branched-chain lipids occur in the cell membranes of:

1. Archaebacteria
2. Mycoplasma
3. Actinomycetes
4. Streptomyces.

Answer: 1. Archaebacteria

Question 8. The decomposition of organic compounds in the presence of 02 without the development of an odoriferous substance is:

1. Nitrification
2. Decay
3. Denitrification
4. Nitrogen fixation.

Answer: 2. Decay

Question 9. The cell wall in all bacteria is composed of:

1. Lipid and protein
2. Murein
3. Proteins only
4. Cellulose and lipids.

Answer: 2. Murein

Kingdom Monera MCQs For NEET

Question 10. Genophore is the name of:

1. DNA of eukaryotes
2. DNA of protists
3. DNA of prokaryotes
4. Genes of drosophila.

Answer: 3. DNA of prokaryotes

Question 11. Micro-organisms in milk are killed by heat treatment at a controlled temperature without altering the natural characteristics of milk through a process called

1. Boiling
2. Immunization
3. Pasteurization
4. Sterilization.

Answer: 3. Pasteurization

Question 12. Naked dna is that which is :

1. Not covered by a nuclear envelope
2. Present in cytoplasm
3. Associated with histone proteins
4. Not associated with histone proteins.

Answer: 4. Not associated with histone proteins.

Question 13. In the bacterium Bacillus subtilis the cells often become attached from end to end forming long filamentous chains, which are embedded in a mass of mucilage forming a scum layer on the substratum. It is called as:

1. Palmella stage
2. Torula stage
3. Zoogloea stage
4. None of the above.

Answer: 3. Zoogloea stage

Question 14. Prokaryotic chromosome is :

1. A naked double-stranded
2. A single-stranded circular dna
3. Composed of DNA or RNA
4. Associated with non-histones.

Answer: 1. A naked double-stranded

Kingdom Monera MCQs For NEET

Question 15. Bacteria resemble yeasts because both have property

1. Degradation of food
2. Binary fission
3. Anaerobic respiration
4. Sexual reproduction.

Answer: 2. Binary fission

Question 16. One of the following does not apply to Escherichia coli:

1. Transformation
2. Transduction
3. Flagella
4. Diploid.

Answer: 4. Diploid.

Question 17. Which of the following are intermediate between viruses and bacteria?

1. Mycoplasma
2. Spirilla
3. Cyanobacteria
4. Variola.

Answer: 1. Mycoplasma

Question 18. Bacteria are found to be primitive organisms because they:

1. Are small, microscopic which are not seen with the naked eye
2. It causes serious diseases in human beings, domesticated animals, and crop plants.
3. Produce endospores which are very resistant to adverse conditions
4. Possess incipient nucleus and show amitotic division.

Answer: 4. Possess incipient nucleus and show amitotic division.

Question 19. Ih bacteria the most resistant stage is:

1. Capsuled vegetative cell
2. Newly divided cell
3. Endospore stage
4. Torula stage.

Answer: 3. Endospore stage

Question 20. Some diseases caused by bacteria are:

1. Measles, mumps, malaria
2. Tetanus, typhoid, tuberculosis
3. Smallpox, sleeping sickness
4. Poliomyelitis, psittacosis

Answer: 2. Tetanus, typhoid, tuberculosis

Bacteria MCQs For NEET

Question 21. bacterium which is commonly present in the intestine of man and animal is :

1. Vibrio comma
2. Escherichia.
3. Script
4. Pseudomonas citri.

Answer: 2. Escherichia.

Question 22. The chemotherapeutic substance derived from a living organism that has an inhibitory effect on parasitic organisms is known as:

1. Exotoxin
2. Antibody
3. Bactericide
4. Antibiotic.

Answer: 4. Antibiotic.

Question 23. Bacteria are plant-like because they have :

1. Rigid cell wall
2. Ability to reproduce
3. Both the above
4. None of the above.

Answer: 1. Rigid cell wall

Question 24. In transduction :

1. Bacteriophage transfers dna from donor to recipient cell
2. Extracellular dna enters the recipient cell
3. The donor cell survives
4. The donor and recipient cells survive.

Answer: 1. Bacteriophage transfers dna from donor to recipient cell

Question 25. Gram+ve bacteria have :

1. Thick and homogeneous cell walls
2. As much as 70% of peptide molecules
3. Either no lipids or less than 10% lipids
4. All the above.

Answer: 4. All the above.

Bacteria MCQs For NEET

Question 26. Honey, jams, jelly, and chutney are free of bacteria, because:

1. Bacterial cells are plasmolysed in these substrates
2. These substrates are poisonous
3. These substrates have a foul smell
4. These substrates have complex substances which cannot be utilized by bacteria for their nutrition.

Answer: 1. Bacterial cells are plasmolysed in these substrates

Question 27. Cyanobacteria is a :

1. Category of bacteria
2. Is the new name of all bacteria
3. New name of Myxophyceae or Cyanophyceae or blue-green algae
4. None of them.

Answer: 3. New name of Myxophyceae or cyanophyceae or blue-green algae

Question 28. Both bacteria and cyanobacteria are :

1. Prokaryotic
2. Eukaryotic
3. Eukaryotic as well as prokaryotic
4. None of the above.

Answer: 1. Prokaryotic

Question 29. If a bacterial cell is dividing every minute and takes one hour to fill a cup. It will require how much time to fill half of the cup.

1. 30 Minutes
2. 60 Minutes
3. 59 Minutes
4. 61 Minutes

Answer: 3. 59 Minutes

Question 30. The formation of vinegar from alcohol is caused by

1. Bacillus subtilis
2. Clostridium
3. Acetobacter aceti
4. Otobacter.

Answer: 4. Otobacter.

Bacteria MCQs For NEET

Question 31. The formation of vinegar from alcohol is caused by

1. Bacilius subtitles
2. Clostridium
3. Acetobacter aceti
4. Azotobacter.

Answer: 3. Acetobacter aceti

Question 32. Photosynthetic bacteria have:

1. Pigment system 1 (only one pigment system)
2. Pigment system 2
3. Both
4. Some other types.

Answer: 1. Pigment system 1 (only one pigment system)

Question 33. Which of the following causes nitrification?

1. Bacillus ramosus
2. Nitrosomonas
3. Nitrobacter
4. Both 2 and 3.

Answer: 4. Both 2 and 3.

Question 34. Bacteria having a tuft of flagella at both ends tire called :

1. Peritrichate
2. Bitrate
3. Amphitrichate
4. Lophotrichate.

Answer: 4. Lophotrichate.

Question 35. What turns the wine sour?

1. Light exposure
2. Aerobic bacteria
3. Anaerobic bacteria
4. High temperature.

Answer: 2. Aerobic bacteria

Question 36. Streptomycin is produced by :

1. Streptomyces grievous
2. Streptomyces soleus
3. Streptomyces fragile
4. Streptomyces venezuellae.

Answer: 1. Streptomyces grievous

Question 37. Botulism, a type of food poisoning, is caused by:

1. Rhizobium
2. Vibrio
3. Streptococcus
4. Clostridium botulinum.

Answer: 4. Clostridium botulinum.

NEET Previous Year Questions On Monera

Question 38. Fever typhoid is caused by the bacteria :

1. Xanthomonas typhous
2. Salmonella typhi
3. Bacillus diplococcus
4. Bacillus dysenteriae.

Answer: 2. Salmonella typhi

Question 39. Griffith performed experiments on which bacteria and concluded the occurrence of transformation in bacteria

1. Bacillus pneumonieae
2. Salmonella pneumonieae
3. Diplococcus pneumonieae
4. Xanthomonas pneumonieae.

Answer: 3. Diplococcus pneumonia

Question 40. Bacteria have flagella around the periphery of the cell. This condition is known as:

1. Peritrichate
2. Monotrichate
3. Lophotrichate
4. Amphitrichate.

Answer: 1. Peritrichate

Question 41. The estimated length of dna molecule in Escherichia coli is :

1. 1000 Pm
2. 100 Pm
3. 100 A
4. 1000 A.

Answer: 3. 100 A

Question 42. Form of sexual reproduction where genetic material is carried from one strain of bacteria to another by bacteriophage:

1. Transformation
2. Transduction
3. Mesomixis
4. Conjugation.

Answer: 2. Transduction

NEET Previous Year Questions On Monera

Question 43. The structure formed by the bacterial genome is called:

1. Nucleus
2. Nucleoid
3. Nucleoli
4. Nucleolus.

Answer: 2. Nucleoid

Question 44. Bacteria having a tuft of anger at our CML are called :

1. Monotridious
2. Amphitnehous
3. Cephalotrichoues
4. Peritrichous

Answer: 3. Cephalotrichoues

Question 45. Staplix kvivcus causes :

1. Food jvisoniug
2. Citrus canker
3. Denitrification
4. Vinegar fonnation.

Answer: 1. Food jvisoniug

Question 46. Photoautotrophic bacteria contain the pigment:

1. Chlorophyll
2. Bacteriochlorophyll
3. To carotene
4. No pigment.

Answer: 2. Bacteriochlorophyll

NEET Previous Year Questions On Monera

Question 47. E.coli lives in the human intestine and causes:

1. Urinary tract infection
2. Diarrhea
3. Meningitis
4. None of the above.

Answer: 4. None of the above.

Question 48. In e. Coli when the flagella rotates in a clockwise and anticlockwise direction, the movements are:

1. Jumping and hooping
2. Running and tumbling
3. Tumbling and hooping
4. Hooping and running.

Answer: 2. Running and tumbling

Question 49. A bacterial cell undergoes binary fission every twenty minutes. Starting with a single bacterium how many bacteria will be produced at the end of 3 hours?

1. 128
2. 256
3. 512
4. 1024.

Answer: 3. 512

Question 50. Which of the following is a free-living anaerobic nitrogen-fixing bacteria?

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

Answer: 4. Clostridium.

Question 51. E. Coli bacterium possesses a single large circular dna as its genetic material. This strand codes for :

1. 1000-2000 Different proteins
2. 2000-3000 Different proteins
3. 3000 To 4000 different proteins
4. More than 4000 different proteins.

Answer: 2. 2000-3000 Different proteins

Question 52. Bacteria that get their energy from fermentation and for whom oxygen is lethal are called:

1. Obligate anaerobes
2. Obligate aerobes
3. Facultative aerobes
4. Facultative anaerobes.

Answer: 1. Obligate anaerobes

Kingdom Classification MCQs For NEET

Question 53. The bacteria (treponema pallidum) that cause the v.d. Syphilis are :

1. Pseudomonas
2. Purple non-syphilis
3. Rickettsia
4. Spirochaetes.

Answer: 4. Rickettsia

Question 54. Which of the following jives in the gut of termites and helps them digest cellulose:

1. Plasmodium
2. Trypanosoma
3. Trichonympha
4. Trichosomes.

Answer: 3. Trichonympha

Question 55. An example of a chemoautotrophic bacterium is:

1. Lactobacillus
2. Nitrosomonas
3. E. Coli
4. Rhizobium.

Answer: 2. Nitrosomonas

Question 56. Bag included amongst :

1. Fungi
2. Prokaryotes
3. Bryophytes
4. Protista.

Answer: 2. Prokaryotes

Kingdom Classification MCQs For NEET

Question 57. Some bacteria produce resting spores during unfavorable conditions. They are:

1. Exports
2. Endosporcs
3. Aplanosporcs
4. Chlamydospores.

Answer: 2. Endosporcs

Question 58. The similarity between bacterium and cyanobacterium is:

1. Presence of flagella
2. Presence of 80 s ribosome
3. Presence of nucleoid
4. Presence of phycobilisomes.

Answer: 3. Presence of nucleoid

Question 59. Conjugation in bacteria was discovered by :

1. Jacob and Wollman
2. Zinder and Lederberg
3. Lederberg and Tatum
4. Beadle and Tatum.

Answer: 3. Zinder and lederberg

Question 60. Archaebacteria found in salty pans and salt marshes are

1. Methanogens
2. Thermoacidophiles
3. Ruminant symbiosis
4. Halophiles.

Answer: 4. Halophiles.

Kingdom Classification MCQs For NEET

Question 61. Prokaryotic cells have a volume range of :

1. 0.2 to 10 pm3
2. 100-1000 Pm3
3. 1000-10000 Pm3
4. 0.01 to 0.1 pm3.

Answer: 1. 0.2 to 10 pm3

Question 62. Prokaryotic flagella possess :

1. A helically arranged protein molecule
2. Protein membrane-enclosed fiber
3. Unit membrane-enclosed fiber
4. Microtubular (9+2) membrane.

Answer: 1. Protein membrane-enclosed fiber

Question 63. Organisms used in alcohol fermentation are:

1. Penicillium
2. Pseudomonas
3. Aspergillus
4. Saccharomyces.

Answer: 4. Saccharomyces.

Question 64. Tailed bacteriophages are :

1. Motile on the surface of bacteria
2. Non- motile
3. Actively motile in water
4. Motile on the surface of plant leaves.

Answer: 1. Motile on the surface of bacteria

Kingdom Classification MCQs For NEET

Question 65. A large number of organic food molecules can be prepared by:

1. Chemolithotrophs
2. Pseudomonas
3. Azotobacter
4. Mycoplasma.

Answer: 1. Chemolithotrophs

Most Important MCQs on Monera Question 66. Bacteria were first observed by :

1. W.h Stanley
2. Louis Pasteur
3. A.v. Leeuwenhoek
4. Robert koch.

Answer: 3. A.v. Leeuwenhoek

Question 67. “Little leaf” of brinjal is caused by :

1. Bacteria
2. Mycoplasma
3. Fungi
4. Venus

Answer: 2. Mycoplasma

Question 68. Crown gall is caused by

1. Mycobacterium
2. Bacteria
3. Clostridium
4. Erwinia

Answer: 2. Bacteria

Kingdom Monera MCQs For NEET

Question 69. Which of the following is an antibiotic?

1. Chloramphenicol
2. Ethwphous
3. Phosphon-d
4. Amo 11.1s

Answer: 1. Chloramphenicol

Question 70. Which of the following mg is a bacterial disease?

1. Measles
2. Tuberculosis
3. Rabies
4. Smallpox.

Answer: 2. Tuberculosis

Question 71. An aerobic nitrogen-fixing soil bacterium is :

1. Rhizobium
2. Clostridium
3. Azotobactcr
4. Rhodospirillum.

Answer: 3. Azotobactcr

Question 72. Hormogonia help in the reproduction of:

1. Cladophora
2. Bacteria
3. Archaebacteria
4. Cyanobacteria.

Answer: 4. Cyanobacteria.

Question 73. Which one of the following belongs to none?

1. Amoeba
2. Escherichia
3. Gelidium
4. Spirogyra.

Answer: 2. Escherichia

Question 74. Streptomyces ramosus is the source of the antibiotic :

1. Chloromycetin
2. Erythromycin
3. Aureomycin
4. Terramycin.

Answer: 4. Terramycin.

Kingdom Monera MCQs For NEET

Question 75. The cells of cyanobacteria and bacteria exhibit similarity in having:

1. Nuclei
2. Centrosome
3. Plastids
4. Dna.

Answer: 4. Dna.

Question 76. Bacteria without flagella are known as :

1. Monotrichous
2. Lophotrichous
3. Peritrichous
4. Atrichous.

Answer: 4. Atrichous.

Question 77. Chromoplasm is part of protoplast in :

1. Actinomycetes
2. Myxobacteria
3. Cyanobacteria
4. Eubacteria.

Answer: 3. Cyanobacteria

Question 78. Which of the following is not a bacterial action?

1. sewage disposal
2. Ripening of cheese
3. nitrogen fixation
4. Precipitation.

Answer: 4. Precipitation.

Question 79. The vinegar is prepared from sugary molasses by the activities of:

1. Fa; diplococcus
2. FB; acetobacter acetic
3. Staphylococcus
4. B. Subtilis.

Answer: 2. Fb; acetobacter acetic

Question 80. Genophore is made up of:

1. Rna arid histones
2. Histones and non-histones
3. A single-stranded dna
4. A double-stranded dna.

Answer: 4. A double-stranded dna.

Question 81. In rice fields, the soil fertility can be improved by :

1. Rhizobium
2. Sod. Chloride
3. Gypsum
4. Blue-green algae.

Answer: 4. Blue-green algae.

Kingdom Monera MCQs For NEET

Question 82. Which it billowing is with denitrification

1. Uhiobinm
2. Srudomnuns
3. Otohacler
4. Khodospirillum.

Answer: 2. Srudomnuns

Question 83. Which of the following cells is a prokaryote

1. Bacterium
2. Virus
3. Both 1 and 2
4. Green algae.

Answer: 1. Bacterium

Question 84. Peptidoglycan forms many layers in the wall of:

1. Gram-ve bacteria
2. Gram neutral bacteria
3. Gram -i-ve bacteria
4. All of them.

Answer: 3. Gram -i-ve bacteria

Question 85. Which era is dubbed the age of prokaryotic microbes?

1. Palaeozoic
2. Proterozoic
3. Precambrian
4. Archaeozoic.

Answer: 4. Archaeozoic.

Question 86. Sexual reproduction is absent in:

1. Ulothrix
2. Volvox
3. Spirogyra
4. Nostoc.

Answer: 4. Nostoc.

Bacteria MCQs For NEET

Question 87. Salmonellosis is the process of:

1. Food poisoning by bacteria
2. Reproduction by bacteria
3. Manifestation of typhoid
4. Decomposition by bacteria.

Answer: 1. Food poisoning by bacteria

Question 88. Meningitis a disease that is responsible for membrane damage of the brain is caused by :

1. Neisseria
2. A fungus
3. Bacillus
4. Bordetella.

Answer: 1. Neisseria

Question 89. Which of the following bacterium converts the sucrose into dextrin

1. Spirillum solutions
2. Leuconostoc mesenteroids
3. Bacillus megatherium
4. Both 1 and 2.

Answer: 2. Leuconostoc mesenteries

Question 90. When bacteria are rod-like and cubical packet of 8 cocci, are called as:

1. Bacilli and sarcina
2. Spirilla and cocci
3. Sarcina and vibrio
4. Spirilla and sarcina.

Answer: 1. Bacilli and sarcina

Question 91. Whose cell wall dissolves by antibiotic action :

1. Bacteria
2. L-form bacteria
3. Mycoplasma
4. Actinomycetes.

Answer: 2. L-form bacteria

Bacteria MCQs For NEET

Question 92. Special taste is developed in the tea leaves by fermentative action of:

1. Mycococcus candisans
2. Megatherium micrococcus
3. Bacillus megatherium
4. Clostridium acetobutylicum.

Answer: 1. Mycococcus candisans

Question 93. An episome in bacteria is:

1. Nutritional factor
2. Sex factor
3. Cofactor
4. None of these.

Answer: 2. Sex factor

Question 94. Aureomycin and chloramphenicol are obtained from :

1. Strcptomyces aureofaciens and s. Ramosus
2. S. Venezuelae and s.rimosus
3. S. Aureofaciens and s.fradiae
4. S. Aureofaciens and s. Venezuela.

Answer: 4. S. Aureofaciens and s. Venezuela.

Question 95. Chloramphenicol ami erythromycin (broad speetmm antibiotics Produced by:

1. Rhizobium cnieillmm
2. Strcptomyccs
3. Niirobnetct.

Answer: 3. Niirobnetct.

Question 96. Spiroplasms arc also walks nipple layered unit membrane-covered orgasms like mycoplasma but they differ from them in being :

1. Non-infections
2. Satisfying Koeh’s postulates
3. Motile and helical filamentous
4. None of the above.

Answer: 3. Motile and helical filamentous

Question 97. Term spiroplastna was suggested by:

1. Pavis and Worley
2. Worley
3. Davis
4. Ehrenberg.

Answer: 1. Pavis and Worley

Bacteria MCQs For NEET

Question 98. Rhizosphere bacteria are present around the;

1. Leaf surface
2. Floral surface
3. Root surface
4. Shoot surface.

Answer: 3. Shoot surface.

Question 99. A mixture of bacteria, viruses, and mycoplasma is drained through a filter with 450 pore size which of these would not pass through:

1. Virus
2. Mycoplasma
3. Bacteria
4. All of these.

Answer: 3. Bacteria

Question 100. A chain of spherical bacteria is called streptococci. When spherical cocci are found in grape-like irregular aggregates, they are called :

1. Sarcinae
2. Staphylococci
3. Palisade
4. Streptobacilli.

Answer: 2. Staphylococci

Question 101. A cubical packet of 8 cocci is called:

1. Staphylococcus
2. Vibrio
3. Gaffkva
4. Sarcina.

Answer: 4. Sarcina.

Bacteria MCQs For NEET

Question 102. Monerans are plants because they have :

1. Ability to synthesize vitamins
2. Rigid cell wall
3. Both  and
4. None of the above.

Answer:  3. Both  and

Question 103. “Bacillus thuringiensis is used to control:

1. Bacterial pathogens
2. Fungal pathogens
3. Nematodes
4. Insect pests.

Answer: 4. Insect pests.

Question 104. Penicillin kills bacteria by :

1. Suppression of cell wall synthesis
2. Lysis of protoplasm
3. Interfering with RNA synthesis
4. Inhibiting dna synthesis.

Answer: 1. Suppression of cell wall synthesis

Question 105. Which of the following antibiotics is more a research tool rather than used for clinical purposes :

1. Penicillin
2. Terramycin
3. Actinomycin-d
4. None of these.

Answer: 3. Actinomycin-d

Biological Classification MCQ For NEET Question 106. Doxycycline treatment cures :

1. Aids caused by virus
2. Polio caused by virus
3. Measles caused by virus
4. Male sterility caused by mycoplasma.

Answer: 4. Male sterility caused by mycoplasma.

Question 107. Wall is not pirseni in :

1. Mycoplasma
2. Aciiiiomycclcs
3. Vituses
4. L.-Loim baelcria.

Answer: 1. Mycoplasma

NEET Previous Year Questions On Monera

Question 108. Penicillin and vancomycin do not ail late mycoplasma because :

1. Prokaryotic and unicellular
2. Eukaryotic and unicellular
3. There is no nucleus
4. There is no cell wall.

Answer: 4. There is no cell wall.

Question 109. Llypersaline and hyperthermal aquatic environments are inhabited mostly by :

1. Eubacteria
2. Micro fungi
3. Cyanobacteria
4. Archacbactcria.

Answer: 4. Archacbactcria.

Question 110. Peritrichous bacteria have :

1. Flagella all over the body
2. Tuft of flagella at one end
3. Tuft of flagella at both ends
4. Single flagellum at one end.

Answer: 1. Flagella all over the body

Question 111. A bacterial cell contains :

1. Mesosomes, Golgi bodies, and nucleoid
2. Mesosomes and Golgi bodies
3. Mesosomes and nucleoid
4. Golgi bodies and nucleoids.

Answer: 3. Mesosomes and nucleoid

Question 112. To develop flavor and taste in tobacco, leaves are processed with bacterium:

1. Mycococcus candisans
2. Megatherium micrococcus
3. Aerobacter
4. None of the above.

Answer: 2. Megathenium micrococcus

Question 113. Magnesium ribonuclease is present in :

1. Gram (+) ve bacteria
2. Gram (-) ve bacteria
3. Both 1 and 2
4. None of the above.

Answer: 1. Gram (+) ve bacteria

Question 114. The bacterial decomposition of nitrogenous organic compounds in the absence of abundant oxygen usually results in the formation of substances of offensive odor, chiefly sulfur compounds. Such anaerobic decomposition is called :

1. Nitrification
2. Denitrification
3. Putrefaction
4. N2 fixation.

Answer: 3. Putrefaction

NEET Previous Year Questions On Monera

Question 115. Bacteria were called ‘tiny animalcules’ by Leeuwenhoek who discovered them from tartar scrapped from teeth. Who coined the term bacteria:

1. Ehrenberg
2. Nageli
3. Pasteur
4. Koch.

Answer: 1. Ehrenberg

Question 116. Name the bacterium that gets its energy from fermentation and if oxygen is given, it dies:

1. Obligate aerobe
2. Facultative anaerobe
3. Obligate anaerobe
4. Aerobe.

Answer: 3. Obligate anaerobe

Question 117. During gram’s staining :

1. Gram (+) ve bacteria take crystal violet stain
2. All bacteria take crystal violet stain
3. Only gram (-) ve bacteria take crystal violet stain
4. Gram (-) ve bacteria lose this stain after alcohol treatment.

Answer: 4. Gram (-) ve bacteria lose this stain after alcohol treatment.

Question 118. Compared to gram(-) bacteria. Gram (+) vc bacteria:

1. Are more resistant to antibiotics
2. Have more complex cell walls
3. Have less muicopcptidc
4. Retain crystal violet dye even after alcohol treatment.

Answer: 4. Have more complex cell walls

Question 119. Cyanobacteria living inside (the protozoans are called:

1. Cyanellc
2. Blue-green algae
3. Mvxophyceac
4. Euglenoids.

Answer: 1. Cyanellc

Question 120. The true diploid condition in bacteria is not obtained due to the reasons:

1. Only a part of a chromosome is transferred to the female cell
2. Introduced dna merely adds to the original dna of the female cell
3. Introduced dna replaces a part of the original dna of the female cell
4. All of the above.

Answer: 1. Only a part of a chromosome is transferred to the female cell

Most Important MCQs on Monera Question 121. Water bloom occurs mainly due to the presence of:

1. Cyanobacteria
2. Insects
3. Bacteria
4. Red algae.

Answer: 1. Cyanobacteria

Question 122. Which one of the following is a false statement regarding plasmids:

1. Plasmids are extrachromosomal materials found in bacterial cells
2. Most plasmids can be transmitted from cell to cell by infection without bringing about the death of host cells
3. Plasmids can be integrated into the host chromosomes
4. Plasmids are integrated but inert parts of the genetic element.

Answer: 2. Most plasmids can be transmitted from cell to cell by infection without bringing about the death of host cells

Question 123. Which of the following is a bacterial disease?

1. Club rot disease of cotton
2. Angular leaf spot disease of cotton
3. Leaf spot disease of turmeric
4. Wilt disease of tomato.

Answer: 2. Angular leaf spot disease of cotton

Question 124. Which of the following causes crown gall in plants :

1. Erwinia carotovora
2. Pseudomonas solanacearum
3. Agrobacterium tumefaciens
4. Xanthomonas malvacearum.

Answer: 3. Pseudomonas solanacearum

Question 125. Match the terms in column I with those in column d:

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

Answer: 4. 1-C,2-A,3-D,4-B

Question 126. Which of the following pairs is/arc correctly matched:

1. E.coli— circular dna
2. Tobacco mosaic virus—single-stranded RNA
3. Rcovirus—double-stranded RNA

Select the correct answer using the codes given below Codes:

1. A alone
2. A, b and c
3. A and c
4. B and c.

Answer: 2. A, b and c

Most Important MCQs on Monera Question 127. Match list 1 wish list 2 and select the correct answer using the codes given below the lists-

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

Answer: 2. 1-D,2-A,3-B,4-C

Question 128. Wine turns sour because of :

1. By fermentation of sugar by lactobacillus
2. By fermentation of sugar by Aspergillus
3. By fermentation of sugar by saccharomyces cerevisiae
4. Is a two-step process, first involving fermentation of sugar by yeast and second involving fermentation of ethyl alcohol by acetic acid bacteria.

Answer: 4. Is a two-step process, first involving fermentation of sugar by yeast and second involving fermentation of ethyl alcohol by acetic acid bacteria.

Question 129. Clear areas of agar plates containing phage particles as well as bacteria are called:

1. Bacteriophage
2. Transparencies
3. Plaques
4. Holes.

Answer: 3. Plaques

Question 130. Bacteria do not have a major role in the production of the following

1. Coffee
2. B-complex
3. Cheese
4. Bread.

Answer: 4. Bread.

Question 131. Episome or f factor is the extrachromosomal genetic material of bacteria, useful in:

1. Control of essential characters
2. Genetic recombination
3. Formation of endospores
4. Nitrogen fixation.

Answer: 2. Genetic recombination

Question 132. A scientist wants to try to grow a culture of an animal virus. Which of the following would most likely be a suitable cultural medium?

1. Boiled and cooled water with minerals and vitamins added.
2. Sterile jelly made with malt and agar.
3. An infertile egg.
4. Living chick embryos.

Answer: 4. A living chick embryo.

Biotechnology And Its Applications For NEET

Biotechnology can be defined as the use of microorganisms, plain and animal cells for commercial-scale production of biopharmaceuticals and for human welfare.

The Applications Of Biotechnology Include:

1. Therapeutics
2. Diagnostics
3. Genetically modified crops for agriculture
4. Processed food
5. Bioremediation
6. Energy production and
7. Waste treatment

The Three Critical Research Areas Of Biotechnology Are:

1. Providing the best catalyst in the form of an improved organism, usually in the form of a microbe or pure enzyme.
2. Creating optimal conditions through engineering for a catalyst to function.
3. Downstream processing technologies to purify the protein/organic compound for marketing.

Read and Learn More NEET Biology Notes

Applications Of Biotechnology In Agriculture For NEET

The Three Options For Increased Food Production Are:

• Agrochemical-based agriculture.
• Organic agriculture and
• Genetically engineered crop-based agriculture.

The Green Revolution succeeded in increasing the yield of crops mainly due to

• Use of improved varieties of crops and
• Use of agrochemicals (fertilizers and pesticides).
• Further increases in the yield with the existing varieties of crops are not possible using conventional methods of breeding.
• Agrochemicals cause soil and water pollution and are too expensive for farmers.

Biotechnology And Its Applications Neet Notes

Genetically Modified Crops:

A transgenic crop incorporates and expresses a transgene. A prevalent designation for transgenic crops is genetically modified crops, or GM crops.

The methodologies employed in the cultivation of transgenic crops provide two distinct advantages:

1. Any gene, whether derived from an organism or manufactured chemically, can be utilized for transfer
2. The alteration in genotype can be meticulously regulated since only the transgenic is incorporated into the crop genome.

Genetically Modified Crops Contrasting Breeding Activities:

• Only genes existing in specific species can undergo hybridization within those species.
• Alterations arise in all qualities for which the parental organisms utilized in hybridization exhibit differences.
• Upon the introduction of a transgene into an organism’s genome, it may accomplish one of the following outcomes:
• Generates a protein that is the subject of our interest.
• Generates a protein that independently manifests the desired trait.
• Alters an established metabolic pathway to provide a novel end product.
• Inhibits the expression of a pre-existing native gene.

Hirudin is a protein that inhibits coagulation. The gene that encodes hirudin was produced chemically. The gene was subsequently introduced into Brassica napus, resulting in the accumulation of hirudin in the seeds. Hirudin is refined and utilized as a pharmaceutical agent. The transgene product is the primary focus of interest.

The ‘Flavr Savr’ tomato variety exemplifies the suppression of a native tomato gene’s expression. The expression of a native gene can be inhibited by many techniques.

The enzyme polygalacturonase facilitates fruit softening by degrading pectin.

• The transgenic tomato cultivar ‘Flavr Savr’ exhibited a cessation of polygalacturonase production.
• Consequently, the fruits of this tomato variety maintain freshness and preserve their flavor significantly longer than those of other tomato types.
• Furthermore, the fruits exhibit an enhanced flavor and elevated total soluble solids, which serve as an unforeseen advantage.

The final two elements are under investigation through various tests prior to arriving at a definitive conclusion.

Genetically Modified Food:

The food prepared from the produce of genetically modified (= transgenic) crops is called genetically modified food, or in short, GM food. GM food differs from the food prepared from the produce of conventionally developed varieties mainly in the following aspects.

• Genetically modified food contains the protein produced by the transgene in question, for example, Cry protein in the case of insect resistance varieties.
• Genetically modified food contains the enzyme produced by the antibiotic resistance gene that was used during gene transfer by genetic engineering.
• Genetically modified food contains the antibiotic resistance gene itself.
• Genetically modified food t has been argued that the above features of GM foods could lead to the following problems when they are consumed. Firstly, the transgene product may cause toxicity and/or produce allergies. Secondly, the enzyme produced by the antibiotic resistance gene could cause allergies, since it is a foreign protein.
• Finally, the bacteria in the alimentary canal of humans could take up the antibiotic resistance gene in GM food. These bacteria would then become resistant to the concerned antibiotic. As a result, these bacteria could become difficult to manage.

The scientists involved in the production of transgenic crops are addressing to these concerns. Efforts are being made to use other genes in place of antibiotic resistance genes. The toxic and allergenic actions of the transgene product can be adequately examined by detailed assays using suitable animal models.

Biotechnology For NEET GM Products Benefits And Controversies

GM Products Benefits And Controversies Benefits

1. Crops
   1. Enhance taste and quality
   2. Reduced maturation time
   3. Increased nutrients, yields, and stress tolerance
   4. Improved resistance to disease, pests, and herbicides
   5. New products and growing techniques.
2. Animals
   1. Increased resistance, productivity, hardiness, and feed efficiency
   2. Better yields of meat, eggs, and milk
   3. Improved animal health and diagnostic methods.
3. Environment
   1. “Friendly” bioherbicides and bioinsecticides
   2. Conservation of soil, water, and energy
   3. Bioprocessing for forestry products
   4. Better natural waste management
   5. More efficient processing.
4. Society: Increased food security for growing populations.

GM Products Benefits And Controversies Controversies Safety:

1. Potential human health impact
2. Allergens, transfer of antibiotic resistance markers, unknown effects
3. Potential environmental impact
4. Unintended transfer of transgenes through cross-pollination, unknown effects on other organisms (for example, soil microbes), and
5. Loss of flora and fauna biodiversity

Biotechnology And Its Applications Neet Notes

Biotechnology For NEET Applications Of Genetically Engineered Microbes

Nif genes, Found in Rliizobiuin leguminosarum may be transferred to major food crops to increase food production without using expensive fertilizers

Introduction Of Gene For Coding: Vitamins, antibiotics, and hormones from higher animals to bacteria—thus Bacteria will act as living factories.

Production Of Pest Resistant Plants Bt Cotton.

The soil bacteria Bacillus thuringiensis synthesizes crystal proteins known as Cry proteins, which are lethal to the larvae of insects such as tobacco budworms, armyworms, beetles, and mosquitoes.

• The Cry proteins are present as inactive protoxins and are transformed into active toxins upon ingestion by the insect, as the alkaline pH of the stomach solubilizes the crystals.
• The active toxin adheres to the epithelial cell surface of the midgut and forms pores.
• This induces cellular swelling and lysis, resulting in the insect’s (larva’s) demise.
• The cry genes that encode this protein are extracted from the bacterium and integrated into several crop plants like as cotton, tomato, corn, rice, and soybean.
• The proteins expressed by the specified cry genes regulate the corresponding pest resistance.
• Cry 1 Ac and Cry 2 Ab regulate cotton bollworm populations.
• Cry 1 Ab regulates the borer.
• Cry 3 Ab targets the Colorado potato beetle, while Cry 3 Bb targets the corn rootworm.

Protection Against Nematodes

• A nematode Meloidogyne incognita infects tobacco plants and reduces their yield.
• The specific genes (in the form of cDNA) from the parasite are introduced into the plant using Agrobacterium as the vector.
• The genes are introduced in such a way that both sense/coding RNA and antisense RNA (complementary to the sense/coding RNA) are produced,
• Since these two RNAs are complementary, they form a double-stranded RNA (ds RNA).
• This neutralizes the specific RNA of the nematode, by a process called RNA- interference.

As a result, the parasite cannot live in the transgenic host and the transgenic plant is protected from the pest.

• Tomato resistant to Homeworm larvae.
• Similarly Tobacco, Populus, etc. with the help of Agrobacterium tumefaciens
• Transgenic potato and tobacco plants that produce human serum albumin (USA)
• Transgenic potato plants, with increased levels of cyclodextrins.
• Transgenic tobacco plants with increased levels of mannitol
• Transgenic plant for hybrid seed production.

Genetically Modified Food:

A tomato called Flavr Savr has been created to have a better flavourful shelf-life. It is due to delayed ripening.

This has been achieved in reducing the contents of cells with a degrading enzyme called as polygalacturonase which leads to tomato fruit ripening. Another example of transgenic modified food is transgenic rice with higher vitamin A contents.

Transgenic Animals:

We can produce new animals and human beings, having traits tailored according to our own will.

Biotechnological Applications For NEET In Medicine

Therapeutic Agents: Proteins with potential as pharmaceutical agents are produced by using genetically engineered organisms. Enzymes have also been used for this purpose, for example, DNase 1 and alginate lyase have been used in aerosols. Some known examples are given below:

1. Human growth hormone obtained from E. coil is used for the treatment of dwarfs.
2. Chorionic gi nadotropin hormone produced by genetic engineering is used for the treatment of infertility.
3. Interferons produced by E. coli are commercially used for the treatment of viral infections and cancer. Interferons were first obtained through DNA recombinant technique by Charles Weisman in 1980. He inserted the gene for interferon production in E. coli.
4. Interleukins produced by E. coli are used to stimulate the immunity system.
5. Tissue Plasminogen Activator (TPA) – an enzyme is used for dissolving blood clots after a heart attack and stroke.
6. Antihemophilic human factor 8 is used by people with hemophilia to prevent and control bleeding or to prepare them for surgery.
7. Platelet-derived growth factor produced by recombinant DNA technology is useful for stimulating wound healing.
8. Penicillin G acylase is also produced by genetic engineering. This enzyme is used for converting penicillin into 6- 6-amino penicillin acid for the formation of new antibiotics.

Biotechnology And Its Applications Neet Notes

Molecular Diagnosis: Recombinant DNA molecules and techniques like PCR (Polymerase Chain Reaction; are used for early diagnosis of disorders.

• Cloned genes when expressed to produce recombinant proteins, help in developing sensitive diagnostic techniques like ELISA.
• The cloned genes are also used as ’probes’ to detect the presence of complementary DNA strands.
• A probe is a piece of single-stranded DNA that is tagged with a radioactive molecule and it is used to find its complementary DNA by hybridisation.
• It is followed by the detection of radioactivity by autoradiography.
• The presence of a normal or mutant gene can be detected using such a method.
• PCR is used to detect HTV and to detect mutations in genes.

Biotechnology For NEET Genetically Engineered Insulin (Humulin)

Human insulin consists of so short polypeptide chains: chain A and chain B linked by disulfide bridges.

• Insulin is secreted as prohormone which has to be processed before it becomes a mature and functional hormone.
• The prohormone contains another polypeptide called C-peptide, which is removed during maturation.

Gene For Coding Insulin: From humans to bacteria is transferred and the insulin produced is called Humulin. In 1983. American Company Eli Lily produced genetically engineered Insulin called Humulin with the help of E. coli—Plasmid clone.

• In 1983, Eli Lilly, an American company, prepared two DNA sequences coding for chains A and B of human insulin and introduced them into the plasmids of Escherichia coli to produce insulin.
• The two chains produced were extracted and combined by creating disulfide bridges.

Biotechnology For NEET Gene For Preparing Interferon

Charles Weismann produced interferon through recombinants of E. coli. Production of transgenic plants for preparing recombinant products.

Many viral, bacterial, and protozoan vaccines are being synthesized through the technique of genetic engineering. These synthetically produced vaccines are the latest ones used in immunization. The gene coding for antigen protein is isolated from the pathogen and is cloned in bacterial host cells.

The social, economic, and environmental implications of genetic engineering techniques.

1. Generally prepared human insulin and edible vaccines will be readily available and also will be economical.
2. Transgenic crop plants for human consumption may cause concerns about safety due to unwanted properties they may have.
   • Hence the Indian Government has set up organizations that are authorized to make decisions regarding the validity of genetic modifications and the safety of introducing genetically modified organisms for public sendees.
   • One such organization is the Genetic Engineering Approval Committee (GEAC).
3. Some people believe that transgenic plants and animals can solve many human problems, especially of hunger and disease.

Biotechnology For NEET cDNA Library

The copy of DNA formed on mRNA is called cDNA. 1,000 – 30,000 types of various mRNA sequences can be obtained from a typical eukaryotic cell.

• cDNA library and cDNA clone bank are the populations of such viruses where each virus has at least one cDNA inserted plasmid is present.
• In a complete viral population, each member has from outside DNA sequence.
• It is easy to make a clone bank of those viruses that have DNA as genetic material, for example, the Influenza virus and Reovirus, etc.
• Prokaryotic gene has no introns, so cDNA is the continuous copy of mRNA while in Eukaryotes introns break the DNA molecules in small segments called exons.

Single Cell Proteins (SCP). Cells from different kinds of organisms such as bacteria, filamentous fungi, yeast, and algae are treated in different ways so that they are used as food or feed, and are called single cell protein.

The biomass is obtained from both mono and multicellular micro-organisms. The common substrate used for preparing such food containing SCP ranges from air, whey, sawdust, and paddy straw. SCA provides a valuable protein supplement in the human diet.

Biotechnology Mcq For Neet

Advantages Of Introducing Transgene

1. Formation of a desired protein.
2. Produces a protein that on its own produces the desired phenotype.
3. Modifies an existing biosynthetic pathway so that a new end product is obtained.
4. Prevents the expression of an existing native gene.

For example, Hirudin is a protein that prevents blood clotting. The gene encoding for hirudin was chemically synthesized’’ This gene was then transferred into Brassica napus. where hirudin accumulates in seeds. The hirudin is purified and used as medicine. In this case, the transgene product itself is the product of interest.

Biofertilizers: These are organisms that can bring about soil nutrient (like nitrogen or phosphorus) enrichment. The main sources of biolertilizers are bacteria, cyanobacteria, and fungi. Rhizobin from root nodules in legumes and cyanobacteria from symbiotic association with the form Azolla. The fungus and plant root association is termed mycorrhiza.

• They Are The Following Advantages Thus Preferred To Chemical Fertilizers:
  1. They are safe and moreover do not pollute the atmosphere.
  2. The surface runoff does not pollute water.
  3. They do not disturb the naturally occurring food chains.
  4. They are of low cost as compared to chemical fertilizers and pesticides.
  5. They do not cause any danger to the natural resources.
  6. Pesticides are poisons and non-specific in their target. They also kill useful predators and upset the natural balance.

Biopesticide involves the biological control of weeds, insects, and pathogens by some living organisms. It involves the use of insects feeding on a specific weed or the use of certain microorganisms viruses, bacteria, fungi, protozoa, or mites which will cause disease in weeds.

• The first bioherbicide was developed in 1961 and it was a mycoherbicide derived from the fungus Phytophthora palmivora which controls the growth of milkweed vines in citrus orchards.
• Another fine example of biological control of weeds is the control of overgrowth of cacti by the introduction of a cochineal insect (Cactoblastis cactorum) in India and Australia.

Applications Of Biotechnology Neet Questions

A few Examples Of Biopesticides Are: Biochemical active ingredients

1. Plant Volatile And Floral Attractants
   1. Lemon grass oil
   2. Eucalyptus oil
   3. Mustard oil (Allyl isothiocyanate)
   4. Geranium oil
   5. Citronella oil
2. Natural Insect Growth Regulators
   1. Dihydroazadirachtin
   2. Azadirachtin.
   3. Biological products Transgenic animals that produce useful biological products can be created by the introduction of the portion of DNA that codes for a particular product such as human proteins (α-antitrypsin) used to treat emphysema.
      • Similar attempts are being made for the treatment of phenylketonuria and cystic fibrosis. In 1997, the first transgenic cow, Rosie, produced human protein-enriched milk (2.4 g/L). The milk contained human alpha-lactalbumin and was nutritionally a more balanced product for human babies.
   4. Vaccine safety Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans. Transgenic mice are being used to test the safety of the polio vaccine.
   5. Chemical safety testing Transgenic animals are made that carry genes that make them more sensitive to toxic substances than non-transgenic animals. They are then exposed to the toxic substances and the effects studied. Toxicity testing in such animals will allow us to obtain results in less time.

Biopesticide Ethical Issues

• The manipulation of living organisms by the human race cannot go on any further, without regulation.
• Some ethical standards are required to evaluate the morality of all human activities that might help or harm living organisms.
• Going beyond the morality of such issues, the biological significance of such things is also important. Genetic modification of organisms can have unpredictable results when such organisms are introduced into the ecosystem.
• Therefore, the Indian Government has set up organizations such as GEAC (Genetic Engineering Approval Committee), which will make decisions regarding the validity of GM research and the safety of introducing GM organisms for public services.

The major bioethical concerns connected with exploits of biotechnology are

1. The use of animals in biotechnology causes great suffering to them.
2. When animals are used for the production of pharmaceutical proteins, they are virtually reduced to the status of a factory.
3. The introduction of a transgene from one species into another species violates the integrity of the species.
4. The transfer of human genes into animals (and vice-versa) dilutes the concept of humanness.
5. Biotechnology is disrespectful to living beings and only exploits them for the benefit of human beings.
6. Biotechnology may pose unforeseen risks to the environment, including risks to biodiversity.

Biological Resources Or Bioresources:

Biological Resources Or Bioresources include all those organisms that can be used to derive commercial benefits. Traditional knowledge related to bioresources is the knowledge developed by various communities over long periods of history, regarding the utilization of bioresources, for example, the use of herbs, etc. as drugs.

Often, this traditional knowledge can be exploited to develop modern commercial processes. The traditional knowledge suggests the direction to be followed and saves considerable time, effort, and expenditure for their commercialization. Institutions and companies of industrialized nations are collecting and exploiting the bioresources, as follows.

1. They are collecting and patenting the genetic resources themselves. For example, a patent granted in the U.S.A. covers the entire ‘basmati’ rice germplasm indigenous to our country.
2. The bioresources are being analyzed for the identification of valuable biomolecules. A biomolecule is a compound produced by a living organism. The biomolecules are then patented and used for commercial activities.
3. Useful genes are isolated from the bioresources and patented. These genes are then used to generate commercial products.
4. The traditional knowledge related to bioresources is utilized to achieve the above objectives. In some cases, the traditional knowledge itself may be the subject of a patent.

A west African plant, Pentadiplcmdra brazzeana produces a protein called brazzein, which is approximately 2,000 times as sweet as sugar. In addition, brazzein is a low-calorie sweetener. Local people have known and used the super-sweet berries of this plant for centuries.

• However, the protein brazzein was patented in the U.S.A. Subsequently, the gene encoding brazzein was also isolated, sequenced, and patented in the U.S.A. It is proposed to transfer the brazzein gene into maize and express it in maize kernels.
• These kernels with then be used for the extraction of brazzein. This development could have serious implications for countries exporting large quantities of sugar.

Biopatent:

A patent is a right granted by a Government to an inventor to prevent others from making commercial use of such an invention. At present patents are granted for biological entities and the various products obtained from these organisms, termed as biopatent. Biopatents are being granted for the following

1. Strains of micro-organisms
2. Cell lines
3. Genetically modified strains of living organisms
4. DNA sequences
5. The proteins prepared by DNA sequences
6. Biotechnological process
7. Production process
8. Products
9. Product application.

Biopiracy:

Exploitation of patent biological resources without proper permission is called biopiracy. The collection of such material without a benefit-sharing agreement is likely to find its way into the list of criminal violations in many countries.

• For thousands of years, neem has been used in India for killing pests and as medicine. One of the American companies patented neem. As a result, anybody using neem will have to pay for it. This was called as legalized theft. Biopiracy permits the piracy of gene resources and knowledge from non-western countries. Such piracy was claimed by them as an invention.
• Many biotechnology patents are very broad in their coverage. For example, one patent covers ‘all transgenic plants of Brassica family’. Such broad patents are considered morally unacceptable and fundamentally inequitable since these would enable financially powerful corporations to acquire monopoly control over biotechnological processes.
• They may, in the end, even come to control the direction of agricultural research, including plant breeding. Such a position would pose a threat to the global food security.
• Any organizations and multinational companies exploit and/or patent biological resources or bioresources of other nations without proper authorization from the countries concerned; this is known as biopiracy.
• The industrialized nations are rich in technology and financial resources but poor in biodiversity and traditional knowledge related to the utilization of bioresources. In contrast, developing nations ar poor in technology and financial resources, but are rich in biodiversity and traditional knowledge related to bioresources

Biowar:

The use of bioweapons originated in the 5th century. It is the use of biological weapons against humans and their crops and animals. A bioweapon is a device that carries and delivers pathological biological agents or toxins to a target. Recently Anthrax bacterium was sent by post after the attack. It causes anthracis.

Applications Of Biotechnology Neet Questions

Misconceptions About Biological Weapons

1. Technically difficult.
2. Will not be used because use is morally repugnant.
3. Rarely used, no chance of use of biological weapons in the near future.

Misconceptions About Biological Weapons Realities

1. Biological agents for biological warfare are not costly and can be produced with ease.
2. Detection or interdiction is almost impossible.
3. Use is likely to increase.
4. More dangerous than conventional weapons.

Misconceptions About Biological Weapons Real Threat

1. It is considered that by 1995, more than 18 countries had biological weapons.
2. Salmonella was used to contaminate salad bars in Oregan restaurants by members of a cult in 1984.
3. Two members of a Minnesota militia group were convicted for having ricin in 1995.
4. A lab. technician in Ohio placed orders for 3vials of Y. pestis by mail in 1995.

Potential Biological Weapon Agents. Biological Weapon agents can cause the following diseases

1. Anthrax
2. Smallpox (variala)
3. Botulism toxins
4. Plague
5. Q. (fever, chills, fatigue, etc.)
6. Tularemia (it can occur in humans in two forms; ulceroglandular and typhoidal).
7. Viral Encephalitis,
8. Viral hemorrhagic fevers.

Characteristics Of Biological Weapons That Make Them Attractive To Countries And Terrorists,

1. Cost efficiency. Biological weapons are low-cost weapons.
2. A large number of casualties. They cause far more casualties than chemical or conventional weapons.
3. Biological weapon agents are invisible, odorless, and tasteless once released.

Defence Against Biological Weapons

1. Respirator or gas mask;
2. Safer shelter;
3. Decontamination;
4. Vaccination
5. Antibiotics;
6. Detection mechanism.

Bioethics:

Bioethics are a framework of principles utilized to govern our actions concerning biological endeavors.

Biotechnological Applications In Medicine Neet

The principal bioethical issues are as follows:

1. The incorporation of transgenes from one species into another undermines species integrity.
2. The transfer of human genes to other animals and vice versa is unethical.
3. Creation of a clone.
4. May pose a threat to biodiversity.
5. The suffering of animals utilized in biotechnology will escalate.

Fermentation:

The anaerobic oxidation of food in the presence of micro-organisms which results in the production of alcohol and waste gas CO₂.

Immobilization Of Enzymes:

It is the process of fixing an enzyme or enclosing it in solid support so as to protect it from deactivation and attack of proteases, maintain enzyme purity, ability to recover it after reaction and perform the continuous reaction.

The methods which include covalently attaching the enzyme to a solid support, trapping it in a gel, crosslinking the enzyme molecules to one another, and encapsulating them in small artificial cells is called immobilization of enzymes.

NEET Biology Biotechnology And Its Applications Multiple Choice Questions

Question 1. How many recombinant therapeutics have been approved for human use the world over?

1. 12
2. 30
3. 20
4. 18

Answer: 2. 30

Question 2. Which of the following techniques serve the purpose of early diagnosis?

1. Recombinant DNA technology
2. PCR
3. ELISA

1. 1 only
2. 1 and 3 only
3. 1 and 2 only
4. 2 and 3.

Answer: 4. 2 and 3

Question 3. Which of the following techniques is based upon the principle of antigen-antibody interaction?

1. PCR
2. ELISA
3. Recombinant DNA technology
4. RNA interference.

Answer: 2. ELISA

Read and Learn More NEET Biology Multiple Choice Question and Answers

Question 4. Which of the following transgenic protein products has been used to treat emphysema?

1. α-1-antitrypsin
2. a-Lactalbuniin
3. Cry protein
4. C-peptide.

Answer: 1. α-1-antitrypsin

Biotechnology and its Applications Zoology NEET Question 5. The Bt toxin gene has been cloned from the bacteria and expressed in plants to provide resistance to insects without the need for insecticides. Select these resistant plants from the given list.

1. Cotton
2. Corn
3. Rice
4. Tomato
5. Potato
6. Soyabean

1. 1, 2, 3 and 4
2. 2, 3, 4 and 5
3. 1, 2, 5 and 6
4. All of these

Answer: 4. All of these

Biotechnology And Its Applications Mcq For Neet

Question 6. Which of the following is/are correct about the process of RNA interference?

1. This is used to prevent the infestation of protozoans.
2. It takes place in some eukaryotic and all prokaryotic organisms as a method of cellular defense.
3. The method involves silencing a specific mRNA due to a complementary dsRNA molecule.
4. It is a novel strategy to produce pest-resistant plants

1. 3 and 4
2. 2, 3 and 4
3. 1 and 3
4. 3 only

Answer: 1. 3 and 4

Question 7. Which ingredient was present in high concentrations in genetically modified (GM) rice as compared to the usual rice?

1. Protein
2. Carbohydrates
3. Na⁺ ions
4. Vitamin A.

Answer: 4. Vitamin A.

Question 8. Animals that have had their DNA manipulated to possess and express an extra gene are known as:

1. Foreign animals
2. Superior animals
3. Transgenic animals
4. Intergenic animals.

Answer: 3. Transgenic animals

Neet Biotechnology Mcqs With Answers

Biotechnology and its Applications Zoology NEET Question 9. About 95 percent of all existing transgenic animals are

1. Rabbits
2. Pigs
3. Crovs
4. Mice

Answer: 4. Mice

Question 10. Today, transgenic models exist for many human diseases which include:

1. Cancer
2. Cystic fibrosis
3. Rheumatoid arthritis
4. Alzheimer’s disease.

1. 1 and 3 only
2. 2 and 3 only
3. 1, 2 and 3 only
4. 1, 2, 3 and 4.

Answer: 4. 1, 2, 3 and 4.

Question 11. Which of the following is not a true statement with respect to Bt cotton?

1. Bt toxin is produced by a bacterium Hticillus tliuringH’nsix
2. It is an example of bio-pesticide
3. Bt toxin gene has been cloned in plants to provide resistance to insects
4. Bt cotton could decrease the amount of pesticide used.

Answer: 3. Bt toxin gene has been cloned in plants to provide resistance to insects

Biotechnology Previous Year Questions Neet

Question 12. Match the following genes in Column-A with the insect that can be protected from with their coded protein in Column-B.

1. 1(A), 2(C), 3(B)
2. 1(B), 2(A), 3(C)
3. 1(A), 2(B), 3(C)
4. 1(B), 2(C), 3(A).

Answer: 1. 1(A), 2(C), 3(B)

Question 13. Which protein would you like to be produced by genetic engineering as a cure for diseases like emphysema?

1. α-1-antitrypsin
2. Trypsin
3. Chymotrypsin
4. All of the above are required.

Answer: 1. α-1-antitrypsin

Question 14. ‘Rosie’ a transgenic cow is known to produce a type of milk that has all the following characteristics except:

1. Proteimeontent of 2.4 gm/litre
2. Has human α-lactalbumin
3. More balanced diet than normal cow milk for babies
4. Was produced for the first time in the year 2001.

Answer: 4. Was produced for the first time in the year 2001.

Question 15. According to the latest estimates, how many documented varieties of Basmati rice are grown in India?

1. 30
2. 27
3. 118
4. 125.

Answer: 2. 27

Question 16. An anti-bacterial compound that prevents mastitis in cows is:

1. α-1-antitrypsin
2. Lysostaphin
3. Lysozyme
4. Alginate lyase.

Answer: 2. Lysostaphin

 Question 17. Choose the incorrect statement with respect to Bioweapons

1. They are low-cost weapons
2. They cause more casualties than conventional weapons
3. They are extremely difficult to detect
4. Bacterium E. coli created a later scare in 2001.

Answer: 4. Bacterium E. coli was created later in 2001

Question 18. A set of standards by which a community regulates its behavior and activities in relation to the biological world is termed as:

1. Biopatent
2. Biopiracy
3. Patent
4. Biocthic.

Answer: 4. Biocthic.

Applications Of Biotechnology Neet Mcqs

Question 19. Nexia biotechnologies spliced spider genes into the cells of lactating:

1. Cow
2. Sheep
3. Goat
4. None of these.

Answer: 3. Goat

Question 20. How many varieties of rice have been estimated to be present in India’?

1. 2.000
2. 20,000
3. 200,000
4. 2,000,000.

Answer: 3. 200,000

Question 21. The use of bioresources by multinational companies and other organizations without proper authorization from the countries and people concerned without compensatory’ payment is called:

1. Bioethics
2. Biopiracy
3. Bioterror
4. Bioweapon.

Answer: 2. Biopiracy

Question 22. Amongst the following which characteristics is not applicable to Bt cotton?

1. Bt is the abbreviated term for botulinum toxin
2. Such cotton is resistant to armyworms and beetles
3. The toxin is activated in the body of the insect
4. The toxin is coded by a gene called ‘cry’.

Answer: 1. Bt is the abbreviated term for botulinum toxin

Question 23. Which biotechnology company is credited with the synthesis of genetically engineered human insulin for the first time?

1. Celera genomics
2. Cipla
3. Eli Lily
4. Ranbaxy.

Answer: 3. Eli Lily

Biotech Applications In Medicine Mcqs Neet

Question 24. Pick the odd one out

1. DNA micro-injection
2. RNA interference
3. Retrovirus-mediated gene transfer
4. Embryonic stem cell-mediated gene transfer.

Answer: 2. RNA interference

Question 25. In Xenotransplantation, a protein that causes graft rejection comes usually from transgenic

1. Cow
2. Mice
3. Pig
4. Sheep.

Answer: 3. Pig

Question 26. Transgenics have provided many pharmaceuticals in their milk, for the treatment of diseases. Which of the following has not been a successful story?

1. Phenylketonuria
2. SCID
3. Emphysema (hereditary)
4. CFTR.

Answer: 2. SCID

Question 27. Which is not true with respect to transgenic animals and their contribution to human welfare?

1. Transgenic mice are being tested to ensure the safety of the polio vaccine
2. Rosie’s milk contained the human gene insulin
3. Transgenic cows produce milk with less lactose
4. Transgenic sheep grow more wool.

Answer: 2. Rosie’s milk contained the human gene insulin

Question 28. The functional ADA cDNA can be introduced into the cells of the patient receiving gene therapy by using a vector constituted by

1. E. coli
2. Reovirus
3. Retrovirus
4. Agrobacterium.

Answer: 3. Retrovirus

Question 29. Which variety office was patented by a U.S. company even though the highest number of varieties of this rice is found in India?

1. Sharbati Sonora
2. Co-667
3. Basmati
4. Lerma Roja.

Answer: 3. Basmati

Question 30. Which step of Government of India has taken to cater to the requirement of patent terms and other emergency provisions in this regard?

1. Biopiracy act
2. Indian patents bill
3. RTI act
4. Negotiable Instruments Act.

Answer: 2. Indian patents bill

Biotechnology And Its Applications Mcq For Neet

Question 31. What is another term used for GMO (Genetically Modified Organisms)?

1. Cybrid organisms
2. Geromorphic organisms
3. Transgenic organisms
4. Conjoint twins.

Answer: 3. Transgenic organisms

Question 32. Which one of the following can be used as a permanent cure for ADA deficiency?

1. Bone marrow transplantation upon detection of disorder in adult
2. Enzyme replacement therapy at any point in life
3. Both 1 and 2
4. Gene therapy at early embryonic stages.

Answer: 4. Gene therapy at early embryonic stages.

Question 33. Which of the following is a transgenic product useful for the treatment of Haemophilia?

1. Factor 8
2. Antithrombin 2
3. α-1 -antitrypsin
4. Lysostaphin.

Answer: 1. Factor 8

Question 34. Who is responsible for obtaining interferons through recombinant DNA technique?

1. A.R. Bunting
2. Eli Lily
3. A. Tiselius.
4. Charles Weissmann

Answer: 3. A. Tiselius

Question 35. Select the incorrect statement

1. RNAi silencing takes place in all eukaryotic organisms as a method of cellular defense
2. RNAi requires silencing of mRNA by binding of complementary ssDNA molecule
3. Complementary nucleic acid could be from mobile genetic elements (transposons)
4. Ti plasmid with nematode-specific genes have been used in RNAi.

Answer: 2. RNAi requires silencing of mRNA by binding of complementary ssDNA molecule

Biotechnology and It’s Applications Biology NEET Question 36. Identify the correct match for the given columns.

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

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

Question 37. Rules of conduct that may be used to regulate our activities in relation to the biological world is called

1. Bioethics
2. Biowar
3. Biopatent
4. Biopiracy.

Answer: 1. Bioethics

Question 38. Transgenic mice are being used to test the safety of:

1. Polio vaccine
2. BCG vaccine
3. Antitrypsin
4. Hepatitis B vaccine.

Answer: 1. Polio vaccine

Question 39. Which genes encode the protein to control bollworm infection in cotton plants?

1. Cry 2 Ab
2. Cry 1 Ac
3. Both (1) and (3)
4. Amp^r.

Answer: 3. Both (1) and (3)

Neet Biotechnology Mcqs With Answers

Question 40. Which is Incorrect with respect to GM foods?

1. It contains the protein produced by the transgene in question
2. GM food contains antibiotic resistance gene itself
3. The enzyme produced by antibiotic resistance gene will not cause allergies
4. The bacteria is the gut of humans could be taken by antibiotic resistance genes.

Answer: 3. The enzyme produced by antibiotic resistance gene will not cause allergies

Question 41. Golden rice – a transgenic variety of rice is principally richer than normal rice in:

1. Cry 1 Ab
2. Hirudin
3. TPA
4. β-carotene.

Answer: 4. β-carotene.

Question 42. Southern blotting can’t be performed without

1. Restriction endonucleases
2. Agarose
3. Monoclonal antibodies
4. Both (1) and (2).

Answer: 4. Both (1) and (2).

Question 43. Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because:

1. Bacteria are resistant to the toxin
2. Toxin exists as a toxoid
3. Toxins exist as protoxins
4. Bacteria enclose toxins in a special sac.

Answer: 3. Toxins exist as protoxins

Question 44. What is the permanent curve of adenosine deaminase (ADA) deficiency in children?

1. Bone marrow transplantation.
2. Enzyme replacement therapy in which functional ADA is given to the patient by injection.
3. Infusion of genetically engineered lymphocytes (in which functional ADA-cDNA is introduced) into the patient’s body.
4. Introduction of gene isolated from bone marrow cells producing ADA, into cells at early embryonic stages.

Answer: 4. Introduction of gene isolated from bone marrow cells producing ADA, into cells at early embryonic stages.

Neet Biotechnology Mcqs With Answers

Question 45. Which gene controls the transcription of chain A and chain B required for humulin synthesis in E. coli?

1. β-lactamase
2. β-galactosidase
3. Poly galacturonic
4. Chitinase.

Answer: 3. Poly galacturonic

Question 46. Transgenic Brassica napus has been used for the synthesis of

1. Hirudin
2. Heparin
3. Polygalacturonase
4. Cry protein.

Answer: 1. Hirudin

Question 47. Which of these participates in the manufacturing of dextrans:

1. Mucor
2. Lactobacillus
3. Leuconostoc
4. Pseudomonas.

Answer: 3. Leuconostoc

Question 48. Which of the following is used for the manufacture of cosmetics?

1. Serotonin
2. Cholesterol
3. Shikonin
4. Keratin.

Answer: 3. Shikonin

Question 49. The technique by which virus detection can be made both in plants and animals is known as:

1. Enzyme-linked immunoabsorbent assay (ELISA)
2. Electrophoresis
3. Electron microscopy
4. Immunofluorescence

Answer: 1. Enzyme-linked immunoabsorbent assay (ELISA)

Question 50. Streptokinase (TPA) helps in:

1. Clearing blood clots
2. Increasing plasma
3. Dissolving tissues
4. Increasing O.P. of the cell.

Answer: 1. Clearing blood clots

Question 51. The enzyme diastase was identified by:

1. Payen and Persoz
2. Waksman
3. Christian Hansen
4. Alexander Fleming.

Answer: 1. Payen and Persoz

Question 52. The immobilization of the enzyme is achieved by:

1. Killing the cells without affecting enzymes
2. Attaching the enzymes covalently to a solid support
3. Entrapping the living cells in a gel
4. All of these.

Answer: 4. All of these.

Question 53. Interferons are:

1. Proteins released in minute quantities by animals or plant cells, on being infected with a virus
2. Proteins synthesized in large quantities by cells actively engaged in synthesis
3. Hormones released by cells in small quantities which influence some of the various physiological activities
4. Defensive mechanism.

Answer: 1. Proteins released in minute quantities by animals or plant cells, on being infected with the virus

Question 54. Magic bullets are:

1. Interferons
2. Vaccines
3. Monoclonal
4. Antigen-antibody cells, antibodies

Answer: 3. Monoclonal

Question 55. Cheese contains:

1. Proteins 20-35%, fats 20-3%
2. Fats 20-35%, protein 20-30%
3. Proteins double than fats
4. Fats double proteins.

Answer: 1. Proteins 20-35%, fats 20-3%

Question 56. The hybridoma technique was developed by:

1. Louis Pasteur
2. Edward Jenner
3. Georges Kohler
4. Burnet. and Caser Milstein

Answer: 3. Georges Kohler

Question 57. Some of the steps involved in the production of humulin are given below. Choose the correct sequence.

1. Synthesis of the gene (DNA) for human insulin artificially.
2. Culturing recombinant E. coli in bioreactors.
3. Purification of humulin.
4. Insertion of human insulin gene into a plasmid.
5. Introduction of recombinant plasmid into E. coli.
6. Extraction of recombinant gene product from E. coli.

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

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

NEET Biology Muscular System

• Movement is the displacement of body parts in relation to the body axis. It is a characteristic feature of living beings. Movements of, external and internal body parts occur.
• Locomotion is the displacement of the body from one place to another place. Locomotion is the basic character of animals. Locomotion enables the animals to protect their bodies to search and procure food and water, to find their mate, escape from predators, shift to a favourable environment and find a suitable breeding ground.
• Locomotion in acellular organisms takes place by three methods :
  1. Pseudopodial
  2. Ciliary
  3. Flagellar.
• Pseudopodial locomotion takes place in Amoeba.
• Ciliary locomotion takes place in Paramecium.
• Flagellar locomotion takes place in Euglena.
• Adult sponges are sedentary ties. fixed. Locomotion does not take place in them.
• Their larvae move by cilia.
• Locomotion in Hydra is muscular and also takes place by tentacles,
• Bending and swaying
• Looping
• Somersaulting

Read and Learn More NEET Biology Notes

• Gliding
• Walking
• Climbing
• Surfacing
• Floating
• Swimming.
• Locomotion in annelids takes place either by setae or parapodia. Locomotion by setae takes place in Pheretima and by parapodia in Nereis.
• Locomotion in leeches takes place by muscular contraction and suckers.
• Locomotion in arthropods takes place by jointed legs and wings.
• Locomotion in molluscs takes place by foot
• Locomotion in echinoderms takes place by tube feet
• Locomotion in vertebrates takes place by fins and limbs.

NEET Biology Muscular System Notes

NEET Biology Kingdom Protista Movements of External Body Parts

1. Collection of information by the movement of pinnae, ocular orbits, neck, etc.
2. Facial expressions and gestures
3. Preservation of balance
4. Movement of extremities and limbs for locomotion.
5. Acquisition of sustenance, Consumption of nourishment.
6. Nourishing offspring, Offensive and Defensive
7. Respiration.

NEET Biology Kingdom Protista Movements of Internal Body Parts

1. The heartbeat facilitates blood circulation.
2. Contraction and relaxation of the diaphragm, ribs, and lungs facilitate gaseous exchange.
3. Peristalsis is the pendular or segmental motion facilitating the transit of food through the alimentary canal.
4. Peristalsis facilitates the movement of urine through the urinary system, while also generating sound.
5. Movements of the genital tract and uterine wall during oviposition and parturition.
6. Muscular activity in the movements of different body components.

NEET Biology Kingdom Protista Non Muscular Movements

1. Such movements occur in protists and individual cells in higher organisms in the following ways:
2. Pseudopodial/Amoeboid Movements. The movements occur using temporary protoplasmic outgrowths called pseudopodia.

• Pseudopodia can develop in any direction due to the flow of protoplasm. Fresh pseudopodia develop as older ones are withdrawn.
• Amoeba and iLs relatives creep using pseudopodia. The movements occur in macrophages and leucocytes. Because of them the cells can reach all body parts and engulf pathogens.

1. Cyclosis/Cytoplasmic or Protoplasmic Streaming. It occurs only inside eukaryotic cells. Cyclosis helps in the circulation of materials in the cells.
2. Flagellar Movements. Flagella perform locomotion In euglenoids and other flagellate pivots, Chlamydomonas and other unicellular/colonial motile green algae sperm, etc. Flagellate choanocytes bring about the circulation of water in the canal system of sponges.
3. Ciliary Movements. Paramecium and other ciliates swim using cilia.
4. Undulation movements due to plasma membrane as in fibroblasts.

Muscular System NEET Study Material

NEET Biology Kingdom Protista Types Of Muscles

1. Three types of muscles have been categorized based on the structure of their fibres.
2. Details discussed in a chapter on (Animal tissues)

• Skeletal muscles (Striated muscles). These generate external movement associated with the skeleton, remain attached to bone through the tendon, under conscious control and hence also termed as voluntary muscle. In lower magnification, these have transverse stripes hence also called striped or striated muscles.
• Smooth Muscles (Visceral muscles)
• Unstriped; hence structurally different from striated and cardiac muscles.
• Muscle cell spindle-shaped (not cylindrical) uninucleated each formed of single myoblast.
• Actin filaments remain attached, to dense bodies in the cytoplasm.
• There is no myofibril, no sarcomere and no Z-line.
• Actin and Myosin filaments are not arranged in any pattern hence no striations.
• Involuntary muscle, under ANS control, is found in visceral organs (visceral muscle).
• Cardiac muscle. This is also striated muscle but under involuntary control, hence has a rhythmic pattern of contraction with varying frequency.
• This is an untiring muscle (no fatigue) and keeps on acting lifelong.
• Being striated it is structurally similar to skeletal muscle except for the presence of (0 Cross fibres, besides parallel fibres

1. Intercalated discs – which represent the joints of two myoblasts.
2. The contraction pattern is rhythmic and the rate of contraction is controlled by the autonomic nervous system (ANS).
3. They do not get fatigued, and work ceaselessly throughout their lives.
4. Generates impulse-like nerve (i.e. the myogenic heart of vertebrates).

NEET Biology Kingdom Protista Chemical Composition Of Muscle Fibres

• Water 75%
• Proteins 20% (Myosin, actin, tropomyosin troponin complex and enzymes)
• Proteins of Muscles
• Actin, the filament'(F-actin) is formed by polymerization of G-actin monomer. It has the site, occupied by regulatory protein troponin and tropomyosin, for the attachment of myosin.
• Tropomyosin is a rod-shaped fibrous protein helically wrapped around the actin filament along its groove.
• Troponin is a small globulin protein with l components: troponin-e, troponin-l and troponin-T masking the site on F-mMin lor attachment of myosin.

1. Myosin is a versatile protein with both fibrous and globular parts. The fibrous part aggregates to find the filament while the globular part, projects out at both ends as cross bridges or heads. 1 lead is formed of HMM (heavy mcromysoin) consisting of Sub-fragment-1 and the neck (or hinge). The tail part is formed of LMM (light meromyosin). The head acts as ATPnse which after connecting with actin hydrolyse ATP.
2. Mineral and organic compounds 5% (K⁺ is the chief mineral constituent, Mg⁺⁺, P⁺⁺, Na⁺ and Ca⁺ 4  are present in minute quantities.
3. Organic compounds are present in the form of glycogen, lipids, steroids and non-poric nitrogenous compounds.

NEET Biology Kingdom Protista Some Major Muscles

1. Biceps. The front portion of the upper ami for bending of the arm at the elbow.
2. Triceps. Back of upper arm for straightening of ami at the elbow.
3. Biceps femoris. Back of thigh for bending leg at the knee.
4. Quadriceps. Front of thigh
5. Gluteus maximus. Buttocks.
6. Gastrocnemius. Calves, bending of the ankle joint.
7. Frontal. Fore-head.
8. Orbicularis oculi. Closure of eyes.
9. Orbicularis oris. Closure of mouth.
10. Masseter. Mastication.
11. Trapezius. Upper back and side of the neck
12. Deltoid. Shoulder raises an arm.
13. Pectoralis major. Lowers arm.

NEET Biology Muscular System Notes

NEET Biology Kingdom Protista Features Of Muscle Fibers

• Excitability. The skeletal muscle fibres can be excited by the nerve impulses generated in the motor nerve fibre by the specific stimuli. This power is maximum in striated muscle fibres.
• Conductivity. The skeletal muscle fibres can conduct the excitation along the length of muscle fibres at the rate of 3-5 metres/second with the help of the T-tubule system and sarcoplasmic reticulum.
• All or None Rule (Bowditch’s Law). When the skeletal muscle fibre is stimulated, it responds either by shortening or lengthening. The response of a muscle fibre is independent of the strength of the stimulus. If there is any response, it is maximum.
• The minimum strength of stimulus (nerve impulse) required to bring about the response, is called threshold stimulus. It varies from fibre to fibre. If the stimulus is of a strength below the threshold stimulus, the muscle fibre is not excited, but if the stimulus has a strength equal to or higher than the threshold stimulus, the muscle fibre shows a maximum response.
• The force of contraction does not increase with the increase in the strength of the stimulus. But in the case of whole muscle, the extent of contraction depends upon the number of motor units which are contracting at any particular period.

NEET Biology Kingdom Protista Useful Terms

1. Latent phase or period. It is a brief time interval between the point of stimulation and the actual starting of response i.e. contraction phase. The duration of the latent period varies with the species, type of muscle, temperature and internal condition of the muscle.

• It is due to the time taken for the propagation of impulse from the point of stimulation to the” neuromuscular junction and then to sarcolemma  for initiation of contraction (In frogs it lasts about 10 milliseconds in skeletal muscles and up to 3 sec. in visceral muscles.)

1. Contraction phase. It is the time interval in which the muscle reaches the peak of contraction and performs work. (It lasts for 40 milliseconds in skeletal and 20 sec. in visceral muscles.)
2. Relaxation phase. It is the longest of three phases. It lasts about 50 milliseconds in skeletal muscles, and 2.3 sec in visceral muscles and is indicated by downward tracing in the kymograph (graph showing a twitch contraction). During the phase, the muscle returns to its original length.
3. Single Muscle Twitch. The response of a muscle to a single short stimulus, such as 1 electric shock is known as a twitch and can be recorded as a kymograph. A twitch can be divided into three successive phases.
4. Motor unit. All muscle fibres supplied by a single motor neuron are called a motor unit. On average, there are 100 muscle fibres in a motor unit.
5. Isotonic contractions. When a muscle contracts, with a constant load that it  can lift, it is said to be isotonic contraction In other words there is a change in the shape of the muscle and it maintains tension
6. Isometric contractions. When a muscle contracts against a weight dial it cannot lift, it is called an isometric contraction. In other words, llicic is no change in the shape of the muscle. AS u maintains umfoim length.
7. Tentas. It the muscle fibre is stimulated before it relaxes for a second time, it can contract again If we continue closely spaced stimuli, we gel a smooth sustained contraction, called a tetanus or tetanic contraction.
8. Summation. If a second stimulus is applied to a muscle that is still in the contraction phase, a second contraction is added to die first and results in greater shortening of muscle than caused by a single stimulation. It is termed summation.
9. Refractory period. (0.002 – 0.005 see in skeletal, 0.1-02 sec in cardiac muscle fibre.) If two stimuli are applied one immediately after the other, die muscle will respond to the first stimulus, but not to the second.
   1. The brief period during which the muscle does not respond to the second stimulus is called a refractory period or period of lost irritability. Its duration varies with the muscle involved. Skeletal muscle has a short refractory period w whereas cardiac muscle has a long refractory period.
   2. The absolute refractory period during which the recovering muscle fibre cannot be stimulated by a stimulus of any strength.
   3. The relative refractory period during which the muscle fibre can be excited only by a stimulus of strength higher than the previous strength of the stimulus.
10. Fatigue. If muscle fibres are repeatedly stimulated to contract, these fibres take a longer time to respond to the excitation during contraction and also to complete relaxation.
11. Their force of contraction also declines progressively. Finally, the fibres fail to contract at all for some time. It is known as muscle fatigue. It is caused by the accumulation of lactic acid and other changes in the muscle due to prolonged contraction.
12. Site of muscle fatigue. Stephens and Taylor suggested that the site of skeletal muscle fatigue is the neuro-muscular junction and occurs when there is increased K⁺ concentration and decreased Na+ concentration in the ECF of the muscle fibres.
13. Rigor mortis. Muscles become stiff after death. This state is called rigor mortis. It occurs due to the absence of ATP. It first appears in the muscles of the face and jaw. Rigour mortis disappears after three or four days because the proteins become soluble.
14. Red muscle fibres contain myoglobin, arc thin, dark red and contain mitochondria. These are capable of doing more work and do not easily get tired.
15. White muscle fibres are of light red or pink and do not contain myoglobin and mitochondria. Get easily tired and cannot work for long.

NEET Biology Kingdom Protista Muscle Contraction (Sliding Filament Theory)

1. The sequence of myosin-actin bonding, sliding and release is repeated rapidly over and over until the muscle has shortened sufficiently. This is the sliding fuming mechanism for muscle contraction, and it consumes a great deal of ATP.
2. When an individual muscle is stimulated, the actin filament in every sarcomere unit slides towards the middle of the sarcomere. As a result, the myofibrils shorten. A muscle cell shortens (contracts) then all its myofibrils shorten. An entire muscle contracts when many of its muscle cells contract simultaneously.
3. Contraction ends when the muscle cell ceases to be stimulated by the nerve cell. If an impulse no longer travels down the T – tubules to the cell’s interior, Ca2+ is actively transported back into the SR.
4. Without Ca2+, the troponin-tropomyosin protein complex shifts back into its original position, masking the sites on the actin filaments and preventing further bonding by the myosin heads. When this happens, the muscle relaxes and returns to its original shape.

NEET Biology Kingdom Protista Biochemical Aspects

1. During contraction actin and myosin combine to form actomyosin, this was shown in vitro by Szent Gyorgi (1946), who won the Nobel Prize for this work.
2. There are three basic pathways for providing energy to be utilised in muscle contraction.
3. The hydrolysis of ATP provides free energy to the converted to mechanical energy by the interaction of actin and myosin. Here myosin plays the role of ATPase.
4. ADP + CP + H⁺ → ADP + Pi + H⁺ ΔG
5. The ATP molecule present in muscle cells lasts for only a few seconds of muscle action. Hence muscle mainly depends upon other phosphate molecules creatine phosphate (CP) as a source of energy stored it. This acts as a recharger of ADP. ADP + CP + H⁺ →ATP + C (Lohmann’s Reaction)
6. This reaction was discovered by Lohmann (1932) which won him a Nobel Prize.
7. After the CP of reserve is exhausted muscle resorts to glycolysis of glycogen. Whose end product is the lactic acid that causes fatigue.
8. Oxygen debt. Till the entire amount of creatine phosphate is recovered through the regeneration of ATP by oxidative phosphorylation body remains in oxygen debt and to repay it the person keeps on panting after a strenuous exercise. Cori cycle. The accumulated lactic acid diffuses out of muscle through blood and reaches the liver where it is reconverted to glycogen.
9. Troponin and Tropomyosin are two regulatory proteins present on this filament and are essential for the actin-myosin interaction i.e., muscle contraction.

1. When during muscle contraction, muscle length remains c& the same but tension increases then it is called isometric contraction For Example Holding some weight.
2. When during muscle contraction, muscle length changes but tension remains constant then it is called isotonic contraction For Example during walking. c& Glycogen can be formed more readily from glucose in muscles.
3. Carl Ferdinand Cori shared the 1947 Nobel Prize for physiology and medicine with his wife Gerty Theresa Cori and B.A. Houssary for their work on the metabolism of glycogen.
4. Animals with“liquid skeleton”-Earthworms, Caterpillars (larvae of butterflies and silk moths), and Slugs. It gives shape and support to the body. c& In the case of non-chordates except echinoderms arginine is present in place of phosphocreatine.
5. Sarcomere functional unit of contraction of a muscle.
6. All or none law is also known as Bowditch’s law.  Biochemical and electrical events during muscle contraction were studied by Albert Szent Gyorgi Special conducting system of the heart consists of special cardiac muscle fibres.
7. Treppe (Staircase phenomenon) A stimulus of constant strength applied regularly at clock intervals to a muscle produces a series of contractions, the first of which are of increasing amplitude.
8. Glycogenolysis occurs in liver cells but not in muscle cells as these lack the Glucose-6 phosphatase enzyme. Troponin-Tropomyosin Complex prevents muscle contraction as it inhibits the activity of ATPase enzyme and prevents the formation of actomyosin complexes., Oxygen-Debt. Amount of extra oxygen consumed during the recovery after an exercise.
9. Shivering involves the involuntary contraction of voluntary muscle fibres.
10. 30-40 % of energy is used in contraction and the rest is converted into heat. This helps in warming the body.
11. Roles of Muscle and Bones in Movement The force generated by muscle contraction pulls or lifts bone through tendons. Movement occurs along the joint, hence the bone actually acts as a lever having 3 parts :
12. In the body joint acts as F, point of attachment of muscle to bone is E.
13. There are 3 classes of levers:
14. 1st class lever. F comes between E and R, very rare in the body, one such example is the head resting on the vertebral column.
15. 2nd class lever. R comes between F and E, only a few in the body, For Example, raising the body on the toes.
16. 3rd class lever. E remains in between the F and R, the most common type of lever in the body For Example, flexing the forearm at the elbow joint.

NEET Biology Muscular System Notes

NEET Biology Kingdom Protista Questions From Competitive Examinations

Question 1. Immediate Source Of Energy For Muscle Contraction  Is:

1. Glucose
2. Gtp
3. Creatine Phosphate
4. ATP

Answer: 4. ATP

Question 2.  Which One Yields ATP Required For Muscle Contraction?

1. Myoglobin
2. Creatine Phosphate
3. Creatinine Phosphate
4. Myosin.

Answer: 2. Creatine Phosphate

Question 3. Edta Injected Into Muscles Combines With Ca₂⁺ And :

1. Stops Contraction
2. Causes Contraction
3. Slows Down Contraction
4. None Of The Above.

Answer: 1. Stops Contraction

Question 4. What Is Sarcomere?

1. Part Between Two H-Line
2. Part Between Two A-Line
3. Part Between Two I-Band
4. Part Between Two Z-Iine.

Answer: 4. Part Between Two Z-Iine.

Question 5. Which Statement Is Correct For Muscle Contraction?

1. Length Of H-Zone Becomes Decreased
2. Length Of A-Band Remains Constant
3. Length Of I-Band Becomes Increased
4. Length Of Two Z-Line Become Increase,

Answer: 1. Length Of H-Zone Becomes Decreased

Types of Muscles NEET

Question 6. Which light band Contains The following fluid protein?

1. Myosin
2. Actin
3. Both 1 & 2
4. None Of These.

Answer: 2. Actin

Question 7. Largest Skeletal Muscle Is Present In :

1. Thigh
2. Neck
3. Arm
4. Belly.

Answer: 1. Thigh

Question 8. Hinge Joint Is Present In :

1. Elbow
2. Pivot
3. Interphalangeal
4. Atlas.

Answer: 1. Elbow

Question 9. Biceps & Triceps Are Found In :

1. Fore Arm
2. Upper Arm
3. Thigh
4. Shoulder.

Answer: 2. Upper Arm

Question 10. Actin Filaments Depolymerise And Repolymerise In Motile Cells With :

1. 0.2 – 0.3 Millisecond
2. 1.0 – 2.0 Minutes
3. 1 – 2 Hours
4. 2-3 Days.

Answer: 1. 0.2 – 0.3 Millisecond

Question 11. Sacromere Occurs Between :

1. Z – Line To Z – Line
2. Two I – Bands
3. Two Surfaces Of A Z – Line
4. Two A – Bands.

Answer: 1. Z – Line To Z – Line

Question 12. “All Or None Law” Is Not Associated With.

1. Muscle Fibre
2. Tiruiun
3. Cardiac Muscle
4. Uriniferous Tubules

Answer: 4. Uriniferous Tubules

Question 13. ATPase Enzyme  Needed For Muscle Contraction Is Located In :

1. Myosin
2. Actin
3. Actinin
4. Troponin.

Answer: 1. Myosin

Types of Muscles NEET

Question 14. Which Of The Following Is Important For Muscle Contraction And Nerve Impulse Transmission?

1. Ca_2⁺ Ions
2. Ca⁺⁺ And Mg⁺⁺ Ions
3. Mg⁺ ₄– Ions
4. Fe _2⁺ Ions.

Answer: 2. Ca⁺⁺ And Mg⁺⁺ Ions

Question 15. During Strenuous Exercise Glucose Is Converted Into :

1. Glycogen
2. Pyruvic Acid
3. Starch
4. Lactic Acid.

Answer: 4. Lactic Acid.

Skeletal Muscle Structure NEET

Question 16. Which Of The Following Is Not Syncytial?

1. Cardiac Muscle
2. Skeletal Muscle
3. Smooth Muscle
4. Interstitial Muscle.

Answer: 3. Smooth Muscle

Question 17. The Condition In Which A Number Of Nuclei Are Present In A Muscle Fibre Is Called :

1. Coenocytic
2. Syncytial
3. Polykaryon
4. Endoduplicaton.

Answer: 2. Syncytial

Question 18. Contractile Tissues Have The Following Features :

A. Mesodermal In Orign

B. They Contain Stretch Receptors.

C. Rhythmic Contractions Are Seen In Them

D. Hey Do Not Fatigue During The Life Of The Animal.

Which Of The Above Are Characteristics Of Sphincters?

1. All The Four
2. Only A, B And C
3. Only A, B And D
4. Only A, C And D.

Answer: 2. Only A, B And C

Question 19. The Lactic Acid Generated During Muscle Contraction Is Converted To Glycogen In :

1. Muscle
2. Kidney
3. Pancreas
4. Liver.

Answer: 2. cAMP

Question 20. In Heart Cells, Which One Serves As A Second Messenger, Speeding Up Muscle Cell Contraction In Response To Adrenaline?

1. cAMP
2. cGMP
3. GTP
4. ATP
5. AMP.

Answer: 1. cAMP

Skeletal Muscle Structure NEET

Question 21. The Contractile Protein Of Skeletal Muscle Involving Atpase Activity Is :

1. Troponin
2. A-Actin
3. Tropomyosin
4. Myosin.

Answer: 4. Myosin.

Question 22. The Globular Protein Molecule, Which Masks The Active Sites On The F-Actin Is :

1. Troponin
2. Myosin
3. Tropomyosin
4. Light Mbromyosin
5. Heavy Meromyosin.

Answer: 1. Troponin

Question 23. Statements :

1. A-Bands Of The Muscle Is Dark And Contain Myosin
2. I-Hamls Air The Light Hands Ami Contain Actin
3. During Muscle Contraction The A-band Contracts
4. The Part Between The Two Z-Lines Is Called As Sacromere
5. The Central Pan Of Thin Filament, Not Overlapped By Thick Filament Is Called H-Zone.

Of The Above Statements.

1. 1, 3, and 5 Are Correct While 2 And 4 Are Incorrect
2. 1, 2, 3 And 3 Are Correct While 4 Is Incorrect
3. 1, 2 And 3 Are Correct While 4 And 3 Are Incorrect
4. 1, 2 And 4 Are Correct While 3 And 3 Are Incorrect
5. 1 And 2 Are Correct While 3, 4 And 5 Are Incorrect.

Answer: 4. 1, 2 And 4 Are Correct While 3 And 3 Are Incorrect

Question 24. All Or None Law Is Not Applicable To :

1. Whole Skeletal Muscle
2. Single Skeletal Muscle Fibre
3. Whole Cardiac Muscle
4. Single Smooth Muscle Fibre.

Answer: 1. Whole Skeletal Muscle

Question 25. The H-Zonc In The Skeletal Muscle Fibre Is Due To :

1. The Central Gap Between Myosin Filaments In The A-Band.
2. The Central Gap Between Actin Filaments Extending  Through Myosin Filaments In The A Band.
3. Extension Of Myosin Filaments In The Central Portion Of The A-Band.
4. The Absence Of Myofibrils In The Central Portion Of A-Band.

Answer: 2. The Central Gap Between Actin Filaments Extending  Through Myosin Filaments In The A Band.