Q31. Which of the following is a mechanism of evolution that occurs due to random changes in allele frequencies in a population?
a) Genetic drift
b) Gene flow
c) Natural selection
d) Mutation
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Correct Answer: a) Genetic drift
Explanation: Genetic drift refers to the random fluctuations in allele frequencies within a population due to chance events. It is most pronounced in small populations and can lead to the loss of genetic diversity over time.
Q32. Which evolutionary concept suggests that species evolve rapidly in short bursts followed by long periods of little change?
a) Gradualism
b) Punctuated equilibrium
c) Adaptive radiation
d) Convergent evolution
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Correct Answer: b) Punctuated equilibrium
Explanation: Punctuated equilibrium proposes that evolutionary change occurs in rapid bursts of speciation followed by long periods of stasis, where species remain relatively unchanged. This pattern contrasts with the gradualism model of continuous, slow change.
Q33. What term describes the process by which organisms become better suited to their environment over successive generations?
a) Adaptation
b) Speciation
c) Hybridization
d) Extinction
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Correct Answer: a) Adaptation
Explanation: Adaptation refers to the process by which organisms evolve traits that increase their fitness and survival in a particular environment. These traits are shaped by natural selection and allow organisms to better exploit their ecological niche.
Q34. Which of the following is an example of coevolution?
a) Predator and prey
b) Parasite and host
c) Pollinator and plant
d) All of the above
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Correct Answer: d) All of the above
Explanation: Coevolution occurs when two or more species reciprocally influence each other’s evolution through close ecological interactions. Examples include predator-prey relationships, parasite-host interactions, and mutualistic relationships like pollination.
Q35. What is the term for structures that are inherited from a common ancestor but may have different functions in descendants?
a) Analogous structures
b) Homologous structures
c) Vestigial structures
d) Adaptive structures
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Correct Answer: b) Homologous structures
Explanation: Homologous structures are anatomical features inherited from a common ancestor, but they may have different functions in descendants due to adaptation to different environments or behaviors.
Q36. What mechanism of evolution involves the movement of genes between populations through migration?
a) Genetic drift
b) Gene flow
c) Mutation
d) Natural selection
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Correct Answer: b) Gene flow
Explanation: Gene flow is the exchange of genetic material between populations through the movement of individuals. It introduces new genetic variation into populations and can counteract genetic drift and promote adaptation.
Q37. Which of the following is NOT a condition for natural selection to occur?
a) Variation in traits within a population
b) Differential reproductive success
c) Non-heritability of traits
d) Environmental pressure
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Correct Answer: c) Non-heritability of traits
Explanation: Natural selection requires variation in traits within a population, differential reproductive success associated with those traits, and environmental pressure. Heritability of traits is essential for the transmission of advantageous traits to future generations.
Q38. What term describes the process by which a single species diversifies into multiple species, each adapted to a different ecological niche?
a) Convergent evolution
b) Divergent evolution
c) Adaptive radiation
d) Coevolution
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Correct Answer: c) Adaptive radiation
Explanation: Adaptive radiation occurs when a single ancestral species rapidly diversifies into multiple species, each adapted to different ecological niches or habitats. This often happens when organisms colonize new environments with diverse resources and ecological opportunities.
Q39. Which of the following is an example of vestigial structures in humans?
a) Appendix
b) Lungs
c) Heart
d) Liver
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Correct Answer: a) Appendix
Explanation: Vestigial structures are remnants of ancestral traits that have lost their original function over evolutionary time. The human appendix is considered a vestigial structure, believed to be a reduced remnant of a larger structure in our evolutionary ancestors.
Q40. What type of selection favors individuals with traits at one extreme of the phenotypic range?
a) Stabilizing selection
b) Directional selection
c) Disruptive selection
d) Balancing selection
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Correct Answer: b) Directional selection
Explanation: Directional selection occurs when environmental pressures favor individuals with traits at one extreme of the phenotypic range, leading to a shift in the average phenotype of the population over time.