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
(C) A reducing mixture including methane and ammonia
(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
(C) Homology and convergent 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
(C) Origin of the first living molecule
(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
(C) p dominant allele frequency and q recessive 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
(C) It denied environmental changes
(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
(C) They had evolutionary ancestry in common
(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
(C) 1861
(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
(C) Andhra 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
(C) Hydra
(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
(C) Population
(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.
