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
(C) Taxonomic classification
(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.
Q59. Which criterion best establishes common ancestry and evolutionary relationships between closely related species?
[RRB Group D, 11 August 2026, Shift 3]
(A) Activity patterns
(B) Feeding habits
(C) External appearance alone
(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
(C) A–invertebrates, B–extinction, C–seaweeds/plants, D–jawless fish
(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
(C) It increases genetic variation in the population
(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
(C) Absence of evolution
(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
(C) Offspring are identical clones
(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
(C) Some individuals may survive due to favourable differences
(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
(C) Production of genetically identical offspring
(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
(C) Barbara McClintock
(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
(C) It makes human physiology unnecessary
(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.