Evolution of Life

VidyaarOctober 23, 2026073 views

Q60. Small differences accumulating among individuals over generations eventually produce new life forms. What does this illustrate?

[RRB Group D, 12 August 2026, Shift 1]

(A) Ecological succession

(B) Evolution of biodiversity

(D) Genetic drift

Answer: (B) Evolution of biodiversity

Explanation: Evolutionary biodiversity develops as inherited differences accumulate and populations diverge over successive generations. New traits can affect survival and reproduction. Ecological succession changes the community occupying a place, whereas classification merely organises known forms and genetic drift is one particular evolutionary mechanism.

[RRB Group D, 11 August 2026, Shift 3]

(A) Activity patterns

(B) Feeding habits

(D) Similarity in genetic code

Answer: (D) Similarity in genetic code

Explanation: Comparisons of DNA sequences and shared genetic information provide strong evidence of ancestry because genes are transmitted across generations. Superficially similar body shapes or feeding habits may develop independently through convergent evolution and are therefore less reliable on their own.

Q58. Match evolutionary events with their approximate times:
A. Dinosaur extinction (65 mya);
B. Invertebrates active (500 mya);
C. Jawless fish (350 mya);
D. Seaweeds and plants (320 mya).

[NEET UG, 3 May 2026]

(A) A–extinction, B–invertebrates, C–jawless fish, D–seaweeds/plants

(B) A–jawless fish, B–invertebrates, C–extinction, D–seaweeds/plants

(D) A–seaweeds/plants, B–jawless fish, C–invertebrates, D–extinction

Answer: (A) A–extinction, B–invertebrates, C–jawless fish, D–seaweeds/plants

Explanation: The examination uses approximate dates from a conventional textbook chronology. Its pairings place dinosaur extinction at about 65 million years, active invertebrates around 500 million years, jawless fish around 350 million years and selected plant groups around 320 million years ago.

Q57. What is the chief advantage of combining DNA from two parents during sexual reproduction?

[RRB Group D, 10 February 2026, Shift 1]

(A) It eliminates the need for reproductive organs

(B) It prevents errors in DNA copying

(D) It makes reproduction necessarily faster

Answer: (C) It increases genetic variation in the population

Explanation: Combining parental genomes generates new allele combinations through meiosis, recombination and fertilisation. This supplies heritable diversity on which natural selection can act. Although reproduction has other benefits and costs, it does not completely eliminate copying errors or make reproduction universally faster.

Q56. What does variation among individuals of a species help to ensure?

[RRB Group D, 4 February 2026, Shift 3]

(A) Absence of mutations

(B) Greater adaptability and survival chances

(D) Identical responses to environmental change

Answer: (B) Greater adaptability and survival chances

Explanation: Variation means that individuals possess different inherited characteristics. When environments change, some variants may cope better with the new conditions and leave more offspring. This increases the capacity of populations to persist, although no single trait guarantees survival everywhere.

Q55. Why can sexual reproduction improve survival prospects among the offspring of plants?

[RRB Group D, 4 February 2026, Shift 1]

(A) Offspring possess new genetic recombinations

(B) Offspring never display variation

(D) Offspring always develop more rapidly

Answer: (A) Offspring possess new genetic recombinations

Explanation: Meiosis generates new genetic combinations through crossing-over and independent assortment; fertilisation further mixes parental alleles. Such diversity may give some descendants an advantage under changing conditions. Clones, by contrast, preserve much more of the parental genetic combination.

Q54. Why is variation important in a population when environmental conditions change?

[RRB Group D, 3 February 2026, Shift 2]

(A) It inevitably causes complete extinction

(B) It makes every organism identical

(D) It stops reproduction

Answer: (C) Some individuals may survive due to favourable differences

Explanation: Environmental stress rarely affects every genotype equally. A variant that is advantageous under a new disease, climate or food supply can enable its bearer to survive and reproduce. Population-level evolution results when such inherited variants change in frequency over generations.

Q53. Which is a long-term outcome of the variation created by sexual reproduction?

[RRB Group D, 2 February 2026, Shift 3]

(A) Evolution

(B) Formation of identical twins in every pregnancy

(D) Reduced chances of survival in every case

Answer: (A) Evolution

Explanation: Sexual reproduction shuffles existing alleles, generating differences among offspring. Inherited variation provides the raw material for natural selection and other mechanisms that alter populations over time. Therefore, it contributes to evolution rather than guaranteeing genetically identical descendants.

Q52. Who wrote The Origin of Species by Means of Natural Selection?

[NDA II, General Ability Test, 14 September 2025]

(A) Charles Darwin

(B) Carolus Linnaeus

(D) Nicolaus Copernicus

Answer: (A) Charles Darwin

Explanation: Charles Darwin published On the Origin of Species in 1859, providing a detailed argument for evolution by natural selection. Linnaeus pioneered biological classification, McClintock discovered transposable genetic elements, and Copernicus advanced the heliocentric account of the solar system.

Q51. How is evolutionary biology useful in contemporary medicine?

[MP Excise Constable, 13 September 2025, Shift 1]

(A) It helps explain genetic disorders and antibiotic resistance

(B) It establishes supernatural causes for every disease

(D) It proves that species never change

Answer: (A) It helps explain genetic disorders and antibiotic resistance

Explanation: Evolutionary ideas illuminate how pathogens become resistant under drug selection and why harmful gene variants persist in populations. They also clarify disease susceptibility and host–parasite interactions. This approach complements genetics, microbiology and physiology; it does not replace those disciplines.

Q50. Which description fits the primitive atmosphere proposed in the Oparin–Haldane hypothesis?

[CSIR–UGC NET Life Sciences, 28 July 2025]

(A) Abundant oxygen and nitrogen

(B) Predominantly carbon dioxide and oxygen

(D) Essentially the same as today’s atmosphere

Answer: (C) A reducing mixture including methane and ammonia

Explanation: Oparin and Haldane envisaged a prebiotic environment lacking free molecular oxygen and containing reducing gases. Energy from lightning or radiation could generate organic compounds from simpler ingredients. The hypothesis is historically important even though details of the actual early atmosphere remain debated.

Q49. Sweet potato and ordinary potato exemplify which evolutionary relationship?

[NEET UG, 4 May 2025]

(A) Analogy and convergent evolution

(B) Homology and divergent evolution

(D) Analogy and divergent evolution

Answer: (A) Analogy and convergent evolution

Explanation: Both store food, but sweet potato is a modified root whereas ordinary potato is a modified stem. Similar functions evolved in organs of different anatomical origin; this is analogy, commonly used to illustrate convergent rather than divergent evolution.

Q48. Which central idea was developed in Darwin’s The Descent of Man?

[MP Police Constable, 13 December 2025, Shift 1]

(A) Genetic migration alone

(B) Human evolution and common ancestry

(D) Geological origin of Earth

Answer: (B) Human evolution and common ancestry

Explanation: Published in 1871, The Descent of Man extended evolutionary explanation to humans and considered their relationships with other organisms. Darwin also discussed sexual selection. It was not primarily a treatise on the chemical emergence of life or the formation of Earth.

Q47. In the Hardy–Weinberg expression, what do p and q represent for a two-allele gene?

[MP Police Constable, 11 December 2025, Shift 2]

(A) Both frequencies of the same dominant allele

(B) p recessive allele frequency and q dominant allele frequency

(D) Both frequencies of dominant alleles at separate genes

Answer: (C) p dominant allele frequency and q recessive allele frequency

Explanation: In the usual notation for two alleles, p and q denote their respective frequencies, with p + q = 1. Dominance is merely a label in this question; mathematically the equation works regardless of which allele is dominant.

Q46. What was a major limitation of Darwin’s original theory of evolution?

[MP Police Constable, 6 December 2025, Shift 2]

(A) It exaggerated the ability to reproduce

(B) It did not adequately explain heredity and the origin of variations

(D) It could not recognise any vestigial organ

Answer: (B) It did not adequately explain heredity and the origin of variations

Explanation: Darwin described natural selection convincingly but lacked Mendelian genetics and knowledge of DNA, mutation and recombination. Consequently, the transmission and production of inherited variation were poorly understood. Modern evolutionary synthesis integrated these genetic mechanisms with Darwinian selection.

Q45. Which statement about Homo sapiens and Neanderthals is NOT correct?

[MP Police Constable, 1 November 2025, Shift 1]

(A) Genetic evidence indicates that they interbred

(B) Modern humans had the robust, cold-adapted build while Neanderthals were generally leaner

(D) Modern humans later developed agriculture

Answer: (B) Modern humans had the robust, cold-adapted build while Neanderthals were generally leaner

Explanation: Neanderthals typically possessed robust skeletons and relatively short distal limbs, features associated with cold adaptation. Modern humans showed different average body proportions. Genome evidence also documents interbreeding, so completely separate and noninteracting evolutionary histories would be misleading.

Q44. In which year were the famous Homo erectus remains known as Java Man first discovered?

[MP Police Constable, 30 October 2025, Shift 1]

(A) 1860

(B) 1890

(D) 1891

Answer: (D) 1891

Explanation: Dutch researcher Eugène Dubois uncovered important early human fossils in Java in 1891. The finds eventually became associated with Homo erectus and strengthened the fossil evidence for human evolution. Discovery dates should be distinguished from later classification and re-examination of the remains.

Q43. Salkhan Fossil Park, known for ancient life evidence, lies in which Indian state?

[SSC CHSL Tier I, 29 November 2025, Shift 2]

(A) Uttar Pradesh

(B) Madhya Pradesh

(D) Kerala

Answer: (A) Uttar Pradesh

Explanation: Salkhan Fossil Park is in Sonbhadra district of Uttar Pradesh. Its ancient stromatolite-bearing formations preserve evidence associated with microbial communities. Such structures are important for interpreting the activity of early life and environments long before complex animals appeared.

Q42. Which member of the phylum Porifera is the oldest metazoan group still existing on our planet?

[SSC GD Constable, 10 February 2025, Shift 3]

(A) Sea anemones

(B) Sycon

(D) Sponges

Answer: (D) Sponges

Explanation: Sponges, belonging to Porifera, are among the earliest-diverging animal lineages and have an ancient fossil history. Their cells are specialised but true tissues and organs are absent. These simple animals are important to understanding the early evolution of multicellular organisms.

Q41. What is regarded as the basic unit of evolutionary change?

[JKSSB Veterinary Pharmacist, 2 March 2025]

(A) Individual

(B) Social group

(D) Single organism’s body part

Answer: (C) Population

Explanation: Evolution is measured as a change in inherited genetic composition, usually allele frequencies, over generations. A population has a gene pool whose frequencies can change. Individuals may be selected, but their inherited genotype does not evolve across successive generations within one lifetime.

Q40. Which organism is the classic example used to explain industrial melanism?

[JKSSB Veterinary Pharmacist, 2 March 2025]

(A) Peppered moth (Biston betularia)

(B) Darwin’s finches

(D) Freshwater turtle

Answer: (A) Peppered moth (Biston betularia)

Explanation: In polluted environments, dark peppered moths gained a camouflage advantage on soot-darkened tree trunks. In cleaner habitats, lighter forms could be less conspicuous. The shifting colour frequencies illustrate natural selection acting on existing inherited variation.

Q39. Which geological discipline studies fossils and ancient living organisms?

[SSC Selection Post, Higher Secondary, 26 July 2025, Shift 2]

(A) Petrology

(B) Mineralogy

(D) Geochronology

Answer: (C) Palaeontology

Explanation: Palaeontology examines fossils, including preserved bodies, impressions and traces, to reconstruct the history of life. Fossils reveal extinct forms, anatomical transitions and former ecosystems. Geochronology concentrates on establishing ages, whereas petrology and mineralogy focus on rocks and minerals.

Q38. Match: A. Living fossil; B. Connecting link; C. Vestigial organ; D. Atavism,

with I. Enlarged canine teeth; II. Vermiform appendix; III. Echidna; IV. Latimeria.

[NEET UG, 23 June 2024]

(A) A–IV, B–III, C–II, D–I

(B) A–IV, B–II, C–III, D–I

(D) A–III, B–IV, C–I, D–II

Answer: (A) A–IV, B–III, C–II, D–I

Explanation: Latimeria is often termed a living fossil, while Echidna combines egg-laying with mammalian characteristics. The human appendix is traditionally taught as vestigial, though it retains immune functions. Atavism refers to the reappearance of ancestral traits such as enlarged canines.

Q37. Which branch reconstructs ancient environments and their relations with past organisms?

[SSC CGL Tier I, 18 September 2024, Shift 2]

(A) Demecology

(B) Ichthyology

(D) Mycology

Answer: (C) Palaeoecology

Explanation: Palaeoecology uses fossil assemblages, sediments and geological context to reconstruct earlier ecosystems and their ecological interactions. This helps reveal environmental pressures and evolutionary changes. Demecology concerns populations, ichthyology concerns fishes, and mycology concerns fungi.

Q36. Who described the idea of evolution in the book The Origin of Species?

[SSC MTS (2022 cycle), 9 May 2023, Shift 2]

(A) Edward Jenner

(B) Charles Darwin

(D) Aristotle

Answer: (B) Charles Darwin

Explanation: Charles Darwin presented evidence for descent with modification in his 1859 book On the Origin of Species. He proposed natural selection as a major mechanism. Jenner developed vaccination, Robert Brown described the cell nucleus, and Aristotle contributed to early natural history.

Q35. Which gas was considered absent from Earth’s primitive atmosphere in Oparin’s account?

[Bihar Secondary Teacher, Science, 26 August 2023]

(A) Free oxygen

(B) Hydrogen

(D) More than one of the above

(E) None of the above

Answer: (A) Free oxygen

Explanation: The classical chemical-evolution hypothesis assumes a primitive atmosphere without appreciable free oxygen, thereby permitting reactions involving reduced carbon and nitrogen compounds. Oxygen became abundant much later through biological photosynthesis. Modern reconstructions of the early atmosphere are more nuanced than the original model.

Q34. Which expression gives Hardy–Weinberg genotype frequencies for two alleles?

[Bihar STET PGT Zoology, 13 September 2023]

(A) p² + pq + q² = 0

(B) p² + pq + q² = 1

(D) p² + 2pq + q² = 1

Answer: (D) p² + 2pq + q² = 1

Explanation: If p and q are the frequencies of two alleles, then p + q equals one. Under random mating and ideal conditions, homozygotes have expected frequencies p² and q² and heterozygotes 2pq; these genotype frequencies sum to one.

Q33. What is the formation of new species from existing species called?

[MP Forest Guard/Jail Prahari, 5 June 2023, Shift 3]

(A) Differentiation

(B) Speciation

(D) Regeneration

Answer: (B) Speciation

Explanation: Speciation is the evolutionary divergence through which populations become distinct species. Reproductive isolation often restricts gene exchange, allowing genetic differences to accumulate. Geographic separation is one possible mechanism, but speciation may also occur without a physical barrier.

Q32. Which option is NOT among the five standard factors that disturb Hardy–Weinberg equilibrium?

[MP Excise Constable, 22 February 2023, Shift 2]

(A) Genetic drift

(B) Genetic recombination

(D) Epigenetics

Answer: (D) Epigenetics

Explanation: The textbook list includes mutation, recombination, natural selection, gene migration and genetic drift. These processes can alter allele or genotype distributions. Epigenetics concerns potentially heritable changes in gene regulation and is not separately listed among those five classical Hardy–Weinberg factors.

Q31. Who suggested that life could originate from comparatively simple inorganic substances?

[RRB Group D, 1 September 2022, Shift 3]

(A) Stanley L. Miller

(B) Gregor Mendel

(D) J. B. S. Haldane

Answer: (D) J. B. S. Haldane

Explanation: Haldane and Oparin separately advanced chemical explanations for life’s origin. They proposed that organic precursors could form abiotically before the first biological systems emerged. The later Miller–Urey apparatus tested aspects of this idea without directly creating living organisms.

Q30. Which statement about evolutionary evidence is false?

[NEET UG, 17 July 2022]

(A) Penguin and dolphin flippers are homologous organs

(B) Analogous structures can result from convergent evolution

(D) Homology indicates common ancestry

Answer: (A) Penguin and dolphin flippers are homologous organs

Explanation: Penguin and dolphin swimming flippers perform a similar function but evolved in different vertebrate lineages with distinct modifications. The examination classifies them as analogous. Homology, in contrast, points to a shared underlying ancestral structure despite possible differences in function.

Q29. Which plant was used by Hugo de Vries to develop his mutation theory?

[CUET Biology, 23 August 2022]

(A) Snapdragon

(B) Evening primrose

(D) Garden pea

Answer: (B) Evening primrose

Explanation: De Vries studied evening primrose, Oenothera lamarckiana, and interpreted abruptly appearing inherited forms as evidence for mutation-driven evolutionary change. His historical theory emphasised sudden changes, whereas modern evolutionary biology also recognises gradual population shifts involving selection and genetic drift.

Q28. Whose principle states that allele frequencies in a population remain constant under ideal conditions?

[RSMSSB Laboratory Assistant, 29 June 2022, Paper II]

(A) Sewall Wright

(B) Hardy and Weinberg

(D) Jean-Baptiste Lamarck

Answer: (B) Hardy and Weinberg

Explanation: The Hardy–Weinberg equilibrium gives a null expectation for allele frequencies when mating is random and evolutionary forces are absent. Differences from its assumptions can indicate mutation, migration, selection, drift or nonrandom mating. It is a cornerstone of population-genetic analysis.

Q27. Match the geological heritage sites to their locations:
(a) National Fossil Wood Park,
(b) Shivalik Park,
(c) Stromatolite Park,
(d) Lonar Lake;

(i) Buldhana,
(ii) Chittaurgarh,
(iii) Tiruchirappalli,
(iv) Sirmaur.

[CGPSC 2021 State Services Prelims, 13 February 2022]

(A) (a)–(i), (b)–(ii), (c)–(iii), (d)–(iv)

(B) (a)–(iv), (b)–(iii), (c)–(ii), (d)–(i)

(D) (a)–(iii), (b)–(ii), (c)–(iv), (d)–(i)

Answer: (C) (a)–(iii), (b)–(iv), (c)–(ii), (d)–(i)

Explanation: Fossil Wood Park is at Tiruchirappalli in Tamil Nadu; Shivalik Fossil Park is in Sirmaur, Himachal Pradesh; Stromatolite Park is at Chittaurgarh, Rajasthan; and Lonar Lake lies in Buldhana, Maharashtra. Fossils and stromatolites preserve evidence crucial to studying ancient life.

Q26. Who proposed the mutation theory of evolution?

[DSSSB PGT Biology (Female), 16 July 2021, Shift 1]

(A) Hugo de Vries

(B) Jean-Baptiste Lamarck

(D) Gregor Mendel

Answer: (A) Hugo de Vries

Explanation: Hugo de Vries argued that abrupt inherited changes could create new biological forms, drawing on observations of evening primrose. The idea highlighted mutation as a source of variation. Modern theory combines mutations with natural selection, recombination, gene flow and chance effects.

Q25. Which factor is considered most important for the formation of reproductively distinct species?

[DSSSB PGT Biology (Female), 16 July 2021, Shift 1]

(A) Geographical isolation

(B) Reproductive isolation

(D) Ecological isolation alone

Answer: (B) Reproductive isolation

Explanation: Species remain distinct when effective gene exchange is prevented between their populations. Reproductive isolation can arise through geographical, behavioural, genetic or other barriers. Geographic separation is common but not necessary in every instance of speciation.

Q24. Which process causes the founder effect in a population?

[NEET UG, 12 September 2021]

(A) Genetic drift

(B) Natural selection

(D) Mutation

Answer: (A) Genetic drift

Explanation: The founder effect occurs when a small number of individuals establish a new population. Their allele frequencies may differ by chance from those of the original group. This sampling effect is a form of genetic drift and is strongest in small populations.

Q23. Which statement concerning evolutionary organs is true?

[UPPSC GIC Lecturer Biology, 2021]

(A) Horse forelimbs and whale flippers are analogous

(B) Analogous organs by themselves do not establish close kinship

(D) Insect and bird wings are homologous as wings

Answer: (B) Analogous organs by themselves do not establish close kinship

Explanation: Analogous organs have independently evolved similar functions and therefore do not, merely by being similar, demonstrate close ancestry. Homologous structures share an ancestral anatomical pattern; the vertebrate forelimb is a classic example of such evolutionary kinship.

Q22. In which year was Darwin’s On the Origin of Species published?

[RPSC Assistant Professor (College Education), held 4 October 2021]

(A) 1847

(B) 1851

(D) 1859

Answer: (D) 1859

Explanation: On the Origin of Species was published on 24 November 1859. Darwin had spent many years gathering evidence from biogeography, domestication and comparative biology. The publication provided a major framework for understanding evolutionary diversification through natural selection.

Q21. Evolution of multiple species from a common point of origin into differing habitats is called what?

[SSC CPO, 24 November 2020, Shift 2]

(A) Adjustive radiation

(B) Adaptive radiation

(D) Adjustive evolution

Answer: (B) Adaptive radiation

Explanation: Adaptive radiation is diversification from a common ancestral lineage as descendants exploit different ecological opportunities. Darwin’s finches are a familiar example: varying food sources favoured different beak forms. It is a particular pattern of divergent evolution.

Q20. The flippers of penguins and dolphins illustrate which process?

[NEET UG, 13 September 2020]

(A) Industrial melanism

(B) Natural selection alone

(D) Convergent evolution

Answer: (D) Convergent evolution

Explanation: Penguins are birds, while dolphins are mammals; both independently acquired streamlined swimming appendages. Their similarity in function is an example of convergent evolution. It does not mean the two lineages inherited identical flipper modifications from an immediate common ancestor.

Q19. Who challenged Haeckel’s interpretation of embryological evidence for evolution?

[NEET UG, 13 September 2020]

(A) Charles Darwin

(B) Alexander Oparin

(D) Alfred Russel Wallace

Answer: (C) Karl Ernst von Baer

Explanation: Von Baer criticised the claim that embryos of higher animals pass through adult stages of supposedly lower animals. His embryological laws instead describe development from general towards specialised characteristics. Comparative embryology still offers evolutionary evidence without accepting Haeckel’s strict recapitulation claim.

Q18. Match: 1. De Vries; 2. Pasteur; 3. Darwin; 4. Fox,

with a. Special creation; b. Swan-neck flask; c. Protobiosis; d. Origin of Species; e. Mutation theory.

[RPSC Senior Teacher Grade II (Science), 4 July 2019]

(A) 1–e, 2–a, 3–b, 4–d

(B) 1–a, 2–b, 3–d, 4–c

(D) 1–a, 2–c, 3–d, 4–b

Answer: (C) 1–e, 2–b, 3–d, 4–c

Explanation: De Vries developed mutation theory, Pasteur used swan-neck flasks to dispute spontaneous generation in present-day conditions, and Darwin wrote Origin of Species. Sidney Fox investigated proteinoid microspheres as laboratory models relevant to early prebiotic systems.

Q17. Approximately when did life begin in Earth’s oceans according to the textbook estimate?

[SSC GD Constable, 21 February 2019, Shift 3]

(A) 1 billion years ago

(B) 100 million years ago

(D) 3.5 billion years ago

Answer: (D) 3.5 billion years ago

Explanation: The exam used an estimate of about 3.5 billion years for the earliest oceanic life. Very ancient microbial evidence supports life existing billions of years before animals arose. Precise dating and interpretation remain active research topics, but life clearly predates the Cambrian.

Q16. Non-avian dinosaurs became extinct approximately 65–66 million years ago at the end of which period?

[SSC Junior Engineer (Civil), 23 September 2019, Morning]

(A) Jurassic

(B) Permian

(D) Cretaceous

Answer: (D) Cretaceous

Explanation: The Cretaceous–Palaeogene boundary marks the extinction of non-avian dinosaurs about 66 million years ago. A major asteroid impact is strongly implicated. Birds are surviving dinosaur descendants, so saying every dinosaur vanished would not be scientifically accurate.

Q15. What form of speciation occurs when a species becomes divided into geographically isolated groups?

[Allahabad High Court Review Officer, 2019]

(A) Allopatric

(B) Peripatric

(D) Sympatric

Answer: (A) Allopatric

Explanation: Allopatric speciation starts when a geographical barrier limits gene flow between populations. Mutations, selection and genetic drift can then produce divergence. If reproductive incompatibilities develop, the separated groups may remain distinct even after geographical contact is restored.

Q14. What are organs with different anatomical origins but similar appearances and functions termed?

[RRB Group D, 16 October 2018, Shift 3]

(A) Fossils

(B) Homologous organs

(D) Biogenetic law

Answer: (C) Analogous organs

Explanation: Analogous organs evolve independently to perform comparable tasks. Bird and insect wings, for example, share flight function but differ in anatomy and evolutionary origin. By contrast, homologous organs preserve a common structural pattern inherited from a shared ancestor.

Q13. Which term in the Hardy–Weinberg equation denotes the expected frequency of heterozygotes?

[DSSSB TGT Natural Science (Female), 27 September 2018, Shift 2]

(A) 2qp²

(B) q²

(D) p²

Answer: (C) 2pq

Explanation: For a diploid population with two alleles of frequencies p and q, the expected heterozygous fraction under Hardy–Weinberg assumptions is 2pq. The corresponding frequencies of the two homozygous genotypes are p² and q².

Q12. With which subject is the Miller–Urey experiment principally associated?

[DSSSB TGT Natural Science (Male), 29 September 2018, Shift 2]

(A) Taxonomy

(B) Genetics

(D) Evolution and the origin of life

Answer: (D) Evolution and the origin of life

Explanation: Miller and Urey modelled chemical reactions under assumed primitive atmospheric conditions. Electrical discharges in a gas-and-water apparatus produced organic compounds including amino acids. This provided experimental support for a stage of chemical evolution, not proof that complete living cells were produced.

Q11. Match: I. Charles Darwin; II. Gregor Mendel; III. J. B. S. Haldane

with 1. Origin of life hypothesis; 2. Theory of evolution; 3. Laws of inheritance.

[SSC CHSL, 13 March 2018, Shift 3]

(A) I–2, II–3, III–1

(B) I–1, II–3, III–2

(D) I–3, II–2, III–1

Answer: (A) I–2, II–3, III–1

Explanation: Darwin formulated evolution by natural selection, Mendel derived rules for inheritance from pea-plant crosses, and Haldane proposed a chemical explanation of life’s beginnings. Their contributions addressed different but complementary problems of evolutionary biology and heredity.

Q10. Who proposed the theory of inheritance of acquired characteristics?

[UP LT Grade Teacher (Biology), 2018]

(A) August Weismann

(B) Jean-Baptiste Lamarck

(D) Charles Darwin

Answer: (B) Jean-Baptiste Lamarck

Explanation: Lamarck argued that characters acquired through use, disuse or need could be transmitted to descendants. Weismann later emphasised germ-line continuity, while modern genetics distinguishes changes to body tissues from inherited DNA differences. Darwin developed a separate natural-selection mechanism.

Q9. Studies of human evolution indicate that modern humans originated on which continent?

[RRB ALP CBT I, 31 August 2018, Shift 2]

(A) Western Asia

(B) America

(D) Africa

Answer: (D) Africa

Explanation: Genetic studies and early Homo sapiens fossils support an African origin of our species. Modern humans later dispersed across the world and interbred with some archaic human groups. The exact pattern and timing of these dispersals continue to be refined by evidence.

Q8. Which geological era is widely called the Age of Reptiles?

[UPPSC GIC Lecturer Zoology, 2017]

(A) Palaeozoic

(B) Carboniferous

(D) Mesozoic

Answer: (D) Mesozoic

Explanation: The Mesozoic Era, spanning approximately 252 to 66 million years ago, saw major diversification and terrestrial dominance of reptiles, especially dinosaurs. It comprises the Triassic, Jurassic and Cretaceous periods. Numerous modern animal lineages also trace their origins to this interval.

Q7. Which writer of An Essay on the Principle of Population strongly influenced both Darwin and Wallace?

[WBCS Preliminary Examination, 2016]

(A) Erasmus Darwin

(B) Thomas Robert Malthus

(D) Jean-Baptiste Lamarck

Answer: (B) Thomas Robert Malthus

Explanation: Thomas Malthus argued that populations can increase faster than available food supplies. Darwin and Wallace recognised the implication: more offspring exist than can survive, creating competition. Heritable differences affecting reproductive success can therefore accumulate through natural selection.

Q6. Which of the listed ancient hominids belongs to Homo sapiens?

[RRB NTPC Tier I, 2 April 2016, Shift 2]

(A) D (Proconsuls)

(B) B (Cro-Magnon)

(D) A (Homo ergaster)

Answer: (B) B (Cro-Magnon)

Explanation: Cro-Magnon refers to early anatomically modern humans of Europe and is included within Homo sapiens. Neanderthals and Homo ergaster represent separate archaic human lineages or taxa, while Proconsul was an early ape, not a member of modern humanity.

Q5. Who is principally associated with the evolutionary theory of natural selection?

[WBCS Preliminary Examination, 2015]

(A) Gregor Mendel

(B) Charles Darwin

(D) None of these

Answer: (B) Charles Darwin

Explanation: Charles Darwin developed natural selection as a major explanation of how favourable inherited traits become more common. Alfred Russel Wallace independently proposed a similar mechanism. Mendel contributed inheritance laws, while Morgan’s experiments later linked heredity to chromosomes.

Q4. Who experimentally demonstrated that organic compounds relevant to life could form under simulated primitive conditions?

[UP TGT Biology, 2013]

(A) Alexander Oparin

(B) Thomas Huxley

(D) J. B. S. Haldane

Answer: (C) Stanley Miller

Explanation: Stanley Miller’s 1953 experiment, conducted with Harold Urey, exposed a mixture of simple gases and water vapour to electrical sparks. Amino acids appeared among the products. This showed that prebiotic organic synthesis was plausible, not that life itself had been created.

Q3. Which sequence correctly orders these animal groups by evolutionary appearance?

[UPSC Civil Services Preliminary Examination, 2010]

(A) Otter – Tortoise – Shark

(B) Shark – Tortoise – Otter

(D) Shark – Otter – Tortoise

Answer: (B) Shark – Tortoise – Otter

Explanation: Cartilaginous fishes have a much older evolutionary record than turtles, while otters belong to a relatively recent mammalian lineage. The broad progression is therefore shark, tortoise, otter. Such sequences refer to historical emergence, not direct descent between the living species.

Q2. In traditional evolutionary explanations, loss of limbs in snakes is attributed to which phenomenon?

[UPSC Civil Services Preliminary Examination, 2002]

(A) Use and disuse of organs

(B) Adaptation specifically to burrowing

(D) Inheritance of acquired characteristics

Answer: (A) Use and disuse of organs

Explanation: The question invokes Lamarck’s historical principle of use and disuse, in which unused structures supposedly diminish over generations. Modern evolutionary studies instead explain limb reduction through inherited developmental changes and selection in snake ancestors. The answer reflects the paper’s classical-theory framing.

Q1. Which animal was identified as a connecting link between reptiles and mammals?

[WBCS Preliminary Examination, 2002]

(A) Peripatus

(B) Lungfish

(D) Archaeopteryx

Answer: (C) Duck-billed platypus

Explanation: The platypus is an egg-laying mammal, displaying mammalian traits such as hair and milk production alongside an ancestral egg-laying mode. It is often used in textbooks to illustrate transitional characteristics. Archaeopteryx, in contrast, is a bird-lineage transitional fossil.