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
(C) Galápagos tortoise
(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
(C) Palaeontology
(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
(C) A–IV, B–III, C–I, D–II
(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
(C) Palaeoecology
(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
(C) Robert Brown
(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
(C) Water vapour
(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
(C) p² + pq + q² = ∞
(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
(C) Degeneration
(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
(C) Gene flow
(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
(C) Charles Darwin
(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.
