Class 12 Biology

• Organisms and Populations Class 12 Biology MCQs
• Evidence Of Evolution Relationship Among Organisms MCQS
• Evolution Of Man Multiple Choice Questions

• Origin of Life Multiple Choice Questions
• Enzymes Multiple Choice Questions
•  Elements Of Heredity And Variations Multiple Choice Questions
• Evolution Multiple Choice Questions

Evidence Of Evolution Relationship Among Organisms Question and Answers

Question 1. Match the names of the persons listed under Column A with the contributions given in Column B; choose the choice which gives the correct combination of the alphabet:

1. 1 = r, 2 = t, 3 = p, 4 = q.
2. 1 = t, 2 = r, 3 = q,4 = p.
3. 1 = p, 2 = q, 3 = r, 4 = s.
4. 1 = r, 2 = p, 3 = t, 4 = q.

Answer: 4. 1 = r, 2 = p, 3 = t, 4 = q.

Read and Learn More 12th Class Biology MCQs

Question 2. Which one is not vestigial in humans?

1. Third molar
2. Coccyx
3. Segmental abdominal muscles
4. Finger nails.

Answer: 4. Fingernails.

Question 3. Coal has been mainly formed by:

1. Bryophytes
2. Pteridophytes/pteridosperms
3. Angiosperms
4. Algae.

Answer: 2. Pteridophytes/pteridosperms

PSEB 12th Class Biology Evidence of Evolution MCQs

Question 4. Darwin’s finches provide evidence of evolution from:

1. Anatomy
2. Morphology
3. Biogeography
4. All the above.

Answer: 3. Biogeography

Question 5. The vestigial pelvic girdle and bone remnants of hind limbs are characteristic of:

1. Whale
2. Dolphin
3. Shark
4. Seal.

Answer: 1. Whale

Question 6. Monkeys and some lower groups have certain blood groups which are:

1. Identical to those of man
2. Identical to those of anthropoid apes
3. Somewhat similar to white persons
4. Not identical to those of man.

Answer: 1. Identical to those of man

Question 7. The heart is four-chambered in:

1. Amphibia
2. Fishes
3. Mammals
4. Reptiles.

Answer: 3. Mammals

Question 8. A living organism with the oldest fossil history is:

1. Dinosaur
2. Archaeopteryx
3. Horse
4. Man.

Answer: 3. Horse

Question 9. Homologous organs are:

1. Human eyes and Squid eyes
2. Gills of Fish and lungs of Man.
3. Hands of Man and Wings of Bat
4. Leaf of Moss and a frond of Fern.

Answer: 3. Hands of Man and wings of Bat

Question 10. The occurrence of endemic species in South America and Australia is due to

1. These species have been extinct in other regions
2. Continental separation
3. There is no terrestrial route to these places
4. Retrogressive evolution.

Answer: 2. Continental separation

Evidence of Evolution Relationship Among Organisms MCQs PSEB Class 12

Question 11. Similarities in organisms with different genotypes indicates:

1. Microevolution
2. Macroevolution
3. Convergent evolution
4. Divergent evolution

Answer: 2. Macroevolution

Question 12. Convergent evolution is illustrated by:

1. Dogfish and whale
2. Rat and dog
3. Bacterium and protozoan
4. Starfish and cuttlefish.

Answer: 1. Dogfish and whale

Question 13. Which one of the following is categorized under living fossils?

1. Metasequoia
2. Ficus
3. Cycas
4. Selaginella.

Answer: 3. Cycas

Question 14. In which branch do we study about remains of plant life?

1. Palaeontology
2. Palaeobotany
3. Eugenics
4. Palynology.

Answer: 2. Palaeobotany

Question 15. Flippers of the seal are modified:

1. Hind limbs
2. Forelimbs
3. Fins
4. Gills.

Answer: 2. Forelimbs

Question 16. A baby was born with a small tail. It is a case of exhibiting:

1. Retrogressive evolution
2. Atavism
3. Mutation
4. Metamorphosis.

Answer: 2. Atavism

Question 17. Which of the following is a living fossil?

1. Saccharomyces
2. Spirogyra
3. Cycas
4. Moss.

Answer: 3. Cycas

Question 18. The age of fossils in the past was determined by the radioactive carbon method and other methods involving radioactive elements found in the rocks. More precise methods, which were used recently and led to the revision of evolutionary periods from different groups of organisms:

1. Electron spin resonance and fossil DNA
2. Study of carbohydrates/proteins in the rocks
3. Study of carbohydrates/proteins in the fossils
4. Study of conditions of fossilization.

Answer: 1. Electron spin resonance and fossil DNA

Class 12 Biology Chapter Evidence of Evolution MCQs

Question 19. Potato and sweet potato have edible parts which are:

1. Analogous
2. Homologous
3. Recent introductions
4. Two species of the same genus.

Answer: 1. Analogous

Question 20. Which of the following is not a vestigial organ in humans?

1. Ear pinna muscles
2. Nictitating membrane
3. Mammary glands in males
4. Knee bone.

Answer: 4. Knee bone.

Question 21. Trilobites evolved during:

1. Silurian
2. Cambrian
3. Precambrian
4. Devonian.

Answer: 2. Cambrian

Question 22. Which of the following is not vestigial in humans?

1. Coccyx
2. Nail
3. Third molar
4. Segmental muscles of the abdomen.

Answer: 2. Nail

Question 23. Which of these pairs is vestigial?

1. Coccyx and car pinna muscles
2. Coccyx ana premolar
3. Facial hair in ladies
4. Coccyx and intercostal muslces.

Answer: 1. Cococyx and car pinna muscles

Class 12 Biology Chapter Evidence of Evolution MCQs

Question 24. Which of the following points towards common ancestry?

1. Eye of octopus and of mammal
2. Vertibsate hearts
3. Atavism
4. All of above

Answer: 4. All of the above

Question 25. The eyes of the octopus and the eyes of the cat show different patterns of structure, yet they perform similar functions. This is an example of:

1. Analogous organs that have evolved due to convergent evolution
2. Homologous organs that have evolved due to divergent evolution.
3. Analogous organs that have evolved due to divergent evolution.
4. Homologous organs that have evolved due to convergent evolution.

Answer: 1. Analogous organs that have evolved due to convergent evolution

Question 26. Which of the following is the relatively most accurate method for dating of fossils?

1. Uranium-lead method
2. Potassium-argon method
3. Electron-spin resonance method
4. Radiocarbon method.

Answer: 3. Electron-spin resonance method

Question 27. The evolutionary history of an organism is known as:

1. Palaeontology
2. Ontogeny
3. Phylogeny
4. Ancestry.

Answer: 3. Phylogeny

Question 28. Which one of the following is not a living fossil?

1. Archaeopteryx
2. King crab
3. Peripatus
4. Sphenodon.

Answer: 1. Archaeopteryx

Question 29. An important evidence in favour of organic evolution is the occurrence of:

1. Homologous organs only
2. Homologous and analogous organs
3. Analogous and vestigial organs
4. Homologous and vestigial organs.

Answer: 2. Homologous and analogous organs

Question 30. The age of fossils or dating of fossils can be best estimated by:

1. Radioactive carbon (C¹⁴) dating method
2. Radioactive clock method
3. Potassium-argon method
4. None of the above.

Answer: 1. Radioactive carbon (C¹⁴) dating method

PSEB 12th Class Biology Evolution MCQs with Answers

Question 31. The example which best explains the atavism is:

1. Nictitating membrane
2. Wisdom teeth
3. Vermiform appendix
4. Long thick and dense hair.

Answer: 4. Long thick and dense hair.

Question 32. Which of the following gives the correct evidence from the connecting link?

1. Ornithorhynchus — Between Amphibia and Reptiles
2. Baltuwglossus — Between Protozoa and Porifera
3. Neopilinct — Between MolluscaandEchinodcrmata
4. Peripatus — Between Annelida and Arthropoda.

Answer: 4. Peripatus — Between Annelida and Arthropoda.

Question 33. Jurassic period of the Mesozoic era is characterised by

1. Dinosaurs become extinct and angiosperms appear
2. Flowering plants and the first dinosaurs appear
3. Gymnosperms arc dominant plants and the first birds appear
4. Radiation of reptiles and origin of mammal-like reptiles.

Answer: 3. Gymnosperms arc dominant plants and the first birds appear

Question 34. Which one of the following statements is correct?

1. There is no evidence of the existence of gills during embryogenesis of mammals
2. All plant and animal cells are totipotent
3. Ontogeny repeats phylogeny
4. Stem cells are specialized cells.

Answer: 3. Ontogeny repeats phylogeny

Question 35. The Finches of Galapagos islands provide an evidence in favour of:

1. Evolution due to Mutation
2. Retrogressive Evolution
3. Biogeographical Evolution
4. Special Creation.

Answer: 3. Biogeographical Evolution

Question 36. When two species of different genealogy come to resemble each other as a result of adaptation, the phenomenon is termed:

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

Answer: 3. Convergent evolution

Question 37. Myrmecobius and Myrmecophaga are closely related and have similar adaptations for the same habitat. This phenomenon is

1. Homoplasy
2. Parallel evolution
3. Divergent evolution
4. Convergent evolution.

Answer: 2. Parallel evolution

PSEB 12th Class Biology Evolution MCQs with Answers

Question 38. Which one of the following options gives one correct example of convergent evolution and divergent evolution?

Answer: 4

Question 1. A rapidly growing population experiences increasing genetic variability because:

1. There is a greater chance for polymorphism in large populations
2. The mutation rate is higher for large populations
3. There is less selective pressure
4. A large population can support more genetic experimentation
5. Heterozygote superiority is selectively favoured.

Answer: 4. Heterozygote superiority is selectively favoured.

Question 2. When food is distributed in such a way that an animal must spend a large part of its day wandering from one place to another to find enough to eat, what type of mating system would you expect it to have?

1. Monogamy
2. Polyandry
3. Polygamy
4. Polygyny.

Answer: 3. Polygamy

Question 3. A human male who remains a bachelor is most likely to enhance his evolutionary success by altruistic behaviour towards the children of:

1. His sister
2. His brother
3. His mother
4. His grandmother.

Answer: 3. His mother

Read and Learn More 12th Class Biology MCQs

Question 4. In light of the definition of evolution, which of the following is not capable of evolving?

1. A population of deer
2. The colour of a population of moths
3. Your biology teacher
4. The millions of bacteria in your large intestine.

Answer: 3. Your biology teacher

PSEB Solutions Class 12 Biology Evolution MCQs

Question 5. Which of the following did Kettlewell conclude from his studies on industrial melanism in moths?

1. A dark moth lays more eggs than a light moth in industrial areas
2. Dark moths are more resistant to pollution than are light moths
3. Pollution caused some moths to become darker than others
4. Dark moths are more likely to survive in polluted areas than light moths.

Answer: 4. Dark moths are more likely to survive in polluted areas than light moths.

Question 6. Which bird is most evolutionarily successful

1. Lays 9 eggs, 8 Hatch and 2 reproduce
2. Lays 2 eggs, 2 hatches and 2 reproduce
3. Lays 9 eggs, 9 hatches and 2 reproduce
4. Lays 7 eggs, 5 hatches and 4 reproduce.

Answer: 4. Lays 7 eggs, 5 hatches and 4 reproduce.

Question 7. Suppose that you have a pack of 50 assorted dogs. You select the largest male and the largest female from the group, mate them, and sterilize the other members of the pack. Assuming that food supplies remain adequate, you should expect that, in the next generation of dogs:

1. The young dogs will be, on average, larger than their two parents
2. The young dogs will be, on average, larger than the older members of the pack
3. The young dogs will be the same average size as the older dogs
4. All of the young dogs will be larger than the older dogs.

Answer: 2. The young dogs will be, on average, larger than the older members of the pack

Question 8. What is petrification?

1. Evolution of pteridophytes
2. Decay of nitrogenous materials by bacteria
3. A process of fossil formation
4. Origin of birds from reptiles.

Answer: 3. A process of fossil formation

Question 9. The main dictates of Lamarck’s theory is/are:

1. All the mentioned below
2. Effect of environment
3. Effect of use and disuse of organs.
4. Inheritance of acquired characters.

Answer: 1. All the mentioned below

Question 10. For evolutionary success, a mutation occurs in:

1. Germplasm RNA
2. Somatic DNA
3. Somatic RNA
4. Germplasm DNA.

Answer: 4. Germplasm DNA.

PSEB Solutions Class 12 Biology Evolution MCQs

Question 11. The idea of natural selection as the fundamental process of evolutionary change was reached by:

1. Charles Darwin in 1859
2. Charles Darwin and A.R. Wallace in 1859
3. C. Darwin and A.R. Wallace in 1890
4. A.R. Wallace in 1891.

Answer: 2. Charles Darwin and A.R. Wallace in 1859

Question 12. Industrial melanism is an example of:

1. Neo-Lamarckism
2. Natural selection
3. Neo-Darwinism
4. Mutation.

Answer: 2. Natural selection

Question 13. The role of mutation in evolution is:

1. Genetic drift
2. Genetic variation
3. Reproductive isolation
4. None of them.

Answer: 2. Genetic variation

Question 14. One of the following is obtained by artificial selection:

1. Kohlrabi
2. Cabbage
3. Cauliflower
4. All the above.

Answer: 1. Kohlrabi

Question 15. The frequency of a mutant gene in a population is expected to increase if the gene is:

1. Sex-linked
2. Recessive
3. Favourably selected
4. Dominant.

Answer: 3. Favourably selected

Question 16. The term isolating mechanism was coined by:

1. Duritez (1930)
2. Wagner (1868)
3. Dobzhansky (1937)
4. Blain (1941).

Answer: 3. Dobzhansky (1937)

Question 17. Who is known as the father of evolution?

1. Lamarck
2. Charles Darwin
3. Wallace
4. Erasmus Darwin.

Answer: 2. Charles Darwin

Class 12 Biology Evolution Multiple Choice Questions PSEB

Question 18. The evolution resulting in the formation of new species is known as:

1. Microevolution
2. Macroevolution
3. Both (1) and (2)
4. Mega evolution.

Answer: 2. Macroevolution

Question 19. Macroevolution operates above species level and results in the establishment of:

1. New genera
2. New Families
3. New orders
4. All of the above.

Answer: 4. All of the above.

Question 20. In speciation which of the following is most important:

1. Mutation
2. Natural selection
3. Isolation
4. All the above.

Answer: 4. All the above.

Question 21. Darwin’s finches are:

1. Water birds
2. A group of ducks occurring in the Galapagos Islands
3. Birds of the family Geospizidae
4. Birds of family Galapagos.

Answer: 3. Birds of the family Geospizidae

Question 22. Which of the following statements is false?

1. Sympatric species originate by the sudden development of reproductive isolation between segments of a species population due to sudden changes in their genotype
2. The sum total of genes of all the species in an area constitutes the gene pool.
3. The gene frequency refers to the proportion of an allele in the gene pool as compared with other alleles
4. A deme is a community of potentially interbreeding individuals at a given locality which share a single gene pool.

Answer: 2. The sum total of genes of all the species in an area constitutes the gene pool.

Question 23. Parallelism is:

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

Answer: 1. Adaptive convergence of closely related species in evolution

Question 24. Two accessory processes which contribute towards the occurrence of evolution are:

1. Migration and Inbreeding
2. Migration and hybridization
3. Migration and population mixing
4. Migration and asexual reproduction.

Answer: 2. Migration and hybridization

Question 25. _________ was the first person who considered the real meaning of fossils:

1. Aristotle
2. Anaximander
3. Francisco Redi
4. None of the above.

Answer: 2. Anaximander

Question 26. Which of the following is a matching set?

1. Survival of the fittest – Lamarck
2. Recapitulation Theory – De Vries
3. Theory of Pangenesis – Darwin
4. Use and disuse Theory – Wallace.

Answer: 3. Theory of Pangenesis – Darwin

Question 27. Class Reptilia first appears in the fossils records in:

1. Pennsylvanian period
2. Permian period
3. Cretaceous period
4. None of the above.

Answer: 1. Pennsylvanian period

Question 28. The initial appearance of reptiles from amphibian ancestors to completely terrestrial habitat is an example of:

1. Microevolution
2. Macroevolution
3. Mega evolutions
4. Speciation.

Answer: 1. Microevolution

Class 12 Biology Evolution Multiple Choice Questions PSEB

Question 29. The complete evolution of the horse has taken about:

1. 60 million years
2. 50 million years
3. 70 million years
4. 90 million years.

Answer: 3. 70 million years

Question 30. What is the essence of evolution?

1. Present-day species are the modified descendants of pre-existing ones
2. Species are changeable and mutable
3. Progressive development of simpler organisation into complex forms
4. All the above.

Answer: 4. All the above.

Question 31. In the course of evolution:

1. Reptiles have given rise to birds
2. Amphibians have given rise to reptiles
3. Ferns have given rise to gymnosperms
4. All the above.

Answer: 4. All the above.

Question 32. The concealing type of protective mimicry is associated with:

1. White crabs
2. Flat fishes
3. Pupae of Swallowtail butterfly
4. All of the above.

Answer: 4. All of the above.

Question 33. Phyllopteryx equus (Australian sea horse) shows:

1. Warning mimicry
2. Concealing mimicry
3. Both (1) and (2)
4. None of the above.

Answer: 2. Concealing mimicry

Question 34. Natural selection that favours heterozygotes is called:

1. Balancing selection
2. Heterosis
3. Progressive selection
4. Stabilizing selection.

Answer: 1. Balancing selection

Question 35. The type of selection that tends to increase the amount of variance within populations is termed:

1. Stabilizing selection
2. Frequency-dependent selection
3. Directional selection
4. Disruptive selection.

Answer: 4. Disruptive selection.

Question 36. Condensation of the phylogenetic events and the elimination of others in the embryonic development is referred to as:

1. Pathogenesis
2. Coenogenesis
3. Techygenesis
4. Ontogenesis.

Answer: 3. Techygenesis

Question 37. The theory of natural selection of Darwin was based on:

1. Variations, which are inherited, will give rise to new species
2. Good traits are preserved
3. The prodigality of reproduction, mass production of species, large number of birth rate and survival of the fittest
4. Mass conservation of mutations.

Answer: 3. Prodigality of reproduction, mass production of species, large number of birth rate and survival of the fittest

PSEB Class 12 Biology Chapter Evolution

Question 38. Persons who do hard manual work with their hands are likely to develop:

1. Greater number of sweat pores in their hands
2. A greater quantity of melanin all over the body
3. Thick subcutaneous fat in their palms
4. The thick epidermis on their palms.

Answer: 4. Thick epidermis on their palms.

Question 39. Modem synthetic theory of evolution is based on:

1. Genetic and chromosomal mutations
2. Genetic recombination and natural selection
3. Reproductive isolation
4. All of these.

Answer: 4. All of these.

Question 40. The present giraffe has a long neck as compared to its ancestors. It could be due to:

1. Isolation
2. Speciation
3. Inheritance of acquired characters
4. Natural Selection.

Answer: 4. Natural Selection.

Question 41. What is important for a species to survive in a changing environment:

1. Change in morphology.
2. Ecological variability
3. Genetic variability
4. Reproduction.

Answer: 3. Genetic variability

Question 42. The role of isolation in evolution is:

1. Differentiation of species
2. Maintenance of species
3. Extermination of species
4. Evolutionary divergence.

Answer: 1. Differentiation of species

Question 43. Being all mammals whales, dolphins, bats, and monkeys show important common characteristics but they also show conspicuous differences. This is due to the phenomenon of:

1. Normalization
2. Genetic drift
3. Convergence
4. Divergence.

Answer: 4. Divergence.

Question 44. Darwin’s theory gets much recognition because:

1. It tells about natural selection
2. It tells about the survival of the fittest
3. It is a logical sequence of events that should have occurred
4. It was proposed by an intellectual of his time.

Answer: 3. It is a logical sequence of events that should have occurred

Question 45. Birds and mammals in the geological development of earth arose in the period:

1. Permian
2. Carboniferous
3. Jurassic
4. Ordovician.

Answer: 3. Jurassic

Question 46. “Evolution can be regarded as the effect of natural selection on the continuous appearance of mutant forms.” What reason would you give to it?

1. Darwinism
2. Lamarckism
3. Neo-Darwinism
4. De Vries Mutation theory.

Answer: 3. Neo-Darwinism

PSEB Class 12 Biology Chapter Evolution

Question 47. Experimental evidence of the selection of bacteria by using the replica technique was demonstrated by:

1. Prof. A.D. Bradshaw
2. Prof. Y.D. Tyagi
3. J. Lederberg and E. Ledcrberg
4. Alfred Russel Wallace.

Answer: 3. J. Lederberg and E. Ledcrberg

Question 48. Successful adaptation means:

1. Moving to a new means
2. Producing fertile offspring
3. An increase in fitness
4. Evolving new characteristics.

Answer: 2. Producing fertile offspring

Question 49. Regarding evolution. Darwin’s explanation is that:

1. Certain species have ‘built-in’ plans of evolution
2. Those traits used most often persist longer
3. Progressive adaptations enable one species to have more offspring
4. Code determines which species should evolve.

Answer: 3. Progressive adaptations enable one species to have more offspring

Question 50. Which of the following is not inheritable?

1. Point mutation
2. Chromosomal mutation
3. Gene mutation
4. Somatic mutation.

Answer: 4. Somatic mutation.

Question 51. Organic evolution would not have taken place if:

1. Individuals in a population did not show genetic variation
2. The individual did not transmit the characteristics acquired during their lifetime to offspring
3. Somatic variations did not get inherited
4. Somatic variations did not get transformed into genetic variation.

Answer: 1. Individual in a population did not show genetic variation

Question 52. Under which of the following conditions organic evolution could not have taken place:

1. Acquired characters were not inherited
2. Somatic variations are not inherited
3. Individuals in a population did not exhibit genetic variation
4. All of them.

Answer: 3. Individuals in a population did not exhibit genetic variation

Question 53. Lederberg’s replica plating experiment suggests:

1. Characters are heritable
2. Natural selection plays an important role in fixing a mutation of survival value
3. Genes are independent entities
4. Bacteria can multiply in a culture medium.

Answer: 2. Natural selection plays an important role in fixing a mutation of survival value

Question 54. Which phenomenon of evolution was best explained by Darwin?

1. Variations occurring in a population
2. Origin of species by reproductive isolation
3. Natural selection due to the struggle for existence
4. All of these.

Answer: 3. Natural selection due to the struggle for existence

Question 55. A good example of mechanical isolation in plants is of:

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

Answer: 2. Calotropis

Question 56. The formation of high milk-yielding cows is an example of the:

1. Natural selection
2. Artificial selection
3. Survival of the fittest
4. Genetic drift.

Answer: 2. Artificial selection

Question 57. According to Goldschmidt’s classification, evolution of subspecies or geographic races is known as:

1. Mcgacvolution
2. Macroevolution
3. Microevolution
4. Speciation.

Answer: 3. Microevolution

Question 58. A scientist kept 80 generations of Drosophila in darkness, even after that the flies had normal eyes. This disapproves law of:

1. Natural selection
2. Acquired characters
3. Use and disuse
4. Synthetic theory.

Answer: 3. Use and disuse

PSEB Class 12 Biology Evolution MCQs with Answers

Question 59. Genetic drift:

1. Is an orderly change in gene frequencies
2. Produce the greatest fluctuations in large populations.
3. Is the random change in gene frequencies
4. Has nothing in common with inbreeding.

Answer: 1. Is an orderly change in gene frequencies

Question 60. Who considered that gene is the vehicle of inheritance and discontinuous variations could be inherited through genes?

1. Khorana and Nirenberg
2. Garrod and Johannsen
3. Lederberg and Tatum
4. Bateson and Morgan.

Answer: 4. Bateson and Morgan.

Question 61. Who proposed the concept of intraspecific and interspecific struggle?

1. De Vries
2. Malthus
3. Cuvier
4. Darwin.

Answer: 4. Darwin

Question 62. Which one of the following is the best example of an evolutionary change in a species of an organism?

1. Change of colour due to altered environment
2. Development of thick fur on the hare in winter
3. Alteration in the DNA structure by radiation
4. Phenotypic changes in adult Drosophila, when larval development occurs at higher than normal temperatures.

Answer: 3. Alteration in the DNA structure by radiation

Question 63. Darwinism is based on:

1. Multiplication in a geometrical progression
2. Existence of variations
3. Operation of natural selection
4. All the above.

Answer: 4. All the above.

Question 64. The convergent evolution of two species is usually associated with:

1. A recent common ancestor
2. Analogous organ
3. Homologous organ
4. Different habitat.

Answer: 2. Analogous organ

PSEB Class 12 Biology Evolution MCQs with Answers

Question 65. A detailed classification of isolating mechanisms was provided by:

1. Darwin
2. Dobzhansky
3. Wagner
4. Peterson.

Answer: 2. Dobzhansky

Question 66. The isolation caused by differences in the habits of organisms such as food and physiological requirements is called:

1. Ecological isolation
2. Ethological isolation
3. Physiological isolation
4. None of the above.

Answer: 1. Ecological isolation

Question 67. A post-mating isolating mechanism in which the development of a hybrid zygote is often irregular and may end at any stage between fertilization and adulthood, is known as:

1. Hybrid inferiority
2. Hybrid sterility
3. Hybrid inviability
4. Gametic mortality.

Answer: 3. Hybrid inviability

Question 68. ______ isolation refers to the barriers to mating among individuals of different species in their courtship behaviour:

1. Ethological
2. Mechanical
3. Ecological
4. Seasonal.

Answer: 1. Ethological

Question 69. Mutation, natural selection, genetic drift and emigration are considered to be essential factors of evolution. The statement that best explains genetic drift is:

1. The shifting of a species or population from one place to another
2. The fixation of adaptive traits in the population
3. The accidental fluctuations in the frequency of an allele in a population.

Answer: 3. The accidental fluctuations in the frequency of an allele in a population.

Question 70. Neo-Darwinism does not appreciate the role in the evolution of:

1. Natural selection
2. Adaptation
3. Mutations
4. Germplasm.

Answer: 3. Mutations

Question 71. Which of the following statements is false?

1. Selection is most effective for recessive mutations
2. Forces of selection pressure and mutation pressure are antagonistic to each other
3. Directional selection tends to reduce variance
4. Natural selection is a creative force in evolution.

Answer: 1. Selection is most effective for recessive mutations

Question 72. The barriers which check the free exchange of genes between populations (subspecies) are called:

1. Gene barriers
2. Isolating barriers
3. Exchange barriers
4. All the above.

Answer: 2. Isolating barriers

Question 73. Galapagos islands in the Pacific Ocean on the west coast of South America is a chain of:

1. 41 islands
2. 14 islands
3. 4 islands
4. 141 islands.

Answer: 2. 14 islands

Question 74. In addition to the other books, Darwin also wrote:

1. Origin of man
2. Ascent of man
3. Descent of man
4. Evolution of man.

Answer: 3. Descent of man

PSEB Class 12 Biology Evolution MCQs with Answers

Question 75. One of the following plants is tolerant to selenium:

1. Astragalus
2. Agrostis tenuis
3. Impatiens balsatuia
4. Both (1) and (2)

Answer: 4. Both (1) and (2)

Question 76. When a hybrid produces sterile or infertile offspring, it is known as:

1. Hybrid sterility
2. Hybrid breakdown
3. Hybrid inviability
4. Gametic isolation.

Answer: 3. Hybrid inviability

Question 77. The distribution of land snails in Hawaiian islands affords an example of:

1. Geographical isolation
2. Seasonal isolation
3. Climatic isolation
4. Habitat isolation.

Answer: 1. Geographical isolation

Question 78. Which of the following is a post-mating isolating mechanism?

1. Physiological isolation
2. Hybrid sterility
3. Mechanical isolation
4. Ethological isolation.

Answer: 2. Hybrid sterility

Question 79. Point out the pre-mating isolating mechanism from the following:

1. Gametic mortality
2. Hybrid inviability
3. Hybrid inferiority
4. Isolation due to distance.

Answer: 4. Isolation due to distance.

Question 80. Penguins occur at the south pole while the north pole has polar bears and not penguins. Why?

1. The south pole is colder than the North Pole
2. Bears are the evolved form of penguins
3. These areas are separated geographically from each other
4. It is a question of special creation.

Answer: 3. These areas are separated geographically from each other

Question 81. Chinese women used to keep their feet enclosed in iron shoes for many years so that their feet remained small in size. Is this character passed on to the next generation?

1. Yes, as the change is somatogenic
2. Yes, as the change is blastogenic
3. No, it is an acquired character
4. It varies from individual to individual.

Answer: 3. No, it is an acquired character

Question 82. A penguin is a bird that lost the use of its wings by not flying. Such a statement would express the views of:

1. Darwin
2. Wallace
3. Lamarck
4. Huxley.

Answer: 3. Lamarck

Question 83. An Indian and a Japanese though differing in physical features resemble each other precisely at the level of:

1. Karyotype
2. Gene pool
3. Nutritional requirements
4. Believing in marriage to get offspring.

Answer: 1. Karyotype

Question 84. The mule is a hybrid of:

1. Female horse and male ass
2. Male ass and female zebra
3. Male ass and male zebra
4. Female and male zebra

Answer: 1. Female horse and male ass

PSEB Class 12 Biology Evolution MCQs with Answers

Question 85. The hybrid zygotes produced in fishes fail to cleave and develop properly. It is due to:

1. Hybrid non-viability
2. Hybrid sterility
3. Failure to attain sexual maturity
4. F₂ generation sterility.

Answer: 1. Hybrid non-viability

Question 86. Darwinism is based on:

1. Struggle for existence
2. Survival of the fittest and natural selection
3. Origin of new species
4. All of the above.

Answer: 4. All of the above.

Question 87. Who wrote the essay on Population?

1. Lamarck
2. Malthus
3. Darwin
4. Morgan.

Answer: 2. Malthus

Question 88. Who proposed the concept of intraspecific and interspecific struggle?

1. De Vries
2. Malthus
3. Darwin
4. None of the above.

Answer: 3. Darwin

Question 1. Which of die following Mendel’s law has not been proven to be true in all the cases?

1. Law of segregation
2. Law of independent assortment
3. Law of dominance
4. None of these.

Answer: 3. Law of dominance

Question 2. When the tall red plant is crossed with a dwarf white plant, all the plants of F₁ generation are found to be tall red. Which of the following ratios will be available when a test cross is made?

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

Answer: 1.1: 1 : 1: 1

Question 3. The three important laws of heredity proposed by Mendel relate to :

1. Gene linkage, character segregation and independent assortment
2. Gene linkage, dominance and segregation
3. Segregation, independent assortment and dominant recessiveness
4. Segregation, independent assortment and gene linkage.

Answer: 3. Segregation, independent assortment and dominant recessiveness

Read and Learn More 12th Class Biology MCQs

Question 4. Which one of the following statements is true of Mendel’s theory but not of Darwin’s theory of natural selection?

1. The original theory was modified later on
2. The theory immediately and strongly influenced other areas of human knowledge
3. Clearly defined laws were proposed during the early stages of the theory.
4. The theory was based mostly on pathological studies.

Answer: 3. Clearly defined laws were proposed during the early stages of the theory.

PSEB Class 12 Biology Elements Of Heredity And Variations MCQs

Question 5. Lethal genes are those which cause :

1. Die death of the homozygous infant being formed
2. Night blindness
3. Colour blindness
4. Linkage and crossing over.

Answer: 1. Die death of the homozygous infant being formed

Question 6. There is a resemblance between parents and offspring but not the exact likeness. This is because of:

1. Variations produced by crossing over at the time of gamete formation
2. Variations produced by chance distribution of chromosomes to the two  poles of meiosis I
3. Both the above  and  points
4. None of the above points.

Answer: 3. Both the above  and the points

Question 7. When one gene pair hides the effect of another pair, this phenomenon is referred to as :

1. Mutation
2. Epistasis
3. Dominance
4. None of the above.

Answer: 2. Epistasis

Question 8. In a dihybrid cross, Fj individuals arc self-crossed, phenotypic ratio  comes to be 15: 1. It is due to :

1. Duplicate genes
2. Supplementary genes
3. Dominant epistasis
4. Recessive epistasis

Answer: 1. Duplicate genes

Question 9. An Execution of Mendel’s law is:

1. Independent assortment
2. Dominance
3. Purity of gametes
4. Linkage.

Answer: 4. Linkage.

Question 10. Complementary genes show a ratio of :

1. 1: 1
2. 3 :1
3. 9: 7
4. 9:3:3: 1.

Answer: 3. 9: 7

Elements Of Heredity And Variations Multiple Choice Questions PSEB Class 12

Question 11. If 3ⁿ is the number of genotypes where ‘n’ is the number of different chromosome pairs with each carrying one heterozygous allele, what would be the different genotypes produced by garden pea plant?

1. 310
2. 312
3. 314
4. 37

Answer: 4. 37

Question 12. If a dihybrid for the character is crossed to a homozygous recessive  individual for the same character, the phenotypic ratio of the progeny  would be :

1. 1:1:1:1
2. 1:2:1
3. 3: 1
4. 13:3.

Answer: 1. 1:1:1:1

Question 13.Genes which have similar phenotypic effects when present separately but interact to produce a new phenotype when present together are known as :

1. Supplementary genes
2. Complementary genes
3. Epistatic genes
4. Inhibitory genes.

Answer: 2. Complementary genes

Question 14. In a green pod of pea, the seed-coat colour changed from grey to white. This is an example of:

1. Chlorosis
2. Spontaneous mutation
3. Pleiotropic mutation
4. Transformation.

Answer: 2. Spontaneous mutation

Question 15. If the genotype of an individual is AA Bb CC, it is a :

1. Trihybrid
2. Monohybrid
3. Dihybrid
4. None of the above.

Answer: 2. Monohybrid

Question 16. An individual heterozygous for two alleles (Aa Bb) produces two million sperms; how many of the sperms will have both the recessive alleles :

1. 1 million
2. 2 million
3. 0.5 million
4. 0.25 million.

Answer: 3. 0.5 million

Question 17. If the frequency of a dominant phenotype in a stable population is 75%, the frequency of a dominant allele in the population would be: 

1. 37.5%
2. 75%
3. 9.4%
4. 50%.

Answer: 4. 50%.

Elements Of Heredity And Variations Multiple Choice Questions PSEB Class 12

Question 18. If two hybrids for the same quantitative character are crossed the phenotypic ratio of progeny would be ;

1. 1:4 : 6: 4: 1
2. 15: 1
3. 12:3:1
4. 9: 7.

Answer: 1. 1:4 : 6: 4: 1

Question 19.In a cross between a pure tall pea plant with a green pod and a pure short plant with a yellow pod, how many short plants you would expect in F₂, generation?

1. 4
2. 9
3. 3
4. 1.

Answer: 1. 4

Question 20. From a single car of com, a far nu’r planted 200 kernels which produced NO tall and 10 short plants. The genotypes of these offspring are most likely :

1. TT and Tt only
2. IT, Tt and tl
3. tt and tt only
4. TT and tt only.

Answer: 2. IT, Tt and tl

Question 21. An individual with genotype Aa Bb Co will produce ; 

1. Four types of gametes
2. All gametes of the same type
3. Eight different types of gametes
4. Four gametes of one type and the remaining gametes Of the same type.

Answer: 3. Eight different types of gametes

Question 22. Mendel was successful in formulating the laws of inheritance whereas his predecessors were not because :

1. Of the right choice of material
2. They studied one clear-cut character at a time with no intermediates
3. The characters studied by him were present on separate chromosomes and  showed no linkage
4. All the above.

Answer: 4. All the above.

Question 23. A test cross : 

1. Is commonly used to investigate the genotype of the diploid individual
2. Involves mating one genotype to another homozygous for all dominant  genes under consideration
3. Involves mating one genotype to another homozygous for recessive  alleles of all genes under consideration
4. Both 1 and 3

Answer: 4. Both 1 and 3

Class 12 Biology Chapter Elements Of Heredity And Variations MCQs

Question 24. Mendel formulated the laws of heredity considering seven pairs of characters in the pea plant. If he had studied an eighth pair, the law  which would have been altered is:

1. Law of segregation
2. Law of independent assortment
3. Law of dominance
4. Law of unit character.

Answer: 2. Law of independent assortment

Question 25. In the F₂ generation, genotypic and phenotypic ratios are identical in M case of:

1. Mendelian nanohybrids
2. Mendelian dihybrids
3. Incomplete dominance
4. None of the above.

Answer: 3. Incomplete dominance

Question 26. The segregation of paired hereditary factors that Mendel postulated occurs during :

1. Prophase of first meiotic division
2. Anaphase of first meiotic division
3. During interphase between two meiotic divisions
4. Metaphase of the second meiotic division.

Answer: 2. Anaphase of first meiotic division

Question 27. The independent assortment of two pairs of genes located on  non-homologous chromosomes occur as a result of the random orientation of chromosomes during :

1. Metaphase of the first meiotic division
2. Telophase of the first meiotic division
3. The brief interphase between the two meiotic- divisions
4. Prophase of the second meiotic division.

Answer: 1. Metaphase of the first meiotic division

Question 28. Appearance of hidden character in some progeny of F₂ generation proclaims:

1. Law of Independent assortment
2. Law of Dominance
3. Law of Fiuily ol gametes
4. None of the above,

Answer: 3. Law of Fiuily ol gametes

Question 29. Mendelian recombinations are due to :

1. Linkage
2. Modifications
3. Independent assortment of characters
4. Mutation.

Answer: 3. Independent assortment of characters

Question 30. Mendel law of segregation is based upon the F₂ ratio of:

1. 1: 2
2. 1:2:1
3. 9:3:1
4. 3: 1

Answer: 4. 3: 1

Class 12 Biology Chapter Elements Of Heredity And Variations MCQs

Question 31. Which one of the following characters in man is controlled by a  recessive gene?

1. Woolly hair
2. Brachydactyly
3. Colour blindness
4. Night blindness.

Answer: 3. Colour blindness

Question 32. The constriction on chromosomes where the spindle fibres attach during cell division arc :

1. Chromatids
2. Chromonemata
3. Centromere
4. Chromomere.

Answer: 3. Centromere

Question 32. As a result of linkage and crossing over:

1. Chromatids become chromosomes
2. Nuclear divisions come to a close
3. Chromosomes become half in number
4. Exchange of chromosomal material occurs.

Answer: 4. Exchange of chromosomal material occurs.

Question 33. Gene P and Q are necessary for normal hearing. A deaf man marries a deaf woman and all their children have normal hearing. The genotypes of the parents are :

1. PPqq x PPqq
2. Ppqq x ppQq
3. PPqq x ppQQ
4. ppQQ x ppQq.

Answer: 3. PPqq x ppQQ

Question 34.A plant with Aa Bb composition, on self-pollination results in which of the following genetic frequencies among the dominant phenotypes?

AABB : AABb : Aa BB : AaBb

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

Answer: 1. 1 : 2 : 2 : 4

Question 35. “Like begets like” is an important and universal phenomenon of life, is due to :

1. Euthenics
2. Inheritance
3. Dominance
4. Eugenics.

Answer: 1. Euthenics

Question 36. The father of genetics G.J. Mendel is famous for propounding :

1. Theory of acquired character
2. Cell theory
3. Laws of inheritance
4. Origin of species.

Answer: 3. Laws of inheritance

PSEB Class 12 Biology Genetics MCQs with Answers

Question 37. The frequency of a mutant gene in a population is expected to increase if the gene is:

1. Dominant
2. Recessive
3. Favourably selected
4. Sex-linked.

Answer: 1. Dominant

Question 38. Genetic information is carried out by a long chain of molecules made up of:

1. Enzymes
2. Nucleotides
3. Amino acids
4. Chromosomes.

Answer: 2. Nucleotides

Question 39. Mendel studied seven contrasting characters for his breeding experiments: which of the following characters he did not study?

1. Plant height
2. Pod colour
3. Pod shape
4. Leaf shape.

Answer: 4. Leaf shape.

Question 40. A normal plant suddenly started producing Parthenon genetically. the number of chromosomes of the second generation compared to the parent plant will be :

1. Double
2. One half
3. One fourth
4. Same.

Answer: 2. One half

Question 41. Why were pea plants more suitable than dogs for Mendel’s experiments?

1. There were no pedigree records of dogs
2. Pea plants can be self-pollinated
3. Dogs have many genetic traits
4. All pea plants are diploid.

Answer: 2. Pea plants can be self-pollinated

Question 42. Suppose pea plant’s tallness is dominant over dwarfness, to determine whether a tall pea plant is homozygous or heterozygous, it should be crossed with the:

1. A homozygous tall pea plant
2. A homozygous dwarf pea plant
3. Any tall pea plant
4. Any pea plant.

Answer: 2. A homozygous dwarf pea plant

Question 43. The term gene was given by :

1. Bateson
2. Johannsen
3. Punnet
4. Darlington.

Answer: 2. Johannsen

PSEB Class 12 Biology Genetics MCQs with Answers

Question 44. The term back cross refers to :

1. A cross between F| hybrid and either of the parents
2. A cross between one Fj-and another Fj hybrid
3. A cross between Fj hybrid and Fj individuals
4. None of these.

Answer: 1. A cross between F| hybrid and either of the parents

Question 45. A cross between unlike organisms is called as :

1. Hybridisation
2. Heterosis
3. Backcross
4. Test cross.

Answer: 1. Hybridisation

Question 46. If Mendel had, by chance, chosen to study two traits determined by linked genes, he would have not been able to derive the :

1. Law of dominance
2. Law of independent assortment
3. Law of unit character
4. Law of segregation.

Answer: 2. Law of independent assortment

Question 47. The character which predominates and is seen in F, generation is said to be :

1. Common
2. Dominant
3. Special
4. Recessive.

Answer: 2. Dominant

Question 48. The ratio of recessive epistasis :

1. 9:3:4
2. 13:3
3. 12:3: I
4. 15: 1.

Answer: 2.13:3

PSEB Class 12 Biology Genetics MCQs with Answers

Question 49. A pure tall pea plant was reared in soil poor in nutrition and reached the size of the pure dwarf pea plant. If this pea plant is selfed  then the phenotype in the F| generation is most likely to be :

1. All tall
2. 50% tall and 50% dwarf
3. All dwarf
4. Data are insufficient.

Answer: 1. All tall

Question 50. In a monohybrid cross, 2 heterozygous individuals were crossed,  phenotype ratio comes to be 2: 1. It is due to :

1. Dominant lethal genes in homozygous condition
2. Dominant lethal genes in heterozygous individuals
3. Dominant epistasis
4. None of the above.

Answer: 1. Dominant lethal genes in homozygous condition

Enzymes Multiple Choice Questions

Question 1. The enzyme which joins with the non-proteinic part to form a functional enzyme is:

1. Holoenzyme
2. Prosthetic group
3. Apoenzyme
4. Coenzyme.

Answer: 3. Apoenzyme

Question 2. Enzymes that help in electron transfer are :

1. Cytochrome
2. Isomerase
3. Proteinase
4. All of the above.

Answer: 1. Cytochrome

Question 3. Induced-fit theory of enzyme action was given by:

1. Koshland
2. Sumner
3. Fischer
4. Hershey and Chase.

Answer: 1. Koshland

Read and Learn More 12th Class Biology MCQs

Question 4. The most abundant enzyme among living organisms is:

1. Catalase
2. Rubisco
3. Nitrogenase
4. Invertase.

Answer: 2. Rubisco

PSEB 12th Class Biology Enzymes MCQs

Question 5. Enzymes speed up the rate of reaction by :

1. Combining with product
2. Forming reactant-product complex
3. Changing the equilibrium of the reaction
4. Lowering activation energy.

Answer: 4. Lowering activation energy.

Question 6. The enzyme which fixes CO₂ in C₄ plants, is :

1. Hydrogenase
2. Pepcarboxyease
3. Reductase
4. Rubp carboxylase.

Answer: 2. Pepcarboxyease

Question 7. Endoenzymes generally act at:

1. Neutral ph
2. Alkaline ph
3. Any ph
4. Acidic ph.

Answer: 1. Neutral ph

Question 8. The nomenclature of the enzyme consists of :

1. First name of the product and then reaction name
2. Only product name
3. Only reaction name
4. First reaction, then product name.

Answer: 1. First name of the product and then reaction name

Question 9. Holoenzyme is :

1. Protein moiety of enzyme
2. Non-protein moiety of enzyme
3. Complete enzyme
4. Inactive enzyme.

Answer: 3. Complete enzyme

Enzymes Multiple Choice Questions PSEB Class 12

Question 10. The energy released from enzyme-substrate interaction is known as:

1. Activation energy
2. Binding energy
3. Constant energy
4. Variable energy.

Answer: 2. Binding energy

Question 11. The enzyme involved in the hydrolysis of starch to maltose is called:

1. Sucrase
2. Amylase
3. Lactase
4. Maltase.

Answer: 2. Amylase

Question 12. The hydrolytic enzymes acting at low pH are termed:

1. Alpha amylase
2. Hydrolases
3. Proteases
4. Pyrimnidases

Answer: 1. Alpha-amylase

Question 13. The glycogen in a dead or killed animal is disintegrated by the enzymatic action to:

1. Glucose
2. Fructose
3. Lactose
4. None of the above.

Answer: 4. None of the above.

Question 15. Enzymes, vitamins, and hormones can be classified into a single category of biological chemicals because all of these:

1. Enhance oxidative metabolism
2. Ale conjugated proteins
3. Are exclusively synthesized in the body of a living
   an organism as at present.
4. Help in regulating metabolism

Answer: 4. Help in regulating metabolism

Question 16. Which of the following statements regarding enzyme inhibition is correct?

1. Non-competitive inhibition of an enzyme can be overcome by adding a large amount of substrate.
2. Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein.
3. Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the
4. Non-competitive inhibitors often bind to the enzyme irreversibly.

Answer: 3. Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the

Class 12 Biology Chapter Enzymes MCQs

Question 17. The catalytic efficiency of two different enzymes can be compared by the :

1. The km value
2. The pH optimum value
3. Formation of the product
4. The molecular size of the enzyme.

Answer: 1. The km value

Question 18. Telomerase is an enzyme that is a :

1. Repetitive dna
2. Rna
3. Simple protein
4. Ribonucleic protein

Answer: 4. Ribonucleoprotein

Question 19. The figure given below shows three velocity-substrate concentration curves for an enzyme reaction. What do the curves a, b, and c depict respectively?

Image-

1. A-normal enzyme reaction, b-competitive c-non-competitive inhibition
2. A-enzyme with an allosteric modulator added, b-normal enzyme activity, c-competitive inhibition
3. A-enzyme with an allosteric stimulator, b-competitive inhibition added c-normal enzyme reaction
4. A-normal enzyme reaction. B-non-competitive inhibitor added
   c-allosteric inhibitor added.

Answer: 1. A-normal enzyme reaction, b-competitive c-non-competitive inhibition.

Question 21. In which one of the following sets of three items each belong to the category tensioned against them?

1. Lysine, glycine, thiamine…..amino acids
2. Myosin, oxytocin, and gastrin……hormones
3. Rennin, helicase, and hyaluronidase….enzymes
4. Optic nerve, oculomotor, vagus…..sensory nerves.

Answer: 3. Rennin, helicase, and hyaluronidase….enzymes

Question 21. Assertion: a coenzyme or metal ion that is very tightly bound to an enzyme protein is called a prosthetic.

Reasons: a complete, catalytically active enzyme together with its bound prosthetic group is called an apoenzyme.

1. Both and (r) are true and (r) is the correct explanation of the
2. Both and (r) are true but the (r) is not the correct explanation of the
3. Is a true statement but (r) is false
4. Both and (r) are false.

Answer: 3. Is a true statement but (r) is false

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

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

Answer: 1. A fixation of nitrogen in legumes

Question 23. Which of the following cell organelles is rich in catabolic enzymes?

1. Ribosomes
2. Chloroplast
3. Mitochondria
4. Golgi complex.

Answer: 3. Mitochondria

Question 24. Cytochrome oxidase is a.an :

1. Coenzyme
2. Proenzyme
3. Exoenzyme
4. Endoenzyme

Answer: 4. Endoenzyme

Question 25. Enzymes found attached to the inner membrane of mitochondria instead of the matrix are :

1. Succinic acid dehydrogenase
2. Cytochrome oxidase
3. Malic acid dehydrogenase
4. Both 1 and 2.

Answer: 4. Both 1 and 2.

PSEB 12th Class Biology Enzymes Questions with Answers

Question 26. A competitive inhibitor of succinic dehydrogenase is :

1. Malate
2. Maionate
3. Oxaloacetate
4. A-ketoglutarate

Answer: 2. Maionate

Question 27. An example of feedback inhibition is :

1. Cyanide action on cytochrome
2. Sulpha drug on folic acid synthesizer bacteria
3. Allosteric inhibition of hexokinase by glucose 6- phosphate
4. Reaction between succinic dehydrogenase and succinate.
5. The inhibition of succinic dehydrogenase by malonate.

Answer: 3. Allosteric inhibition of hexokinase by glucose 6- phosphate

Question 28. The essential chemical components of many coenzymes

1. Nucleic acids
2. Carbohydrates
3. Vitamins
4. Proteins

Answer: 3. Vitamins

Question 29. The transition state structure of the substrate formed during an enzymatic reaction is :

1. Permanent but unstable
2. Transient an unstable
3. Permanent and stable
4. Transient but stable

Answer: 2. Transient an unstable

Question 1. What evidence suggests that chimpanzees are more closely related to humans than other hominid species?

1. DNA from sex chromosomes only
2. Chromosome morphology only
3. Fossil remains
4. DNA of both autosomes and sex chromosomes.

Answer: 4. DNA of both autosomes and sex chromosomes.

Question 2. The cranial cavity of Australopithecus was:

1. 650-700 cm³
2. 350-450 cm³
3. 1050-1150 cm³
4. 1400-1450 cm³

Answer: 2. 350-450 cm³

Question 3. Tuang baby is:

1. Dryopithecus
2. Australopithecus
3. Peking man
4. Piltdown man.

Answer: 2. Australopithecus

Read and Learn More 12th Class Biology MCQs

Question 4. Which one of the following apes is found in India:

1. Gorilla
2. Gibbon
3. Chimpanzee
4. Orangutan.

Answer: 1. Gorilla

PSEB 12th Class Biology Evolution Of Man MCQs

Question 5. Most primary hominids that appeared were:

1. Pleistocene
2. Early Miocene
3. Late Miocene and early Pliocene
4. Late Pliocene.

Answer: 3. Late Miocene and early Pliocene

Question 6. There are two opposing views about the origin of modern man. According to one view Homo erectus in Asia were the ancestors of modem man. A study of variations of DNA however suggested the African origin of modern man. What kind of observation of DNA variation could suggest this?

1. Greater variation in Africa than in Asia
2. Variation only in Asia and no variation in Africa
3. Greater variation in Asia than in Africa
4. Similar variations in Africa and Asia.

Answer: 1. Greater variation in Africa than in Asia

Question 7. The last common ancestor between the African apes and hominids lived during the epoch:

1. Oligocene
2. Pliocene
3. Millocene
4. Pleistocene.

Answer: 2. Pliocene

Question 8. What was the most significant trend in the evolution of modem (Homo sapiens) from his ancestors?

1. Binocular vision
2. Increasing cranial capacity
3. Upright posture
4. Shortening of jaws.

Answer: 2. Increasing cranial capacity

Question 9. The cranial capacity of Neanderthal man was about:

1. 1450 cc
2. 900 cc
3. 650 cc
4. 1100 cc.

Answer: 1. 1450 cc

Question 10. What is the correct sequence of human evolution:

1. Ramapithecus → Australopithecus → Homo erectus → Neanderthal → Homo sapiens sapiens
2. Ramapithecus → Homo habilis → Homo sapiens sapiens → Homo erectus
3. Australopithecus → Ramapithecus → Homo habilis → Homo sapiens sapiens
4. Homo habilis → Australopithecus → Homo erectus → Homo sapiens sapiens.

Answer: 1. Ramapithecus → Australopithecus → Homo erectus → Neanderthal → Homo sapiens sapiens

Question 11. Among the human ancestors the brain size was more than 1000 cc in:

1. Homo erectus
2. Ramapithecus
3. Homo habilis
4. Homo neanderthalensis.

Answer: 4. Homo neanderthalensis.

Evolution Of Man Multiple Choice Questions PSEB Class 12

Question 12. What was the most significant trend in the evolution of modem man (Homo sapiens) from his ancestors?

1. Upright posture
2. Shortening of jaws
3. Binocular vision
4. Increasing brain capacity.

Answer: 4. Increasing brain capacity.

Question 13. Which of the following is used as an atmospheric pollution indicator?

1. Lepidoptera
2. Lichens
3. Lycopersicon
4. Lycopodium.

Answer: 2. Lichens

Question 14. The theory of spontaneous generation states that:

1. Life arose from living forms only
2. Life can arise from both living and non-living
3. Life can arise from non-living things only
4. Life arises spontaneously, neither from living nor from the non-living.

Answer: 3. Life can arise from non-living things only

Question 15. Animal husbandry and plant breeding programs are examples of:

1. Reverse evolution
2. Artificial selection
3. Mutation
4. Natural selection.

Answer: 2. Artificial selection

Question 16. Palaeontological evidence for evolution refers to the.

1. Development of embryo
2. Homologous organs
3. Fossils
4. Analogous organs.

Answer: 3. Fossils

Question 17. The bones of forelimbs of whales, bats, cheetahs, and man are similar in structure, because:

1. One organism has given rise to another
2. They share a common ancestor
3. They perform the same function
4. They have biochemical similarities.

Answer: 2. They share a common ancestor

Evolution Of Man Multiple Choice Questions PSEB Class 12

Question 18. Analogous organs arise due to:

1. Divergent evolution
2. Artificial selection
3. Genetic drift
4. Convergent evolution.

Answer: 4. Convergent evolution.

Question 19. (p+q)² = p² + 2pq + q² = 1 represents an equation used in:

1. Population genetics
2. Mendelian genetics
3. Biometrics
4. Molecular genetics.

Answer: 3. Biometrics

Question 20. Appearance of antibiotic-resistant bacteria is an example of:

1. Adaptive radiation
2. Transduction
3. Pre-existing variation in the population
4. Divergent evolution.

Answer: 3. Pre-existing variation in the population

Question 21. Evolution of life shows that life forms had a trend of moving from:

1. Land to water
2. Dryland to wetland
3. Fresh water to seawater
4. Water to land.

Answer: 4. Water to land

Question 22. Viviparity is considered to be more evolved because

1. The young ones are left on their own
2. The young ones are protected by a thick shell
3. The young ones are protected inside the mother’s body and are looked after they are bom leading to more chances of survival
4. The embryo takes a long time to develop.

Answer: 3. The young ones are protected inside the mother’s body and are looked after they are bom leading to more chances of survival

Question 23. Fossils are generally found in:

1. Sedimentary rocks
2. Igneous rocks
3. Metamorphic rocks
4. Any type of rock.

Answer: 1. Sedimentary rocks

Question 24. For the MN-blood group system, the frequencies of M and N alleles arc 0.7 and 0.3, respectively. The expected frequency of MN-blood group-bearing organisms is likely to be.

1. 42%
2. 49%
3. 9%
4. 58%.

Answer: 1. 42%

Question 25. Which type of selection is industrial melanism observed in moths? Bistort Bulgaria:

1. Stabilizing
2. Directional
3. Disruptive
4. Artificial.

Answer: 2. Directional

Question 26. The most accepted line of descent in human evolution is:

1. Australopithecus → Ramapithecus → Home sapiens → homo habilis
2. Home ercctus → Homo habilis → Homo sapiens
3. Ramapithecus → Homo habilis → Homo erectus → Homo sapiens
4. Australopithecus → Ramapithecus → Homo erectus → Homo habilis → Homo sapiens.

Answer: 3. Ramapithecus → Homo habilis → Homo erectus → Homo sapiens

Question 27. Which of the following is an example of connecting link species?

1. Lobe fish
2. Dodo bird
3. Seaweed
4. Tyrannosaurus rex.

Answer: 1. Lobe fish

Question 28. Match the scientists listed under column ‘A’ with ideas listed in column ‘B’.

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

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

Question 29. In 1953 S.L. Miller created primitive earth conditions in the laboratory and gave experimental evidence for the origin of the first form of life from pre-existing non-living organic molecules. The primitive earth conditions created include:

1. Low temperature, volcanic storms, an atmosphere rich in oxygen
2. Low temperature, volcanic storms, reduced atmosphere
3. High temperature, volcanic storms, non-reducing atmosphere
4. High temperature, volcanic storms, reducing atmosphere containing CH₄, NH₃, etc.

Answer: 4. High temperature, volcanic storms, reducing atmosphere containing CH₄, NH₃, etc.

Class 12 Biology Chapter Evolution Of Man MCQs

Question 30. Variations during mutations of meiotic recombinations are:

1. Random and directionless
2. Random and directional
3. Random and small
4. Random small and directional.

Answer: 1. Random and directionless

Question 31. The essence of Darwinian theory about evolution is:

1. The rate of appearance of new forms linked to the life cycle
2. Natural selection
3. Artificial selection
4. Both (1) and (2).

Answer: 4. Both (1) and (2).

Question 32. Darwin’s theory of natural selection was influenced by the work of:

1. Herbert Spencer
2. Thomas Malthus
3. Lamarck
4. I. A. Oparin.

Answer: 2. Thomas Malthus

Question 33. Natural selection is based on certain observations which are factual. They are:

1. Limited natural resources
2. Populations are stable
3. Members of the population vary in characteristics that are inherited.
4. All the above.

Answer: 4. All the above.

Question 34. Key concepts of Darwinian theory are:

1. Branching descent
2. Natural selection
3. Inheritance of all traits
4. Both (1) and (2).

Answer: 4. Both (1) and (2).

Question 35. The process of evolution of different species in a given geographical area starting from a point and spreading to other areas is called:

1. Adaptive radiation
2. Convergent evolution
3. Parallel evolution
4. Co-evolution.

Answer: 1. Adaptive radiation

Question 36. Huge clusters of galaxies comprise the universe. This universe is how many years old?

1. 200 million
2. 20 million
3. 300 billion
4. 20 billion.

Answer: 4. 20 billion.

Question 37. Big Bang theory explains the origin of the universe. Did life appear on earth about how many years ago?

1. 500 million after the formation of the earth
2. 4 billion years ago
3. 4.5 billion years ago
4. Both (1) and (2) correct

Answer: 4. Both (1) and (2) correct

Class 12 Biology Chapter Evolution Of Man MCQs

Question 38. Analogous structures are a result of:

1. Convergent evolution
2. Divergent evolution
3. Microevolution
4. Coevolution.

Answer: 1. Convergent evolution

Question 39. Hardy-Weinberg equilibrium is affected by

1. Gene flow and genetic drift
2. Mutation and genetic recombination
3. Natural selection
4. All the above.

Answer: 4. All the above.

Question 40. Dinosaurs became extinct during which period:

1. Jurassic
2. Cretaceous
3. Tertiary
4. Triassic.

Answer: 3. Tertiary

Question 41. The Neanderthal man with a brain size of 1400 cc lived near East and Central Asia between:

1. 100,000 – 40,000 years ago
2. 75,000 – 10,000 years ago
3. 18,000 years ago
4. 10,000 years ago.

Answer: 1. 100,000 – 40,000 years ago

Question 42. The biggest dinosaurs about 20 ft in height were:

1. Ichthyosaurs
2. Tyratmosams
3. Stegosaur
4. Triceratops.

Answer: 2. Tyratmosams

Question 43. Which of the following is correct?

1. Jean-Baptiste Lamarck (1744-1829) a French biologist was an advocate of evolution during the pre-Darwin era.
2. Lamarck could recognize several lines of descent or lineage of modern species
3. Lamarck could arrange the fossils in chronological series of order from older to younger form
4. All are correct.

Answer: 4. All are correct.

Question 44. A new mutation spreads from one population to another by means of:

1. Removed bottlenecks
2. Emigrants and immigrants
3. Mutation pressure
4. Cross overs.

Answer: 3. Mutation pressure

Question 45. Genetic drift occurs when a few individuals of a species colonize in land. The particular phenomenon is:

1. Bottleneck effect
2. The founder effect
3. Associative mating
4. Random mating.

Answer: 2. The founder effect

Question 46. A plant population that reproduces by self-pollination is an extreme example of:

1. The bottleneck effect
2. The founder effect
3. Rapid gene flow
4. Assortative mating.

Answer: 4. Assortative mating.

Question 47. Lumpers tend to:

1. Separate the same population into different species or group
2. Combine population into single species or group
3. Recognize the basic species
4. All the above.

Answer: 2. Combine the population into single species or group

PSEB 12th Class Biology Human Evolution MCQs with Answers

Question 48. Reproductive isolation in sympatric speciation develops without a:

1. Geographical barrier
2. Barrier to mating
3. Change in chromosome number
4. The barrier to gene flow.

Answer: 1. Geographical barrier

Question 49. Which of the following is the most rapid method of speciation?

1. Polyploidy
2. Sympatric
3. Allopatric
4. Isolation.

Answer: 1. Polyploidy

Question 50. Common bread wheat is thought to have arisen through:

1. Parapatric speciation
2. Allopatric speciation
3. Polyploidy and cross-fertilisation
4. Ecological separation.

Answer: 4. Ecological separation.

Question 51. Which of the following originated during the Miocene epoch in Africa and Asia?

1. Ramapithcus
2. Dryopithecus
3. Sivapithcus
4. Parapithecus.

Answer: 2. Dryopithecus

Question 52. Homo habilis, a tool maker having a cranial capacity of? 735 cc and bipedal gait existed during which epoch?

1. Pleistocene
2. Miocene
3. Pliocene
4. Oligocene.

Answer: 1. Pleitostocene

Question 53. The most recent products of animal evolution are:

1. Birds
2. Mammal
3. Snakes and crocodiles
4. Lizards and turtles.

Answer: 2. Mammal

Question 54. Apes have:

1. Arms shorter than legs
2. Arms longer than legs
3. 900-1500 Cc cranial capacity
4. Strictly herbivorous feeding habit.

Answer: 2. Arms longer than legs

PSEB 12th Class Biology Human Evolution MCQs with Answers

Question 55. Cromagnon man had:

1. Highest cranial capacity
2. Lived in caves and was a hunter
3. The ability to make tools and weapons
4. All the above.

Answer: 4. All the above.

Question 56. Which fossil man had a cranial capacity almost equal to modern man?

1. Peking man
2. Java ape man
3. Neanderthal man
4. Sivapithecus.

Answer: 3. Neanderthal man

Question 57. A cranial capacity of about 1200 cc belongs to

1. Java man
2. Peking man
3. Cromagnon man
4. Both (1) and (2).

Answer: 2. Peking man

Question 58. Who discovered Java man?

1. Leaky
2. Levis
3. Dubois
4. Oparin.

Answer: 3. Dubois

Question 59. Handyman is:

1. Cromagnon man
2. Neanderthal man
3. Homo habilis
4. None of the above.

Answer: 3. Homo habilis

Question 60. The evolution of man came after Dry epithets

1. Ramapithecus
2. Proconsul
3. Shivapilhecus
4. Australopithecus.

Answer: 1. Ramapithecus

Question 61. Which of the following is closest to man?

1. Neanderthal
2. Cromagnon
3. Homo credits
4. Homo habilis.

Answer: 2. Cromagnon

Question 62. Which of the following is not a feature of apes?

1. Absence of tail
2. Arboreal habitat
3. Narrow pelvis
4. Occipital condyles lateral in position.

Answer: 4. Occipital condyles lateral in position.

PSEB 12th Class Biology Human Evolution MCQs with Answers

Question 63. Which of the following is not a feature of present-day man?

1. More hair
2. Distinct chin
3. Bipedal gait
4. Steep and high brow.

Answer: 1. More hair

Question 64. Which of the following is not a feature of Australopithecus?

1. Simian gap present
2. The forward position of the foramen magnum
3. Basin-like pelvic girdle
4. Erect posture with four feet height.

Answer: 1. Simian gap present

Question 65. Homo areas show:

1. Upright bipedal locomotion
2. 700-800 cranial capacity
3. Forehead present
4. Rounded skull.

Answer: 1. Upright bipedal locomotion

Question 66. Six races i.e. Negroid, Casusacoid. Mongaloid, Australcoid, Polynesian, and Bushman were recognized by

1. May (1950)
2. Leaky
3. Mansell (1962)
4. Colbert (1995).

Answer: 3. Manell (1962)

Question 67. Parapithecus was discovered by:

1. Gregory
2. Colbert
3. Lewis and Leaky
4. Dubois.

Answer: 2. Colbert

Question 68. Australopithecus African (African ape man) was discovered by

1. Leaky
2. Dubois
3. Raymon Dart
4. Lewis and Leaky.

Answer: 3. Raymon Dart

Question 69. Gregor discovered Homo sapiens fossils during the late Pleistocene period showed the following characters except:

1. Broad pelvic basin
2. Toolmaker
3. Face orthognathic
4. Cranial capacity 1200-1500 cm³.

Answer: 4. Cranial capacity 1200-1500 cm³

Question 70. Hominids include:

1. Homo sapiens
2. Chimpanzee ana gorilla
3. Orangutan and gibbons
4. Lemurs

Answer: 1. Homo sapiens

Origin Of Life Questions Multiple Choice Question and Answers

Question 1. Protobiogenesis occurred:

1. 1.2 billion years ago
2. 2.0 billion years ago
3. 2.5 billion years ago
4. More than 3.5 billion years ago.

Answer: 4. More than 3.5 billion years ago.

Question 2. Possible early sources of energy were:

1. Chlorophyll
2. CO₂
3. UV radiations and lightning
4. Green plants

Answer: 3. UV radiations and lightning

PSEB 12th Class Biology Origin of Life Questions with Answers

Question 3. One of the greatest advocates of the theory of special creation was:

1. C. Darwin
2. Aristotle
3. Father Saurez
4. Huxley.

Answer: 3. Father Saurez

Read and Learn More 12th Class Biology MCQs

Question 4. The theory of spontaneous generation was supported by:

1. Van Helmont
2. Redi
3. Spallanzani
4. Pasteur.

Answer: 1. Van Helmont

PSEB 12th Class Biology Origin of Life MCQs

Question 5. The most advanced theory of the origin of life is that of:

1. Catastrophic
2. Haldane and Oparin
3. Cosmozoic
4. Spontaneous.

Answer: 2. Haldane and Oparin

Question 6. First life on earth was:

1. Cyanobacteria
2. Chemoheterotrophs
3. Autotrophs
4. Photoautotrophs.

Answer: 2. Chemoheterotrophs

Question 7. There is no life on the moon because of the absence of:

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

Answer: 1. Water

Question 8. On the primitive earth, polymers such as proteins and nucleic acids in aqueous suspension formed the spherical aggregates, they are called:

1. Coacervates
2. Primitogens
3. Liposomes
4. Primitosomes.

Answer: 1. Coacervates

Question 9. Swan-necked flask experiment was done by:

1. Aristotle
2. Francisco Redi
3. Louis Pasteur
4. Robert Koch.

Answer: 3. Louis Pasteur

PSEB 12th Class Biology Origin of Life Questions with Answers

Question 10. The early atmosphere contained methane and other hydrocarbons. They have now been replaced by:

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

Answer: 3. Carbon dioxide

Question 11. Coacervates were experimentally produced by:

1. Urey and Miller
2. Oparin and Sydney Fox
3. Fisher and Huxley
4. Jacob and Monod.

Answer: 2. Oparin and Sydney Fox

Question 12. According to Oparin, which one of the following was not present in the primitive atmosphere of Earth?

1. Hydrogen
2. Water Vapour
3. Methane
4. Oxygen.

Answer: 4. Oxygen.

Origin of Life Multiple Choice Questions PSEB Class 12

Question 13. Which one of the following experiments suggests that the simplest living organisms could not have originated spontaneously from non-living matter?

1. Microbes did not appear in stored meat
2. Larvae could appear in decaying organic matter
3. Microbes appeared from unsterilized organic matter
4. The meat was not spoiled when heated and kept sealed in a vessel.

Answer: 4. Meat was not spoiled when heated and kept sealed in a vessel.

Question 14. One of the following plants has remained unchanged from the time of its origin:

1. Wheat
2. Ginkgo
3. Pea
4. Zea mays.

Answer: 2. Ginkgo

Question 15. The theory of special creation was supported by:

1. Van Helmont
2. Redi
3. Pasteur
4. Spallanzani.

Answer: 1. Van Helmont

Question 16. Oparin-Haldane theory of the origin of life states that:

1. Life originated as a result of physicochemical changes
2. Life originated from physical changes
3. Life originated by general changes
4. There is no origin of life.

Answer: 1. Life originated as a result of physicochemical changes

Question 17. Miller conducted his experiment in an apparatus containing methane, ammonia and hydrogen in the ratio of:

1. 5: 4: 1
2. 2 : 1: 2
3. 2:5:4
4. None of these.

Answer: 2. 2: 1: 2

Class 12 Biology Chapter Origin of Life

Question 18. Which one of the following amino acids was not found to be synthesized in Miller’s experiment?

1. Glycine
2. Aspartic acid
3. Glutamic acid
4. Alanine.

Answer: 3. Glutamic acid

Organisms and Populations Questions

Question 1. The keystone species in an ecosystem are those which:

1. Are present in a large number
2. Arc most frequent
3. Attain a large biomass
4. Contribute to ecosystem properties.

Answer: 4. Contribute to ecosystem properties.

Question 2. The sphere of living matter together with water, air, and soil on the earth is called:

1. Atmosphere
2. Hydrosphere
3. Lithosphere
4. Biosphere

Answer: 4. Biosphere

Question 3. Plants with irreversible and genetically fixed adaptations are known as :

1. Ecotypes
2. Ecotones
3. Ecophenes
4. Ecological Equivalents.

Answer: 1. Ecotypes

Read and Learn More 12th Class Biology MCQs

Question 4. Species which has a restricted distribution is called :

1. Endemic
2. Sympatric
3. Allopatric
4. Ecospecies

Answer: 1. Endemic

Organisms and Populations Class 12 Biology MCQs

Question 5. The study of communities, especially their environmental relationship, and structure, is known as

1. Autoecology
2. Synecology
3. Genecology
4. Phytosociology

Answer: 2. Synecology

Question 6. When the organisms live together in such a manner that one organism is benefited while the other remains unaffected. This type of association is called:

1. Commensalism
2. Symbiosis
3. Mutualism
4. Parasitism.

Answer: 1. Commensalism

Question 7. Plants and animals living in a given area form a:

1. Biome
2. Ecotone
3. Biotic community
4. Bioindicator.

Answer: 3. Biotic community

Question 8. The part of the earth and atmosphere supporting life is:

1. Biota
2. Biome
3. Ecotone
4. Biosphere

Answer: 4. Biosphere

Question 9. Which of the following is synecology?

1. Study of the same species
2. Study of different species
3. Both of these
4. None of these.

Answer: 2. Study of different species

Question 10. The term ‘biocoenosis’ was coined by:

1. Karl Mobius
2. Charles Darwin
3. E.P. Odum
4. E.Haeckel.

Answer: 4. E.Haeckel.

Question 11. A number of immigrants is more than emigration and deaths is lower than natality. The growth curve of the population will show:

1. Exponential phase
2. Lag phase
3. Declining phase
4. Steady phase.

Answer: 1. Exponential phase

Class 12 Biology Chapter Organisms and Populations MCQs

Question 12. Which one of the following has raised check bone, oblique eyes, and yellowish skin color

1. Negroids
2. Mongoloids
3. Polynesians
4. Caucasoids

Answer: 2. Mongoloids

Question 13. Scent-producing glands arc:

1. Anal glands
2. Adrenal glands
3. Bertholin’s gland
4. Prostate gland.

Answer: 1. Anal glands

Question 14. Pheromone is:

1. Product of endocrine gland
2. A protein
3. mRNA
4. Used for animal communication

Answer: 4. mRNA

Question 15. The percentage ratio of natality over mortality is:

1. Population dynamics
2. Vital index
3. Population density
4. Total count.

Answer: 2. Vital index

Question 16. The human population shows:

1. J-shaped growth curve
2. Z-shaped growth curve
3. S-shaped growth curve
4. All the above.

Answer: 3. S-shaped growth curve

Question 17. The process of mating of individuals which are more closely related than the average of the population to which they belong is called :

1. Inbreeding
2. Hybridization
3. Heterosis
4. Self-Breeding.

Answer: 1. Inbreeding

Question 18. Adaptation of a species is its :

1. Ecdysis
2. Metamorphosis
3. Acquired Character
4. Hereditary Character.

Answer: 4. Hereditary Character

Class 12 Biology Chapter Organisms and Populations MCQs

Question 19. The abundance of a species in a population, within its habitat, is called:

1. Atniche density
2. Absolute density
3. Relative density
4. Regional density.

Answer: 1. Atniche density

Question 20. Asymptote is a stage when a population is:

1. Stabilized
2. Changing
3. Increasing
4. Decreasing.

Answer: 1. Stabilised

Question 21. Two species cannot occupy the same niche. This law is known as:

1. Wien Law
2. Gause Law
3. Allen Law
4. Competition Exclusion Principle.

Answer: 2. Gause Law

Question 22. In which one of the following habitats, does the diurnal temperature of the soil surface vary most?

1. Forest
2. Desert
3. Grassland
4. Shrub land

Answer: 2. Desert

Question 23. Broad-leaved forest oaks are found in

1. North coniferous forests
2. Mediterranean evergreen forest
3. Temperate deciduous forests
4. Tropical deciduous forest.

Answer: 2. Mediterranean evergreen forest

Question 24. Prolonged liberal irrigation of agricultural fields is likely to create the problem of

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

Answer: 4. Salinity.

Question 25. At which latitude, does heat gain through insolation approximately equals heat loss through terrestrial radiation?

1. 66%° North and South
2. 22½° North and South
3. 421½° North and South
4. 40° North and South.

Answer: 3. 42½° North and South

Question 26. Animals have the innate ability to escape from predation. Examples for the same are given below. Select the incorrect example:

1. Colomuchange in chameleon
2. Melanism in moths
3. Poison fangs in snakes
4. Enlargement of body size by swallowing air in puffer fish.

Answer: 3. Poison fangs in snakes

Question 27. There exists a close association between the alga and the fungus within lichen. The fungus:

1. Fixes the atmospheric nitrogen for the alga
2. Provides protection, anchorage, and absorption for the alga
3. Releases oxygen for the alga
4. Provides food for the alga.

Answer: 2. Provides protection, anchorage, and absorption for the alga

State Board Class 12 Biology Organisms and Populations MCQs

Question 28. Identify the correctly matched pair:

1. Montreal Protocol – Global warming
2. Kyoto Protocol – Climatic change
3. Ramsar Convention – Groundwater pollution
4. Basal Convention – Biodiversity Conservation

Answer: 2. Kyoto Protocol – Climatic change

Question 29. The ability of the Venus fly trap to capture insects is, due to:

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

Answer: 4. Rapid turgor pressure changes.

Question 30. Sunderban contains mainly:

1. Mangrove plants
2. Alpine trees
3. Thick forest
4. Grass.

Answer: 1. Mangroove plants

Question 31. Pneumatophores are present/common in

1. Xerophytes
2. Hygrophytes
3. Mesophytes
4. Helopytes

Answer: 4. Helopytes

Question 32. Which one of the following correctly represents an organism and its ecological niche?

1. Vallisncria and pond
2. Desert locust (Scistoccrca)
3. Plant lice (aphids) and leaf
4. Vultures and dense forest.

Answer: 3. Plant lice (aphids) and leaf

Question 33. Humidity in the atmosphere decreases the rate of:

1. Transpiration
2. Photosynthesis
3. Glycolysis
4. Growth.

Answer: 1. Transpiration

Question 34. Niche overlap indicates:

1. Sharing of one or more resources between the two species
2. Mutualism between two species
3. Active cooperation between two species
4. Two different parasites on the same host.

Answer: 1. Sharing of one or more resources between the two species

State Board Class 12 Biology Organisms and Populations MCQs

Question 35. Annual migration does not occur in the case of:

1. Salamander
2. Salmon
3. Arctic tern
4. Siberian crane.

Answer: 1. Salamander

Question 36. Choose the correct combination of labeling of the zones in water in a lake.

1. a-Limnetic zone, b-Profoundal zone, c-Littoral zone, d-Benthic zone
2. a-Littoral zone, b-Benthic zone, c-Profundal zone, d-Limnetic zone
3. a-Littoral zone, b-Limnetic zone, c-Profundal zone, d-Benthic zone
4. a-Limnetic zone, b-Littoral zone, c-Benthic zone, d-profundal zone
5. a-Littoral zone, b-Profundal zone, c-Benthic zone, d-Limnetic zone.

Answer: 3. a-Littoral zone, b-Limnetic zone, c-Profundal zone, d-Benthic zone

Question 37. Geometric representation of age structure is a characteristic of

1. Population
2. Landscape
3. Ecosystem
4. Biotic community.

Answer: 1. Population

Question 38. The population of an insect species shows an explosive increase in number during rainy season followed by its disappearance at the end of the season. What does this show?

1. The food plants mat arc and die at the end of the rainy season.
2. Its population growth curve is of J-type.
3. The population of its predators increases enormously
4. S-shaped or sigmoid growth of this insect.

Answer: 2. Its population growth curve is of J-type.

Question 39. Which one of the following is categorized as a parasite in the true sense?

1. The female Anopheles bites and sucks blood from humans
2. A human fetus developing inside the uterus draws nourishment from the mother
3. Head louse living on the human scalp as well as laying eggs on human hair
4. The cuckoo (koel) lays its eggs in a crow’s nest.

Answer: 3. Head louse living on the human scalp as well as laying eggs on human hair

Question 40. Consider the following four conditions (1 – 4) and select die correct pair of them as adaptation to the environment in desert lizards. The conditions:

1. Burrowing in soil to escape high-temperature
2. Losing heat rapidly from the body during high-temperature
3. Bask in the sun when the temperature is low
4. The insulating body is due, to the thick fatty dermis.

Options:

1. (3), (4)
2. (1), (3)
3. (2), (4)
4. (1), (2)

Answer: 2. (1), (3)

State Board Class 12 Biology Organisms and Populations MCQs

Question 41. What type of human population is represented by the following age pyramid?

1. Vanishing population
2. Stable population
3. Declining population
4. Expanding population

Answer: 3. Declining population

Question 42. People, who migrated from the planes to an area adjoining Rohtang Pass about six months back:

1. Are not physically fit to play games like football.
2. Suffer from altitude sickness with symptoms like nausea, fatigue, etc.
3. Have the usual RBC count but their haemoglobin has a very high binding affinity to O₂
4. Have more RBCs and their haemoglobin has a lower binding affinity to O₂

Answer: 4. Have more RBCs and their hemoglobin has a lower binding affinity to O₂

Question 43. The fungal association of roots of higher plants in mycorrhiza is known as :

1. Parasitism
2. Hyperparasitism
3. Mutualism
4. Commensalism.

Answer: 3. Mutualism

Question 44. Hyperparasite is a kind of parasite which:

1. Kills its host
2. Completes life cycle in one host
3. Uses host machinery for reproduction
4. None of the above.

Answer: 4. None of the above.

Question 45. Plants obtaining nourishment from other plants by haustoria are:

1. Mcsophytes
2. Parasites
3. Xerophytes
4. Halophytes.

Answer: 2. Parasites

Question 46. A successful parasite is the one which

1. Grows rapidly
2. Reproduces last
3. Sdcks to host for a long
4. Makes minimum demands from its host.

Answer: 4. Makes minimum demands from its host.

Question 47. Which of the following statements is correct regarding the two organisms in commensalism?

1. No one is harmed
2. Both partners are harmed
3. One partner benefits whether another suffers partner benefits and the other remains unharmed.
4. Answer: 4. One partner benefited while another suffering partner benefited and the other remains unharmed.

Organisms and Populations MCQs with Answers Class 12

Question 48. Which is not characteristic of intestinal symbionts?

1. Feeding on extra food of the host
2. Providing vitamins to host
3. Anaerobic respiration
4. Aerobic respiration.

Answer: 4. Aerobic respiration

Question 49. Ecological succession on sand is:

1. Timomere
2. Xerosere
3. Halosere
4. Hydrosere

Answer: 1. Timomere

Question 50. The cause of mimicry is

1. Concealment
2. Offense
3. Defense
4. Both (2) And (3).

Answer: 1. Concealment

Question 51. Which of the following insects mimics thin dry branches of the plant on which it lives?

1. KaIlima parallactic
2. Mantis religiosa
3. Phyllium frondosum
4. Caraitstusmorosus.

Answer: 2. Mantis religiosa

Question 52. The individual that shows mimicry is called:

1. Mimic
2. Predator
3. Prey
4. Parasite

Answer: 1. Mimic

Question 53. Heterodon flattens its head and produces frequent hissing and strikes to advertise as if it is dangerous. This is an example of:

1. Alluring mimicry
2. Warning mimicry
3. Concealing mimicry
4. Batesian mimicry.

Answer: 2. Warning mimicry

Question 54. In conscious mimicry:

1. The organisms behave as if they are dead bodies
2. The organisms become more conscious
3. The organism catches its prey with great ease
4. None of the above.

Answer: 1. The organisms behave as if they are dead bodies

Question 55. Which of the following resembles a dry leaf?

1. Phyllium
2. Paralectci
3. Cryptolithodes
4. Pap ilia machaon.

Answer: 2. Paralectci

Question 56. July 11 is observed as:

1. No tobacco day
2. World health day
3. World population day
4. World environment day

Answer: 4. World Environment Day

Organisms and Populations MCQs with Answers Class 12

Question 57. Which among the following is the primary function of mimicry prevalent in some animals?

1. Warning
2. Concealment
3. Allurement
4. Aggression.

Answer: 2. Concealment

Question 58. Succession in an ecosystem is the result of:

1. Occurrence of diseases
2. Changes in grazing habits of animals
3. Competition among animals
4. Adaptive ability to environmental changes.

Answer: 4. Adaptive ability to environmental changes

Question 59. Mycorrhiza is an example of:

1. Decomposers
2. Endoparasitism
3. Symbiotic relationship
4. Ectoparasitism.

Answer: 3. Symbiotic relationship

Question 60. Two opposite forces operate in the growth and development of every population. One of them relates to the ability to reproduce at a given rate. The force opposing it is called :

1. Morbidity
2. Biotic potential
3. Fecundity
4. Environmental resistance

Answer: 4. Environmental resistance

Question 61. Maximum growth rate occurs in:

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

Answer: 3. Exponential Phase

Question 62. Lichens are a well-known combination of an alga and a fungus where the fungus has:

1. An epiphytic relationship with the alga
2. A parasitic relationship with the alga
3. Symbiotic relationship with the alga
4. A saprophytic relationship with alga.

Answer: 3. Symbiotic relationship with the alga

Organisms and Populations MCQs with Answers Class 12

Question 63. An ecosystem that can be easily damaged but can recover after some time if the damaging effect stops will have the following:

1. High stability and low resistance
2. Low stability and low resistance
3. High stability and high resistance
4. Low stability and high resistance.

Answer: 1. High stability and low resistance

Question 64. A terrestrial animal must be able to:

1. Actively pump salts out through the skin
2. Excrete large amounts of salts in urine
3. Excrete a large amount of water in urine
4. Conserve water.

Answer: 4. Conserve water.

Question 65. What is a keystone species?

1. A common species that has plenty of biomass yet has a fairly low impact on the community’s organization
2. A rare species that has minimal impact on the biomass and no other species in the community
3. A dominant species that constitutes a large proportion of the biomass and which affects many other species
4. A species that makes only a small proportion of the total biomass of a community yet has a huge impact on the community’s organization and survival.

Answer: 4. A species that makes only a small proportion of the total biomass of a community, yet has a huge impact on a community’s organization and survival.

Question 66. The most thoroughly studied of the known bacteria-plant interaction is the:

1. Nodulation of Sesbania stems by N₂ fixing bacteria
2. Plant growth stimulation by phosphate-solubilizing bacteria
3. Cyanobacterial symbiosis with some aquatic ferns
4. Gall formation on certain angiosperms by Agrobacterium.

Answer: 4. Gall formation on certain angiosperms by Agrobacterium.

Question 67. A term used to describe non-dominant species that dictate community structure is:

1. Pioneer species
2. Exogenous species
3. Keystone species
4. Transitional species.

Answer: 3. Keystone species

Question 68. In succession, complexities in structure:

1. Drastically increase
2. Slowly increase
3. Does not increase
4. Constant.

Answer: 2. Slowly increase

Question 69. The presence of diversity at the junction of territories of two different habitats is known as

1. Bottleneck effect
2. Edge effect
3. Junction effect
4. Pasteur effect.

Answer: 2. Edge effect

Question 70. Small fish get stuck near the bottom of a shark and derive its nutrition from it. This kind of association is called as:

1. Symbiosis
2. Commensalism
3. Predation
4. Parasitism.

Answer: 2. Commensalism

Question 71. A praying mantis is a good example of:

1. Social insects
2. Camouflage
3. Mullerian mimicry
4. Warning coloration.

Answer: 2. Camouflage

Question 72. The formula for exponential population growth is:

1. rN/dN = dt
2. dN/dt = rN
3. dt/dN = rN
4. dN/rN = dt.

Answer: 2. dN/dt = rN

Question 73. Match the following with the correct combination:

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

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

Question 74. Find out the correct order of succession levels in xerarch.

1. Lichen moss stage, annual herb stage, perennial herb stage, scrub stage, forest
2. Annual herb stage, perennial herb stage, lichen moss stage, scrub stage, forest
3. Perennial herb stage, annual herb stage, lichen moss stage, scrub stage, forest
4. Scrub stage, forest, annual herb stage, perennial herb stage, lichen moss stage
5. Forest, scrub stage, annual stage, perennial herb stage, lichen moss stage.

Answer: 1. Lichen moss stage, annual herb stage, perennial herb stage, scrub stage, forest

Organisms and Populations MCQs with Answers Class 12

Question 75. The concept of chemical evolution is based on:

1. Interaction of water, air, and clay under intense heat
2. Effect of solar radiation on chemicals
3. Possible origin of life by combination of chemicals under suitable environmental conditions
4. Crystallization of chemicals.

Answer: 3. Possible origin of life by a combination of chemicals under suitable environmental conditions

Question 76. If the mean and the median pertaining to a certain character of a population are of the same value, the following is most likely to occur:

1. A bimodal distribution
2. A T-shaped curve
3. A skewed curve
4. A normal distribution.

Answer: 4. A normal distribution.

Question 77 The equation \(\frac{\Delta N_n}{\Delta N}\) represents which of the following?

1. Natality
2. Growth rate
3. Mortality
4. All of these.

Answer: 2. Growth rate

Question 78. The change in population size at a given time interval t, is given by the expression N_t = N₀ + I – D – E, I, B, and D stand respectively for

1. Rate of immigration, mortality rate, natality rate
2. Rate of emigration, natality rate, mortality rate
3. Mortality rate, natality rate, rate of immigration
4. Mortality rate, rate of immigration, natality rate
5. Rate of immigration, natality rate, mortality rate.

Answer: 5. Rate of immigration, natality rate, mortality rate.

Question 79. Which one of the following is considered as pioneer community in xerarch?

1. Annual herb
2. Perennial herb
3. Scrub stage
4. Forest stage
5. Lichen

Answer: 5. Lichen

Question 80. Which one of the following statements is correct for secondary succession?

1. It begins on a bare rock
2. It occurs on a deforested site
3. It follows a primary succession
4. It is similar to primary succession except that it has a relatively fast pace.

Answer: 2. It occurs on a deforested site

Question 81. A sedentary sea anemone gets attached to the shell lining of a hermit crab. The association is:

1. Symbiosis
2. Commensalism
3. Amensalism
4. Ectoparasitism

Answer: 2. Commensalism

Question 82. A biologist studied the population of rats in a bam. He found that the average natality was 250, average mortality was 240, immigration was 20, and emigration 30. The net increase in population is:

1. 15
2. 05
3. Zero
4. 10

Answer: 3. Zero