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Plant Anatomy Question From Competitive Examinations

Question 1. In floating leaved plants, stomata occur on:

1. Lower surface
2. Upper surface
3. Both sides
4. Absent.

Answer: 2. Upper surface

plant anatomy mcqs

Question 2. Vascular bundles occur in a ring in:

1. Monocot stem
2. Leaf
3. Root
4. Dicot stems.

Answer: 4. Dicot stem.

Question 3. A.T.S. of the stem is stained first with safranin and then fast green. What would be the colour of the phloem?

1. Red
2. Green
3. Orange
4. Purple.

Answer: 2. Green

anatomy of flowering plants

Question 4. Passage cells occur in:

1. Epidermis
2. Cortex
3. Endodermis
4. Pericycle.

Answer: 3. Endodermis

Question 5. Casparian strips occur in:

1. Longitudinal and radial walls of epidermal cells
2. Longitudinal walls of xylem
3. All walls of endodermis
4. Radial walls of endodermis.

Answer: 4. Radial walls of endodermis.

morphology of flowering plants mcq class 11

Question 6. Loading of phloem is related to:

1. Increase of sugar in phloem
2. Elongation of phloem cell
3. Separation of phloem parenchyma
4. Strengthening of phloem fibre.

Answer: 1. Increase of sugar in phloem

Question 7. Roots of which plant contain a red pigment which has an affinity for oxygen:

1. Canon
2. Soyabean
3. Mustard
4. Radish.

Answer: 2. Soyabean

Question 8. In the monocot root, we observe:

1. Conjoint, collateral, closed, polyarch vascular bundle
2. Exodermis, end arch, and tetrarch closed bundles
3. Suberized exodermis, Casparian strip, passage cells cambium
4. Suberized exodermis, polyarch xylem, pith.

Answer: 4. Suberized exodermis, polyarch xylem, pith.

Question 9. Dead cells that serve mechanical functions are:

1. Sclerenchyma
2. Companion cells
3. Collenchyma
4. Wood parenchyma.

Answer: 1. Sclerenchyma

Question 10. Annual rings are found in plants belonging to:

1. Arabic region
2. Temperate areas
3. Tropics
4. Near sea beaches.

Answer: 2. Temperate areas

Question 11. ‘Histogen theory’ was proposed by:

1. Hanstein
2. Eamu
3. Esmam
4. Schmidt.

Answer: 1. Hanstein

Question 12. In the diagram of the T.S. of Helianthus stem given below, certain parts have been indicated by alphabets; choose the answer in which these alphabets have been correctly matched with the parts which they 

1. A = Epidermis, B = Epidermal hairs
   C = Parenchyma, D = Starch sheath
   E = Hypodermis (collenchyma),
   F = Vascular bundle
   G = Bundle cap, H = Medulla or pith
   I = Pith
2. A = Epidermis hairs, B = Epidermis
   C = Hypodermis (Collenchyma),
   D = Parenchyma
   E = Starch sheath, F = Bundle cap
   G = Vascular bundle, H = Medullary rays.
   I = Medullary rays
3. A = Epidermal hairs, B = Epidermis
   C = Hypodermis (collenchyma),
   D = Starch sheath, E = Parenchyrna,
   F = Vascular bundle, G = Bundle cap,
   H = Medulla or pith, I = Medullary rays.
4. A = Epidermal hairs, B = Epidermis
   C = Parenchyma, D = Hypodermis (Collenchyrnil)
   E = starch sheath, F = Vascular bundle
   G = Bundle cap, H = Medulla or pith
   I = Medullary rays
5. C = Hypodermis (Collenchyma),
   D = Parenchyma
   E = Starch sheath, F = Bundle cap
   G = Vascular bundle, H = Medullary rays.
   I = Medullary rays

Answer: 2. A = Epidermis hairs, B = Epidermis

Question 13. In the diagram of the cross-section of the vascular bundle of the monocot stem given aside, different parts have been indicated by alphabets; choose the answer in which these alphabets have been correctly matched with the parts which they indicate

morphology of flowering plants class 11 mcq

1. A = Bundle sheath, B = Broken phloem,
   C = Metaphloem, D = Metaxylem,
   E = Protoxylem, F = xylem parenchyma,
   G = Lysigenous cavity
2. A = Bundle cap, B = Metaphloem,
   C = Protophloem, D = Protoxylem,
   E = Metaxylefit, F = Lysigenous cavity,
   G = Xylem parenchyma
3. A = Bundle sheath, B = Primary phloem,
   C = Secondary phloem, D = Primary xylem,
   E = secondary xylem, F = Xylem fibres,
   G = Hydathode
4. A = Bundle cap, B = Metaxylem,
   C = Metaphloem, D = Protoxylem,
   E = Protophloem, F = Lysigenous cavity,
   G = Xylem parenchyma.

Answer: 1. A = Bundle sheath, B = Broken phloem,
C = Metaphloem, D = Metaxylem,
E = Protoxylem, F = xylem parenchyma,
G = Lysigenous cavity

Question 14. Match the names of the structures listed under column-1 with the functions given under column 2. Choose the answer which gives the correct combination of the alphabet of the two columns:

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

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

Question 15. Match the types of vascular bundles listed under Column 1 with examples given under Column 2; choose the answer which gives the correct combination of the alphabets of the two columns:

1. 1=D, 2=C, 3=B, 4=A
2. 1=D, 2=C, 3=A, 4=B
3. 1=t, 2=D, 3=C, 4=A
4. 1=D, 2=A, 3=C, 4=B

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

Question 16. Terminal and axillary buds arise from:

1. Apical meristem
2. Parenchyma
3. Lateral meristem
4. Intercalary meristem.

Answer: 1. Apical meristem

Question 17. Intercalary meristem is located in:

1. Latex
2. Root
3. Stem tip
4. Petiole and internode.

Answer: 4. Petiole and internode.

Question 18. Which of the following is not a component:

1. Vascular rays
2. Medullary rays.
3. Vessels
4. Tracheids.

Answer: 2. Medullary rays.

Question 19. The primary cell wall is elastic due to the absence of:

1. Suberin
2. Culin
3. Pectin
4. Lignin.

Answer: 4. Lignin.

Question 20. Vessels are found in:

1. All angiosperms
2. Most angiosperms, a few gymnosperms and pteridophytes.
3. All angiosperms and a few gymnosperms
4. Most angiosperms and a few gymnosperms.

Answer: 2. Most angiosperms, a few gymnosperms and pteridophytes.

Question 21. Four radial vascular bundles are formed in:

1. Monocot root
2. Dicot stem
3. Dicot root
4. Monocot stem.

Answer: 3. Dicot root

Question 22. Annual rings are formed basically due to:

1. Marked variations in seasons
2. Different kinds of development of phloem and xylem
3. Uniform climate conditions
4. Different kinds of phloem.

Answer: 1. Marked variations in seasons

Question 23. The commercial use fibres are obtained from:

1. Interxylary fibres
2. Xylem fibres
3. Phloem fibres
4. None of these.

Answer: 3. Phloem fibres

Question 24. Which one of the following tissues does not possess living protoplasm?

1. Collenchyma
2. Sclerenchyma
3. Tracheids
4. Parenchyma.

Answer: 2. Sclerenchyma

Question 25. The chief function of the sieve tube element is:

1. To translocate the organic materials from source to sink
2. To conduct minerals
3. To conduct water from roots to leaves
4. To help the plants in forming wood.

Answer: 1. To translocate the organic materials from source to sink

Question 26. Cambium activity is highest in:

1. Spring
2. Winter
3. Autumn
4. Rains.

Answer: 1. Spring

Question 27. In the leaf, vascular bundles are found in

1. Veins
2. Palisade tissue
3. Upper epidermis
4. Lower epidermis
5. Spongy mesophyll.

Answer: 1. Veins

Question 28. The quiescent centre in the root meristem series is a

1. Site for storage of food which is utilized during maturation
2. Reservoir of growth hormones
3. Reserve for replenishment of damaged calls of the meristem
4. Region for absorption of water.

Answer: 3. Reserve for replenishment of damaged calls of the meristem

Question 29. In a dicotyledonous stem, the sequence of tissues from the outside to the inside is:

1. Phellem – Pericycle – Endodermis – phloem
2. Phellem – Phloem – Endodermis – Pericycle
3. Phellem – Endodermis – Pericycle – Phloem
4. Pericycle – Phellem – Endodermis – Phloem.

Answer: 3. Phellem – Endodermis – Pericycle – Phloem

Question 30. Jute fibres deteriorate because they have:

1. High cellulose
2. Low cellulose
3. High lignin
4. Low lignin.

Answer: 3. High lignin

Question 31. Wood is:

• Primary xylem
• Secondary xylem
• Primary phloem
• Secondary phloem.

Answer: 2. Secondary xylem

Question 32. Cork cambium results in the formation of cork which becomes impermeable to water due to the accumulation of:

1. Resins
2. Suberin
3. Lignins
4. Tannins.

Answer: 2. Suberin

Question 33. Companion cells in plants are associated with:

1. Vessels
2. Sperms
3. Guard cells
4. Sieve elements.

Answer: 4. Sieve elements.

Question 34. In a plant organ which is covered by periderm and in which the stomata are absent, some gaseous exchange will take place through:

1. Lenticels
2. Trichomes
3. Aerenchyma
4. Pneumatophores

Answer: 1. Lenticels

Question 35. In a woody dicotyledonous tree, which of the following parts will mainly consist of primary tissues?

1. Stem and root
2. All parts
3. Shoot tips and root tips
4. Flowers, fruits and leaves.

Answer: 3. Shoot tips and root tips

Question 36. Which of the following statements is not true?

1. Cork cambium is otherwise called phellogen
2. Cork is otherwise called Phellem
3. The secondary cortex is otherwise called the periderm
4. The Cork cambium, cork and secondary cortex are collectively called Phelloderm

1. 3 and 4 only
2. 1 and 2 only
3. 2 and 3 only
4. 2 and 4 only
5. 1 and 4 only.

Answer: 1. 3 and 4 only

Question 37. Bicollateral conjoint vascular bundles have

1. Xylem and phloem, which are arranged alternately on different radii
2. The xylem and phloem, are situated at the same radius and it has two groups of phloem along the two sides of the xylem (inside and outside)
3. Xylem and phloem in the same radius but it has only one group phloem outside the xylem
4. Phloem surrounds the xylem tissues xylem surrounds the Phloem tissues.

Answer: 2. The Xylem and phloem, are situated at the same radius and it has two groups of phloem along the two sides of the xylem (inside and outside)

Question 38. Math the following in column 1 with column 2 and choose the correct combination.

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

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

Question 39. Casparian thickenings are found in the cells of:

1. Pericycle of the root
2. Endodermis of the root
3. Pericycle of the stem
4. Endoermis of the stem.

Answer: 2. Endodermis of the root

Question 40. A portion of apical meristem that gives rise to xylem tissue is called:

1. Protoxylem
2. Metaxylem
3. Procambium
4. Tracheid

Answer: 3. Procambium

Question 41. For a critical study of secondary growth in plants, which one of the following pairs is suitable?

1. Teak and pine
2. Deodar and fern
3. Wheat and maidenhair fern
4. Sugarcane and sunflower.

Answer: 1. Teak and pine

Question 42. Passage cells are thin-walled cells found in:

1. Phloem elements serve as entry points for substances for transport to other plant parts.
2. Testa of seeds to enable the emergence of growing embryonic axis during seed germination.
3. The central region of style through which the pollen tube grows towards the ovary.
4. Endodermis of roots facilitating rapid transport of water from cortex to pericycle.

Answer: 4. Endodermis of roots facilitating rapid transport of water from cortex to pericycle.

Question 43. One of the characteristics of a sieve tube is:

1. It is a part of phloem
2. The function is the transport of inorganic solutes
3. It is a dead cell
4. A sieve plate is not present.

Answer: 1. It is a part of phloem

Question 44. In the following pairs where do you get lignin in both the elements?

1. Tracking and collenchyma
2. Sclerenchyma and sieve tube
3. Sclerenchyma and trachea
4. Parenchyma and endodermis.

Answer: 3. Sclerenchyma and trachea

Question 45. Which of the following statements is true?

1. Uneven thickening of the cell wall is characteristic of sclerenchyma
2. Periblem forms the cortex of the stem and the root
3. Tracheids are the chief water-transporting elements in gymnosperms
4. Companion cells are devoid of the nucleus at maturity
5. The commercial cork is obtained from Quercus suber

1. (1) and (4) only
2. (2) and (3) only
3. (3) and (4) only
4. (1), (2) and (3) only.
5. (2), (3) and(5).

Answer: 5. (2), (3) and(5).

Question 46. The waxy material deposited in the Casparian strip of the endodermis is:

1. Pectin
2. Suberin
3. Cellulose
4. Lignin
5. Hemicellulose.

Answer: 2. Suberin

Question 47. The vascular cambial ring of a dicot stem is:

1. Primary in origin
2. Secondary in origin
3. Embryonic in origin
4. Tertiary in origin
5. Partly primary and partly secondary in origin

Answer: 5. Partly primary and partly secondary in origin

Question 48. Consider the following statements:

1. In a dicot root, the vascular bundles are collateral and endarch
2. The innermost layer of the cortex in a dicot root is the endodermis
3. In a dicot root, the phloem classes are separated from the xylem by parenchymatous cel1s that are known as the conjunctive tissue of these statements given above

1. (1) is true, but (2) and (3) are false
2. (2) is true, but (1) and (3) are false
3. (1) is true, but (2) and (3) are false
4. (3) is true, but (1) and (3) are false
5. (3) is true, but (1) and (2) are false

Answer: 5. (3) is true, but (1) and (2) are false

Question 49. Ground tissue includes:

1. Axe tissues external to endodermis
2. All tissues except the epidermis and vascular bundles
3. Epidermis and cortex
4. All tissues are internal to the endodermis.

Answer: 2. All tissues except the epidermis and vascular bundles

Question 50. The cork cambium, cork and secondary cortex are collectively called:

1. Phelloderm
2. Phellogen
3. Periderm
4. Phellem

Answer: 3. Periderm

Question 51. The common bottle cork is a product of:

1. Pheliogen
2. Xylem
3. Vascular cambium
4. Dermatogen.

Answer: 1. Pheliogen

Question 52. Closed Vascular bundles lack:

1. Conjunctive tissue
2. Cambium
3. Pith
4. Ground tissue

Answer: 2. Cambium

Question 53. Water-containing cavities in vascular bundles are found in:

1. Maize
2. Cycas
3. Pinus
4. Sunflower.

Answer: 1. Maize

Question 54. Companion cells are closely associated with:

1. Vessel elements
2. Trichomes
3. Guard cells
4. Sieve elements.

Answer: 4. Sieve elements.

Question 55. Interfascicular cambium develops from the cells of:

1. Xylem parenchyma
2. Endodermis
3. Pericycle
4. Medullary rays.

Answer: 4. Medullary rays.

Question 56. The age of a tree can be estimated by:

1. Biomass
2. Number of annual rings
3. Diameter of its heartwood
4. Its height and girth

Answer: 2. Number of annual rings

Class 12 Biology Evolution

Question 1. Mechanical isolation in plants is illustrated with an example of:

1. Oxalis
2. Ficus
3. Salvia
4. Calotropis.

Answer: 4. Calotropis.

Question 2. Speciation in two adjacent populations refers to;

1. Sympatry
2. Allopatry
3. Population isolation
4. Parapatric speciation.

Answer: 4. Parapatric speciation.

Question 3. Which of the following is not a part of Lamarck’s theory of evolution?

1. Use and disuse of organ
2. Variation
3. Inheritance of acquired characters
4. Environmental effect.

Answer: 2. Variation

Question 4. Who wrote the famous book “Philosophie Zoologique.”

1. Darwin
2. Morgan
3. Wallace
4. J. Lamarck.

Answer: 4. J. Lamarck.

Question 5. According to Darwin, the different populations of the same species are referred to as:

1. Varieties
2. Subspecies
3. Cultivars
4. Incipient species.

Answer: 3. Cultivars

evolution mcq

Question 6. Acquired characters are inherited. Which of the following scientists did not support the idea?

1. T.H. Morgan
2. A. Weismann
3. T.H. Huxley
4. De Vries.

Answer: 2. A. Weismann

Question 7. A staunch supporter of Neo-Lamarckism is:

1. A. Weismann
2. T.H. Morgan
3. C. Darwin
4. Hugo de Vries.

Answer: 2. T.H. Morgan

Question 8. Darwin’s theory of natural selection:

1. Was the first theory of evolution
2. Failed to explain the sources of evolution
3. Account for fossils
4. Has been replaced completely.

Answer: 2. Failed to explain the sources of evolution

Question 9. The concept of evolution through natural selection remains incomplete without:

1. Variations
2. Survival of fittest
3. Struggle for existence
4. All the above.

Answer: 4. All the above.

Question 10. Who performed famous inbreeding experiments to expose the inefficiency of Darwinism?

1. Johanson
2. Dobzhansky
3. Sympson
4. Ernst Myar.

Answer: 1. Johanson

Question 11. Adaptive radiation is:

1. Migration from centres of dispersal
2. Tlic use of radioactive isotopes in biological research
3. Radiation used to destroy cancer
4. Evolution from an ancestral type to a diverse form suited to different environments.

Answer: 4. Evolution from an ancestral type to a diverse form suited to different environments.

Question 12. Two different groups evolve in such a way so as to produce similar traits. This is an example of:

1. Parallel evolution
2. Divergent evolution
3. Convergent evolution
4. Both (2) and (3).

Answer: 3. Convergent evolution

Question 13. Marine arthropods were preadapted to terrestrial life by having:

1. No coelom
2. Exoskeleton
3. Closed circulatory system
4. No body segmentation.

Answer: 2. Exoskeleton

Question 14. Reproductive isolation between segments of a single population is termed:

1. Allopatry
2. Population
3. Divergence sympatry
4. Disruptive isolation.

Answer: 3. Divergence sympatry

Question 15. “An organ is used well, it will develop better and if it is not used, it is likely to become vestigial”. This was given by:

1. Darwin
2. De Vries
3. Lamarck
4. Mendel.

Answer: 3. Lamarck

Question 16. Blood precipitation tests are useful in:

1. Blood group
2. Animal relation
3. Antigen-antibody reaction
4. Immunity.

Answer: 2. Animal relation

evolution class 12 mcq

Question 17. Fitness, according to Darwin refers ultimately to:

1. Dominance over others
2. Ability to defend
3. Number of offsprings
4. Strategy for obtaining food.

Answer: 3. Number of offsprings

Question 18. Nowadays Lamarckian theory is being reviewed in the light of the modern concept of evolution under the heading Neo-Lamarckism. Who proved that the genes are influenced by physical and chemical factors so that they bring remarkable changes to the offspring:

1. Muller
2. Lindsci
3. Hoffman
4. Haeckel.

Answer: 1. Muller

Question 19. The struggle for existence is a consequence of:

1. Innate competitive tendencies
2. Territories and dominance hierarchies
3. Each organism leaves behind more offspring than needed to replace it
4. The inevitable difficulty of coping with climatic conditions.

Answer: 4. The inevitable difficulty of coping with climatic conditions.

Question 20. When in the nucleus of some animal cell the number of chromosomes is increased or decreased, and a change takes place in the genes, then the event is called:

1. Hereditary characters
2. Adaptation
3. Mutation
4. None.

Answer: 3. Mutation

Question 21. In convergent evolution:

1. Unrelated organisms look alike under environmental influence
2. Related organisms look distinct
3. The similarity in appearance is not caused by environmental factors
4. The environment has no role.

Answer: 1. Unrelated organisms look alike under environmental influence

Question 22. The aspect most profoundly coupled with natural selection is:

1. Preservation of favoured races
2. Adaptability of every single species
3. Enhanced fecundity of all organisms
4. Lesser role of environmental factors.

Answer: 1. Preservation of favoured races

Question 23. The modem scientific theory is redefined:

1. Natural selection
2. Theory of natural selection
3. Theory of special creation
4. Scala Naturae.

Answer: 2. Theory of natural selection

Question 24. Natural selection acts on an organism:

1. Dominant alleles
2. Recessive homozygous alleles
3. Combined genotype
4. Phenotype.

Answer: 4. Phenotype.

Question 25. Microevolution concerns the occurrence of:

1. Tribes
2. Races
3. Sub-species
4. Genera.

Answer: 3. Sub-species

Question 26. Microevolution changes:

1. Genetic equilibrium
2. Dominant trait
3. Gene pool
4. Gene occurrence.

Answer: 1. Genetic equilibrium

Question 27. Neo-Darwinism believes that new species develop through:

1. Mutations
2. Hybridisation
3. Mutations with natural selection
4. Continuous variations with natural selection.

Answer: 3. Mutations with natural selection

Question 28. The two key concepts of Darwinian theory of evolution are:

1. Fitness
2. Branching descent
3. Natural selection
4. Both (2) and (3).

Answer: 4. Both (2) and (3).

Question 29. Distantly related organisms with similar traits have experienced:

1. Co-evolution
2. Convergent evolution
3. Divergent evolution
4. Parallel evolution.

Answer: 2. Convergent evolution

Question 30. “Darwin’s theory of Natural Selection” was objected to, because it:

1. Stresses open inter-specific competition
2. Explains adaptations of certain inherited characters
3. Stresses upon slow and small variations.
4. Explains that natural calamities take a heavy annual toll on lives.

Answer: 3. Stresses upon slow and small variations.

Question 31. Parallelism is:

1. Adaptive divergence in evolution
2. Adaptive convergence of widely different species in evolution
3. Adaptive convergence of closely related species in evolution
4. None of the above.

Answer: 3. Adaptive convergence of closely related species in evolution

Question 32. The Hardy-Weinberg Law states that when two alleles are considered:

1. Dominant alleles will always be more frequent in the population than recessive alleles
2. Heterozygotes will be twice as likely as homozygotes in a population
3. Members of adjacent populations are not able to interbreed with one another
4. Allelic frequencies cannot change in a large population unless one is at a selective advantage over the other or mating is non-random.

Answer: 4. Allelic frequencies cannot change in a large population unless one is at a selective advantage over the other or mating is non-random.

Question 33. The Hardy-Weinberg Law allows us to predict that:

1. Sexual reproduction is necessary for evolution
2. Sexual reproduction may be a cause of evolution
3. Sexual reproduction plays no role in evolution
4. Sexual reproduction will cause evolution if individuals prefer mates with one genotype over those with other genotypes.

Answer: 4. Sexual reproduction will cause evolution if individuals prefer mates with one genotype over those with other genotypes.

Question 34. The change of lighter coloured variety of peppered moth, Riston betularia to its darker variety (carbonara) is due to:

1. Mutation of a single Mendelian gene for survival in the smoke-laden industrial environment
2. Deletion of a segment of a gene due to industrial pollution
3. Industrial carbon deposited on the wings of moths results in the darker variety
4. Translocation of a block of genes in chromosomes in response to heavy carbons.

Answer: 1. Mutation of a single Mendelian gene for survival in the smoke-laden industrial environment

Question 35. In evolution, change mutation occurs in:

1. Protoplasm
2. Germplasm DNA
3. RNA
4. Nucleus.

Answer: 2. Germplasm DNA

Question 36. Genetic drift is most important in which situation?

1. Gene flow in a cline
2. Polymorphism
3. Small populations
4. Breeding of flying insects.

Answer: 3. Small populations

Question 37. Genetic drift is more likely to cause evolution in a small population because:

1. Mating is non-random in small populations
2. Random events are more apt to happen in small populations
3. There is no natural selection in small populations
4. Deviations from statistical averages are more likely to be seen in small populations than in large ones.

Answer: 4. Deviations from statistical averages are more likely to be seen in small populations than in large ones.

Question 38. Selection will not eliminate a lethal recessive allele from a large population of diploid organisms because:

1. There will always be some heterozygote carrier for the allele
2. Gene fixation will occur in the population
3. Hetcrozygotcs arc at a selective advantage
4. The allele will have some good effects and these will become dominant.

Answer: 1. There will always be some heterozygote carrier for the allele

Question 39. The most likely reason for the development of resistance against pesticides in insect-damaging crops is:

1. Genetic recombination
2. Acquired heritable changes
3. Directed mutations
4. Random mutations.

Answer: 2. Acquired heritable changes

Question 40. The theory of Neo-Lamarckism is dependent on:

1. Mutation and natural selection
2. Mutation
3. Variation
4. Heredity.

Answer: 1. Mutation and natural selection

Enzymes Multiple Choice Question and Answers

Question 1. The enzymes that break up starch into sugar are called:

1. Hydrolase
2. Amylase
3. Lipase
4. Nucleases.

Answer: 2. Amylase

Question 2. Enzymes are named after their substrate by adding a suffix:

1. – In
2. – Ase
3. – Os
4. – Sin.

Answer: 2. – Ase

Question 3. Apoenzyme is :

1. Protein
2. Carbohydrates
3. Vitamin
4. Amino acid.

Answer: 1. Protein

Question 4. Co-enzyme is :

1. Always a protein
2. Always a vitamin
3. Often a vitamin
4. Often a protein

Answer: 3. Often a vitamin

Question 5. The rate of most of the enzyme-catalyzed reactions changes with pH. As the pH increases, this rate:

1. Reaches a maximum then decreases
2. Reaches a minimum then decreases
3. Increases
4. Decreases.

Answer: 1. Reaches a maximum then decreases

Question 6. Co-enzymes can function :

1. In association with an apoenzyme
2. Independently of the apoenzyme
3. In association with vitamin
4. In association with a protein.

Answer: 1. In association with an apoenzyme

carbohydrates questions

Question 7. The enzymes which break up nucleic acids into nucleotides are called:

1. Nucleases
2. Amylases
3. Lipase
4. Protease.

Answer: 1. Nucleases

Question 8. Which mineral element is essential for the activity of enzyme nitrate reductase:

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

Answer: 1. Molybdenum

Question 9. Most vitamins function as :

1. Holoenzyme
2. Enzymes
3. Hormones
4. Co-enzymes

Answer: 4. Co-enzymes

Question 10. Stoppage of the biochemical process by the product of a step is known as:

1. Negative inhibition
2. Endproductinhibition
3. Feedback inhibition
4. All of the above

Answer: 4. All of the above

Question 11. Which of the following is the best evidence for the lock and key theory of enzyme action?

1. A11 isolated enzymes have been identified as proteins
2. Compounds similar in structure to the substrate inhibit the reaction
3. Enzymes are found in living organisms and speed up certain reactions
4. Enzymes determine the direction of a reaction

Answer: 2. Compounds similar in structure to the substrate inhibits the reaction

Question 12. Enzymes generally have :

1. Same pH and temperature options
2. Same pH but different temperature options
3. Different pH but same temperature optima
4. Different pH and different temperature optima

Answer: 3. Different pH but same temperature optima

Question 13. The term feedback refers to

1. The effect of substrate on the rate of enzymatic reaction
2. The effect of end product on the rate of enzymatic reaction
3. The effect of enzyme concentration or its rate of reaction
4. The effect of an external compound on the rate of enzymatic reaction.

Answer: 2. The effect of the end product on the rate of enzymatic reaction

Question 14. Near the freezing point, an enzyme is :

1. Killed
2. Slightliz activated
3. Inactivated
4. Unaltected

Answer: 3. Inactivated

Question 15. Which of the following statements is true about enzymes?

1. Is altered permanently in the reaction it catalyses
2. Lowers the energy of activation of a reaction
3. Makes the equilibrium n-lore favorable for the organism
4. Lowers the energy of the product and increases the energy of the reactant.

Answer: 2. Lowers the energy of activation of a reaction

protein parts of enzyme is known as 

Question 16. Enzymes, vitamins, and hormones have one thing in common:

1. Au is synthesized in organisms
2. All are proteins
3. Al1 aids in regulating metabolism
4. All enhance oxidative metabolism.

Answer: 3. Al1 aids in regulating metabolism

Question 17. Which energy is needed to digest food reserves in castor seeds?

1. Lipase
2. Proteases
3. Amylase
4. Lactase.

Answer: 1. Lipase

Question 18. Which of the following is the best evidence for the template theory of enzyme action?

1. Compounds similar in structure to the substrate inhibit the reaction
2. Enzymes speed up the reactions by definite amounts
3. Enzymes determine the direction of a reaction
4. Enzymes are found in living organisms and increase the rate of certain reactions.

Answer: 1. Compounds similar in structure to the substrate inhibits the reaction

Question 19. Nitrate reductase enzyme forms :

1. N₂
2. Amino acids
3. NO¯²
4. NO‾³

Answer: 3. NO-2

Question 20. In plants enzymes are present :

1. Only in flowers
2. Only in leaves
3. In all the living cells of the plant body
4. Only in storage organ.

Answer: 3. In a1l the living cells of the plant body

Question 21. Which of the following lacks enzymes?

1. Algae
2. Fungi
3. Bacteria
4. Virus.

Answer: 4. Virus.

Question 22. In the cell, digestive enzymes are mostly in :

1. Ysosornes
2. Cel1wal1
3. Ribosomes
4. Chromosome.

Answer: 1. Ysosornes

Question 23. Which of the following is iron-porphyrin complex?

1. Cytochrome
2. Fad
3. Co-a
4. Nad

Answer: 1. Cytochrome

Question 24. Fad or fmn is a co-enzyme. Which vitamin is incorporated into its structure?

1. Vitamin c
2. Vitamin B1
3. Vitamin B6
4. Vitamin B2

Answer: 4. Vitamin B.

Question 25. The ratio of the enzyme to the substrate molecule can be as high as:

1. 1: 1000
2. 1: 100,000
3. 1: 1000,000
4. 1: 50,000.

Answer: 3. 1: 1000,000

questions on carbohydrates

Question 26. Lock and key hypothesis to explain the action of enzymatic action was given by :

1. Kogl
2. Fischer
3. Miller
4. Lederberg and Tatum.

Answer: 2. Fischer

Question 27. Enzymes with the same function and different molecular structures are called:

1. Isomerases
2. Zymases
3. Isoenzymes
4. Coenzymes.

Answer: 3. Isoenzymes

Question 28. The enzyme that removes the hydrogen from a substrate is:

1. Decarboxylase
2. Dehydrogenase
3. Protease
4. Lipase.

Answer: 2. Dehydrogenase

Question 29. Which of the following is not true for enzymes?

1. Colloidal nature
2. Used up in the biochemical reaction
3. Affected by the change in temperature
4. Lowers the activation energy.

Answer: 2. Used up in the biochemical reaction

Question 30. Zyrnogen is defined as :

1. An enzyme inhibitor
2. Highly reactive state of the enzyme
3. An inactive proenzyme.
4. Complex formed of enzyme and substrate

Answer: 3. An inactive proenzyme.

Question 31. Which of the following enzymes would change glucose-6 phosphate to glucose 1-phosphate?

1. Transferase
2. Isomerase
3. Lyases
4. Glucose phosphatases.

Answer: 2. Isomerase

Question 32. Maximum enzyme activity is observed at :

1. Acidic ph
2. Neutral ph
3. Basic ph
4. Optimum ph.

Answer: 4. Optimum ph.

Question 33. Conversion of pepsinogen into pepsin is :

1. Intramolecular rearrangement
2. Breaking of hydrogen bonds
3. Covalent modifications
4. Polymerization

Answer: 3. Covalent modifications

Question 34. The following reaction is characteristic of what type of enzyme?

1. Peroxidases
2. Catalases
3. Dehydrogenases
4. Copper-containing oxidases.

Answer: 1. Peroxidases

Question 35. Number of substrate molecules changed per minute by a molecule of the enzyme is called:

1. Reaction index
2. Turn over number
3. Deficiency number
4. Optimum number.

Answer: 2. Turn over number

Question 36. During the enzyme action:

1. The value of k is low
2. The value of k1 is low
3. The value of k- is high
4. The value of k, is high.

Answer: 2. Value of k1 is low

Question 37. Oxidative enzymes mostly occur in :

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

Answer: 2. Mitochondria

Question 38. The substrate concentration at which half of the maximum velocity is achieved is termed :

1. Sumner’s constant
2. Michaelis constant
3. Buchner constant
4. Fischer constant.

Answer: 2. Michaelis constant

Question 39. An enzyme brings about :

1. Reduction in activation energy
2. Increase in reaction time
3. Increase in activation energy
4. All the above.

Answer: 1. Reduction in activation energy

Question 40. Enzymes exist in the cells as :

1. Solid
2. Crystals
3. Colloid
4. None of the above.

Answer: 3. Colloid

Question 1. The Nerve Fibres that conduct Impulses From The Peripheral To The Central Nervous System Are Called :

1. Motor Nerve Fibres
2. Mixed Nerve Fibres
3. Afferent Nerve Fibres
4. Efferent Nerve Fibres.

Answer: 3. Afferent Nerve Fibres

Question 2. The Nerve Fibres that carry Impulses From The Central Nervous System To The Muscles And Glands For Contraction And Secretion Are Called:

1. Efferent Nerve Fibres
2. Afferent Nerve Fibres
3. Mixed Nerve Fibres
4. Sensory Nerve Fibres.

Answer: 1. Efferent Nerve Fibres

nervous system questions

Question 3. When Sympathetic System Acts On A Particular Organ, Its Action Is :

1. Stimulated
2. Inhibited
3. Transmitted
4. Regulated.

Answer: 4. Regulated.

Question 4. The Simplest Form Of Nervous System That integrates rates of Body Activities Is Found In Cnidarians And Called :

1. Nerve Trunk System
2. Nerve Net System
3. Ladder System
4. Nerve Cord System.

Answer: 2. Nerve Net System

questions about nervous system

Question 5. Excitability And Conductivity Are The Outstanding Properties Of:

1. Arteries
2. Veins
3. Neurons
4. Nephrons.

Answer: 3. Neurons

Question 6. Dendrites Transmit The Impulses To :

1. The Body Of Cell
2. The Neurilemma
3. The Myelin Sheath
4. The Axon Only.

Answer: 1. The Body Of Cell

Question 7. Resting Potential Of Nerve Cells Is :

1. -90 Mv
2. -70-90 Mv
3. -120 Mv
4. -60 M V.

Answer: 2.  -70-90 Mv

Question 8. Nerve Is:

1. Group Of Nerve Fibres Bounded Together By Connective Tissue
2. Group Of Nerve Fibres Bounded By A Membrane
3. A Group Of Neuron Only
4. None Of The Above.

Answer: 2. Group Of Nerve Fibres Bounded By A Membrane

questions about the nervous system

Question 9. Myelinated Fibres Are Nerve Fibres that are:

1. Without Any Surrounding Sheath
2. With A Surrounding Sheath
3. Without Axon
4. None Of The Above.

Answer: 2. With A Surrounding Sheath

Question 10. During Synaptic Transmission Of Nerve Impulse, Neurotransmitter (P) Is Released From Synaptic Vesicles By The Action Of Ions (Q). Choose The Correct P And Q.

1. P = Acetylcholine, Q = Ca^–+
2. P = Acetylcholine Q = Na⁺
3. P = Gaba, Q =Na⁺
4. P = Cholinesterase, Q = Ca⁺⁺.

Answer: 3. P = Gaba, Q =Na+

Question 11. The Transmission Of Nerve Impulse Is A :

1. Mechanical Process
2. Biological Process
3. Electrochemical Process
4. Physical Process.

Answer: 3. Electrochemical Process

Question 12. The Potential Difference’betwecn Inside And Outside Of A Neuron Before Excitation Is Known As :

1. Resting Potential
2. Action Potential
3. Spike Potential
4. Reaction Potential.

Answer: 1. Resting Potential

Question 13. What Is The Difference Between The Conduction Of Electricity Through An Electric wire And That Of Nerve Impulse Through A nerve fibre

1. Nerves Are Living
2. Electricity Provides A Shock
3. Nerve Impulse Is Sell Generated On Stimulation And Propagated
4. All The Above.

Answer: 3. Nerve Impulse Is Sell Generated On Stimulation And Propagated

central nervous system test

Question 14. When Nene Is Stimulated, It Is Polarized. DepolarizaTion Is Maintained By The Following Ion :

1. Ca⁺⁺
2. Cl^–
3. Mg⁺⁺
4. Organic Compounds, K⁺ And Na⁺.

Answer: 4. Organic Compounds, K⁺ And Na⁺.

Question 15. During Resting Conditions The Membrane Of the Axon Is :

1. Impermeable To Na⁺ And K⁺ Ions
2. Permeable To Both Na⁺ And K⁺ Ions
3. More Penncable To K⁺ Than Na⁺ Ions
4. More Permeable To K⁺ And Cl^– Ions.

Answer: 3. More Penncable To K⁺ Than Na⁺ Ions

Question 16. The Tire Part Of Ommatidium That Is Functionally Similar To the Retina Is :

1. Crystalline Cone
2. Basement Membrane
3. Rhabdome
4. Vitrellae.

Answer: 3. Rhabdome

nervous system test

Question 17. The Simplest Form Of Nerve Network Is :

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

Answer: 2. Reflex Arc

Question 18. The Chemical Theory Of Transmission Attributes The Response Of Postsynaptic Cells To A Chemical Substance Released From:

1. Axon
2. Synapse
3. Pre-Synaptic Nerve Terminal
4. Dendrites.

Answer: 3. Pre-Synaptic Nerve Terminal

Question 19. Acetylcholine Is Most Closely Associated With Which Of The Following Systems?

1. Autonomic Nervous System
2. All The Neurons Except Those Of Sympathetic Nervous System
3. Parasympathetic Nervous System
4. Peripheral Nervous System.

Answer: 2. A11 The Neurons Except Those Of Sympathetic Nervous System

Question 20. The Sensory Ganglion Concerned With Spinal Reflex Lies In:

1. Anterior Root Of Spinal Nerve
2. Anterior Hom Of Spinal Nerve
3. Posterior Root Of Spinal Nerve
4. Posterior Hom Of Spinal Cord.

Answer: 3. Posterior Root Of Spinal Nerve

Question 21. Sodium Pump Of An Axon Is Operative At:

1. Action Potential Period
2. Resting Potential Period
3. Refractory Period
4. None Of The Above.

Answer: 1. Action Potential Period

Question 22. The Gap Between the Terminal Knobs Of An Axon And Dendrites Of The Cell Body Of Another Axon Is Known As:

1. Synaptic Cleft
2. Synapse
3. Neural Crest
4. Tight Junction.

Answer: 1. Synaptic Cleft

Question 23. Acetylcholine Is :

1. Secreted  By Nerve Cells In Synapse
2. Produced By Liver
3. A Delivery Enzyme
4. Activates Enzymes.

Answer: 1. Produced By Liver

Question 24. Action Potential Is :

1. Brief Change In Electric Charge
2. Brief Change In Oxygen Concentration
3. Brief Change In C0₂ Concentration
4. Change In Direction Of Nerve.

Answer: 1. Brief Change In Electric Charge

Question 25. During the Refractory Period :

1. Nerve Transmits Impulses Rapidly
2. Nerve Transmits Impulses Very Slowly
3. Nerve Never Transmits Impulses
4. None Of The Above.

Answer: 3. Nerve Never Transmits Impulses

Question 26. Electrical Impulse Of The Eye Recorded Are :

1. Encephalogram
2. Electro-Cardiogram
3. Electro-Retinogram
4. None Of The Above.

Answer: 3. Electro-Retinogram

Question 27. Neurotransmitters Are Compounds That:

1. Help In Transmission Of Impulse In Synapse
2. Retard The Transmission Of Impulse In An Axon
3. Retard The Transmission Of Impulse At Synapsis
4. None Of The Above.

Answer: 1. Help In Transmission Of Impulse In Synapse

Question 28. The 3rd, 6th And 11th Cranial Nerves Are :

1. Oculomotor, Trigeminal, Spinal
2. Optic, Facial, Spinal
3. Oculomotor, Abducens, Spinal
4. Trochlear, Abducens, Vagus.

Answer: 3. Oculomotor, Abducens, Spinal

Question 29. Which Of The Following Cranial Nerves Is Present In Rabbit But Absent In Frog?

1. Glossopharyngeal
2. Hypoglossal
3. Olfactory
4. Optic

Answer: 2. Olfactory

Question 30. Nervous System Was, First Of All, Originated In :

1. Leech
2. Ascaris
3. Hydra
4. Tape Worm.

Answer: 3. Hydra

Question 31. Sympathetic Nerves In Mammals Arise From :

1. Thoraco-Lumbar Nerves
2. 3^rd, 7^th, 9^th And 10^th Cranial Nerves
3. Sacral Nerves
4. Cervical Nerves.

Answer: 1. Thoraco-Lumbar Nerves

Question 32. At The Nerve Synapse :

1. Carbon Dioxide Is Released
2. Oxygen Is Released
3. Neuro-Transmitters Are Released
4. Nothing Is Released.

Answer: 3. Neuro-Transmitters Are Released

Question 33. At The Nerve Cell Membrane, The Equilibrium Potential For Potassium Is :

1. + 65 M V
2. +35m V
3. -90 M V
4. -70 M V

Answer: 3. -90 M V

Question 34. The “Spike” Phase Of Action Potential Lasts For Roughly :

1. 20 Milli Second
2. 2 Milli Second
3. 200 Milli Second
4. 2000 Milli Second.

Answer: 2. 2 Milli Second

Question 35.The Chemical Thcoiy Of Ti.Msmissiou Iillrilnitcs The Response Of Postsvnaptic Coll To A Chemical Substance Released Item :

1. Axon
2. Synapse
3. Pre-Synaptic Nerve Terminal
4. Dendrites.

Answer: 3. Pre-Synaptic Nerve Terminal

Question 36. One None Is Stimulated, It Is Polarized. Depolarization Is Maintained By The Following Ion :

1. Ca⁺
2. Cl^–
3. Mg⁺⁺
4. K⁺.

Answer: 4. K⁺.

Question 37. During Resting Conditions The Membrane Of the Axon Is:

1. Impermeable To Na⁺ And K⁺ Ion
2. Permeable To Both Na⁺ And K⁺ Ions
3. More Penncable To K⁺ Than Na⁺ Ion
4. More Permeable To K⁺ And Cl^– Ions.

Answer: 3. More Penncable To K⁺ Than Na⁺ Ion

Question 38. Conduction Of Nerve Impulse Along A Myelinated Nerve Is :

1. Twisted
2. Reversible
3. Saltatory
4. Continuous.

Answer: 3. Saltatory

Question 39. Somaesthetic Area Is Located In :

1. Frontal Lobe
2. Mid Lobe
3. Parietal Lobe
4. None.

Answer: 3. Parietal Lobe

Question 40. The Ends Of Bipolar Neurons In Retina Of Man Touch :

1. Choroid Layer And Ganglion Cells
2. Photosensitive Cells And Ganglion Cells
3. Cornea And Retina
4. Blind Spot And Yellow Spot.

Answer: 2. Photosensitive Cells And Ganglion Cells

Question 41. Glands Of Swammerdam Are Rich In :

1. Calcium
2. Acetylcholine
3. Dopamine
4. Gonadotrophin.

Answer: 1. Calcium

Question 42. Sensory Neuron In A Vertebrate Reflex Are Located In :

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

Answer: 4. Dorsal Root Ganglion.

Question 43. Which One Of The Following Nerves Is Not Related To The Movement Of Eye Ball?

1. Oculomotor
2. Abducens
3. Trochlear
4. Glossopharyngeal.

Answer: 4. Glossopharyngeal.

Question 44. The Benzodiazepine Drug Known As Valium Produces Relaxation By Aiding The Binding To Receptor Proteins Of Inhibitory Neurotransmitters:

1. Ach
2. Gaba
3. Dopamine
4. Glycine.

Answer: 2. Gaba

Question 45. Which One Of The Following Is The Effect Of Parasympathetic Nervous System?

1. Increasing Blood Pressure
2. Secretion Of Digestive Juice
3. Dilating Pupil
4. Increasing Cardiac Output.

Answer: 2. Secretion Of Digestive Juice

Question 46. Which Of The Following Is the Function Of Pons Varolii?

1. Site Of Cardiac Centre
2. Perceiving Centre For Crude Sensation
3. Controls Hunger And Thirst
4. Transmits Impulses From One Side Of Ceubellum To The Other Side.

Answer: 4. Transmits Impulses From One Side Of Ceubellum To The Other Side.

Question 47. The Cervical Plexus Is Formed By

1. Anterior Rami Of First Two Cervical Nerves
2. Anterior Rami Of First Three Cervical Nerves
3. Anterior Rami Of First Two Cervical And First Two Thoracic Nerves
4. Anterior Rami Of Hist Four Cervical Nerves.

Answer: 4. Anterior Rami Of First Two Cervical And First Two Thoracic Nerves

Question 48. Presynaptic Membrane Permits :

1. Influx Of Na⁺ Ions
2. Influx Of Ca^+₃  Ions
3. Influx Of Na⁺ And K⁺ Ions
4. Start Of Original Impulse.

Answer: 2. Influx Of Ca^+₂ Ions

Question 49. Heart Beat Is Regulated By :

1. Cns
2. Ans
3. PNS
4. Spinal Cord.

Answer: 2. Ans

Question 50. Brain Reserves How Many Percent Of Total 0₂ Consumed By Body?

1. 10%
2. 20%
3. 30%
4. 40%.

Answer: 2. 20%

Question 51. The Refractory Centre Which Rfor Exampleulates Respiration Is Located In :

1. Medulla Oblongata
2. Cerebral Peduncle
3. Vagus Nerve
4. Cerebellum.

Answer: 1. Medulla Oblongata

Question 52. Which Brain Structure In Rabbit Is Directly Vision Related ?’

1. Hippocampus
2. Corpus Callosum
3. Corpus Albicans
4. Corpora Quadrigeminum.

Answer: 4. Corpora Quadrigeminum

Question 53. Most Of The Neurons Of Our Body Are :

1. Unipolar
2. Bipolar
3. Pseudo-Unipolar
4. Multipolar.

Answer: 4. Multipolar.

Question 54. Body Coordination Is Exhibited By :

1. Blood Vascular System
2. Nervous System
3. Endocrine System
4. Nervous And Endocrine System.

Answer: 4. Nervous And Endocrine System.

Question 55. The Sodium-Potassium Pump :

1. Transports Na⁺ And K⁺ Out Of The Neuron
2. Transports Na⁺ Into The Neuron And K⁺ Out
3. Transports K⁺ Into The Neuron And Na⁺ Out
4. Transports Na⁺ And K⁺ Into The Neuron.

Answer: 3. Transports K⁺ Into The Neuron And Na⁺ Out

Question 56. When A Neuron Shows A Stable Resting Potential, The Concentration Of Na⁺ Is :

1. 10 Times Higher Inside The Cell Than Outside
2. 10 Times Higher Outside The Cell Than Inside
3. 30 Times Higher Inside The Cell Than Outside
4. 30 Times Higher Outside The Cell Than Inside.

Answer: 2. 10 Times Higher Outside The Cell Than Inside

Question 57. In The Resting State Of The Neural Membrane, Diffusion Due To Concentration Gradients, If Allowed, Would Drive

1. Na⁺ Into The Cell
2. Na⁺ Out Of The Cell
3. K⁺ Into The Cell
4. K⁺ And Na⁺ Out Of The Cell.

Answer: 1. Na⁺ Into The Cell

Question 58. The Resting Potential Of Neurons Is  70 Mv. It Is Mainly Due To :

1. Excess Of Chloride Ions Inside
2. Excess Of Protein Ions Inside
3. Na+ Ions Outside
4. K⁺ Ions Inside.

Answer: 3. Na⁺ Ions Outside

Question 59. A Nerve Impulse Which Travels Through Nerve Fibre Only It Its Membrane Suddenly Becomes More Permeable To Ions Of:

1. Chloride
2. Potassium (K⁺)
3. Sodium (Na⁺)
4. Magnesium (Mg⁺⁺).

Answer: 3. Sodium (Na⁺)

Question 60. An Action Potential, For A Given Axon, Is:

1. Different In Size Each Time It Occurs
2. Always The Same Size
3. Larger When Information Has To Be Conveyed Faster
4. Smaller When Information Goes To A Gland Rather Than  A Muscle.

Answer: 2. Always The Same Size

Question 61. Which Of The Following Increases When An Action Potential Is Initiated?

1. Diffusion Of Sodium Ions Into The Neuron
2. Diffusion Of Sodium Ions Out Of The Neuron
3. Diffusion Of Potassium Ions Out Of The Neuron
4. Diffusion Of Potassium Ions Into The Neuron.

Answer: 1. Diffusion Of Sodium Ions Into The Neuron

Question 62. When An Action Potential Abruptly Drops From Positive To Nfor Exampleative, This Is Because :

1. Potassium Gates Are Inactivated And Sodium Gates Are Opened
2. Sodium Gates Are Inactivated And Potassium Gates Are Opened
3. Both Potassium And Sodium Gates Are Inactivated
4. Both Potassium And Sodium Gates Are Opened.

Answer: 2. Sodium Gates Are Inactivated And Potassium Gates Are Opened

Question 63. A Nerve Impulse Leaves A Neuron Via :

1. Dendrite
2. Cyton
3. Axon
4. Nucleus.

Answer: 3. Axon

Question 64. Synapse Is A Gap Between Adjacent :

1. Muscle Fibres
2. Nerve Cells
3. Nerve Cell Bodies
4. None Of The Above.

Answer: 2. Nerve Cells

Question 65. A Nerve Which Conveys Impulses From A Tissue To Nerve Centre Is Called :

1. Efferent
2. Mixed
3. Motor
4. Afferent.

Answer: 4. Afferent.

Question 66. The “Spike” Phase Of The Action Potential Lasts For Roughly :

1. 2 Milliseconds
2. 20 Milliseconds
3. 200 Milliseconds
4. 2000 Milliseconds.

Answer: 1. 2 Milliseconds

Question 67. The Speed At Which Impulses Are Conducted Increases With :

1. Increasing the Diameter Of The Soma
2. Increasing the Diameter Of The Axon
3. Increasing Number Of Dendrites
4. Increasing Branching Of The Dendrites.

Answer: 2. Increasing the Diameter Of The Axon

Question 68. Saltatory Conduction Of Nerve Impulses Occurs In :

1. A myelinated Fibres
2. Myelinated Fibres
3. Both A And B
4. None Of The Above.

Answer: 2. Myelinated Fibres

Question 69. Synaptic Fatigue Is Due To :

1. Exhaustion Of Neurotransmitter
2. Release Of More Adrenaline
3. Release Of More Acetylcholine
4. None Of The Above.

Answer: 1. Exhaustion Of Neurotransmitter

Question 70. Secretion Of Parasympathetic Nerve Endings Is :

1. Noradrenaline
2. Glycine
3. Acetylcholine
4. Hydroxy-Triptamine.

Answer: 3. Acetylcholine