MCQs on Evolution – Class 12 Biology (NCERT Based)

Course: CBSE Class 12 Biology
Unit II: Genetics and Evolution
Topic: Evolution
Strictly as per NCERT | CBSE Board Exam Oriented | Concept-Clearing Explanations

Section A: Origin of Life and Evidences of Evolution (Q1–Q15)

Q1. The theory of chemical evolution was proposed by

A. Darwin
B. Lamarck
C. Oparin and Haldane
D. Miller

Correct Answer: C
Explanation: Oparin and Haldane proposed that life originated from non-living organic molecules through chemical evolution under primitive Earth conditions.

Q2. The Miller–Urey experiment provided evidence for

A. biological evolution
B. origin of species
C. chemical evolution
D. natural selection

Correct Answer: C
Explanation: The experiment demonstrated synthesis of organic molecules like amino acids from inorganic substances.

Q3. Which of the following is the oldest era of Earth?

A. Mesozoic
B. Paleozoic
C. Cenozoic
D. Precambrian

Correct Answer: D
Explanation: Precambrian era represents the earliest period of Earth’s history.

Q4. Homologous organs indicate

A. analogous evolution
B. convergent evolution
C. common ancestry
D. adaptive radiation

Correct Answer: C
Explanation: Homologous organs have similar origin but different functions, indicating common ancestry.

Q5. Analogous organs show

A. same origin, same function
B. same origin, different function
C. different origin, same function
D. different origin, different function

Correct Answer: C
Explanation: Analogous organs evolve independently to perform similar functions.

Q6. Which is an example of homologous organs?

A. Wings of butterfly and bird
B. Forelimbs of human and whale
C. Eyes of octopus and mammals
D. Wings of bat and insect

Correct Answer: B
Explanation: Forelimbs of human and whale have similar structural plan and origin.

Q7. Fossils provide evidence for

A. mutation
B. genetic drift
C. organic evolution
D. isolation

Correct Answer: C
Explanation: Fossils show gradual changes in organisms over geological time.

Q8. Connecting link between reptiles and birds is

A. Archaeopteryx
B. Ichthyosaurus
C. Peripatus
D. Seymouria

Correct Answer: A
Explanation: Archaeopteryx shows characteristics of both reptiles and birds.

Q9. Vestigial organs are

A. functional organs
B. newly evolved organs
C. reduced and non-functional organs
D. adaptive organs

Correct Answer: C
Explanation: Vestigial organs have lost their original function through evolution.

Q10. Wings of bat and bird represent

A. homologous organs
B. analogous organs
C. vestigial organs
D. connecting links

Correct Answer: A
Explanation: Both wings have same basic skeletal structure, showing common origin.

Q11. Evolutionary history of organisms is called

A. phylogeny
B. ontogeny
C. taxonomy
D. ecology

Correct Answer: A
Explanation: Phylogeny refers to the evolutionary relationships among organisms.

Q12. Which evidence supports chemical evolution?

A. Fossils
B. Homology
C. Miller experiment
D. Embryology

Correct Answer: C
Explanation: Miller’s experiment showed abiotic synthesis of organic compounds.

Q13. Which structure in humans is vestigial?

A. Heart
B. Appendix
C. Kidney
D. Liver

Correct Answer: B
Explanation: Appendix is reduced and non-functional in humans.

Q14. Comparative embryology supports evolution because

A. embryos are different
B. embryos show similarities
C. adults are similar
D. fossils are present

Correct Answer: B
Explanation: Similar embryonic stages suggest common ancestry.

Q15. Adaptive radiation is best seen in

A. dinosaurs
B. Australian marsupials
C. bacteria
D. fungi

Correct Answer: B
Explanation: Australian marsupials diversified from a common ancestor into various forms.

Section B: Theories of Evolution and Natural Selection (Q16–Q30)

Q16. The theory of natural selection was proposed by

A. Lamarck
B. Darwin
C. De Vries
D. Mendel

Correct Answer: B
Explanation: Charles Darwin proposed natural selection as the mechanism of evolution.

Q17. According to Darwin, evolution occurs due to

A. inheritance of acquired characters
B. sudden mutations
C. natural selection
D. isolation alone

Correct Answer: C
Explanation: Natural selection favors survival of the fittest individuals.

Q18. Lamarck’s theory is based on

A. natural selection
B. acquired characters
C. mutation
D. genetic drift

Correct Answer: B
Explanation: Lamarck believed acquired traits are inherited.

Q19. The idea of use and disuse of organs was proposed by

A. Darwin
B. Wallace
C. Lamarck
D. Mendel

Correct Answer: C
Explanation: Lamarck proposed that frequently used organs become stronger.

Q20. The theory of mutation was proposed by

A. Darwin
B. Lamarck
C. De Vries
D. Wallace

Correct Answer: C
Explanation: Hugo de Vries suggested evolution occurs due to sudden mutations.

Q21. Survival of the fittest means

A. strongest organism survives
B. organism best adapted survives
C. largest organism survives
D. fastest organism survives

Correct Answer: B
Explanation: Fitness refers to reproductive success in a given environment.

Q22. Which factor does NOT affect evolution?

A. Mutation
B. Gene flow
C. Natural selection
D. Mitosis

Correct Answer: D
Explanation: Mitosis does not create variation in populations.

Q23. Industrial melanism was observed in

A. humans
B. peppered moth
C. fruit fly
D. frog

Correct Answer: B
Explanation: Dark-colored moths survived better in polluted areas.

Q24. Industrial melanism supports

A. mutation theory
B. inheritance of acquired characters
C. natural selection
D. genetic drift

Correct Answer: C
Explanation: Environmental change favored dark moths through natural selection.

Q25. Which organism shows rapid evolution?

A. Humans
B. Bacteria
C. Trees
D. Elephants

Correct Answer: B
Explanation: Short life cycle allows bacteria to evolve rapidly.

Q26. Gene flow occurs due to

A. mutation
B. migration
C. selection
D. isolation

Correct Answer: B
Explanation: Movement of individuals causes transfer of genes between populations.

Q27. Genetic drift is more effective in

A. large populations
B. small populations
C. stable populations
D. ancient species

Correct Answer: B
Explanation: Random changes are more pronounced in small populations.

Q28. Bottleneck effect is an example of

A. natural selection
B. genetic drift
C. mutation
D. recombination

Correct Answer: B
Explanation: Sudden reduction in population alters gene frequency randomly.

Q29. Founder effect occurs when

A. large population migrates
B. new population is formed by few individuals
C. mutation rate increases
D. selection stops

Correct Answer: B
Explanation: Limited genetic variation results in founder populations.

Q30. Which theory is no longer accepted?

A. Natural selection
B. Synthetic theory
C. Mutation theory
D. Inheritance of acquired characters

Correct Answer: D
Explanation: Acquired traits are not inherited genetically.

Section C: Speciation, Hardy–Weinberg Principle and Human Evolution (Q31–Q50)

Q31. Formation of new species is called

A. evolution
B. variation
C. speciation
D. adaptation

Correct Answer: C
Explanation: Speciation refers to the formation of new species.

Q32. Reproductive isolation is essential for

A. mutation
B. speciation
C. migration
D. adaptation

Correct Answer: B
Explanation: Isolation prevents gene flow, leading to new species formation.

Q33. Hardy–Weinberg principle states that

A. population evolves constantly
B. allele frequencies remain constant
C. mutations are frequent
D. natural selection stops

Correct Answer: B
Explanation: Allele frequencies remain stable in absence of evolutionary forces.

Q34. The equation p² + 2pq + q² = 1 represents

A. mutation rate
B. gene flow
C. Hardy–Weinberg equilibrium
D. genetic drift

Correct Answer: C
Explanation: It represents genotype frequencies in a stable population.

Q35. Which factor disturbs Hardy–Weinberg equilibrium?

A. Random mating
B. Large population
C. No migration
D. Mutation

Correct Answer: D
Explanation: Mutation changes allele frequencies, disturbing equilibrium.

Q36. Homo sapiens originated in

A. Asia
B. Europe
C. Africa
D. Australia

Correct Answer: C
Explanation: Fossil evidence indicates African origin of modern humans.

Q37. Neanderthal man lived in

A. Africa
B. Europe
C. Australia
D. America

Correct Answer: B
Explanation: Neanderthals inhabited Europe and West Asia.

Q38. Tool making was first seen in

A. Homo sapiens
B. Homo habilis
C. Homo erectus
D. Australopithecus

Correct Answer: B
Explanation: Homo habilis was known as the handyman.

Q39. Brain size increased significantly in

A. Australopithecus
B. Homo habilis
C. Homo erectus
D. Homo sapiens

Correct Answer: C
Explanation: Homo erectus showed a significant increase in brain size.

Q40. Modern humans belong to

A. Homo habilis
B. Homo erectus
C. Homo sapiens sapiens
D. Australopithecus

Correct Answer: C
Explanation: Homo sapiens sapiens represents modern humans.

Q41. Evolution is a

A. linear process
B. random process without direction
C. gradual process
D. sudden process only

Correct Answer: C
Explanation: Evolution generally occurs gradually over generations.

Q42. Which is NOT a mechanism of evolution?

A. Mutation
B. Natural selection
C. Genetic drift
D. Mitosis

Correct Answer: D
Explanation: Mitosis does not alter genetic composition of populations.

Q43. Adaptive radiation results in

A. extinction
B. speciation
C. genetic drift
D. isolation

Correct Answer: B
Explanation: Adaptive radiation produces multiple species from a common ancestor.

Q44. The study of fossils is called

A. paleontology
B. archaeology
C. anthropology
D. ecology

Correct Answer: A
Explanation: Paleontology deals with study of fossils.

Q45. Which hominid used fire?

A. Homo habilis
B. Homo erectus
C. Australopithecus
D. Neanderthal

Correct Answer: B
Explanation: Homo erectus is believed to have used fire.

Q46. Speciation due to geographical isolation is called

A. sympatric
B. parapatric
C. allopatric
D. adaptive

Correct Answer: C
Explanation: Allopatric speciation occurs due to physical barriers.

Q47. The modern synthetic theory of evolution combines

A. Darwin and Lamarck
B. mutation and selection
C. genetics and natural selection
D. paleontology and ecology

Correct Answer: C
Explanation: It integrates Mendelian genetics with Darwinian selection.

Q48. Which is the driving force of evolution?

A. Isolation
B. Mutation
C. Natural selection
D. Gene flow

Correct Answer: C
Explanation: Natural selection directs evolution by favoring beneficial traits.

Q49. Human evolution shows that humans evolved from

A. monkeys
B. apes
C. common ancestors
D. gorillas

Correct Answer: C
Explanation: Humans and apes share a common ancestor.

Q50. Evolution is best described as

A. change in individual
B. change in population over time
C. sudden appearance of species
D. extinction only

Correct Answer: B
Explanation: Evolution refers to genetic changes in populations across generations.