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Evolution — BIOLOGY STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceBIOLOGYEvolution5 Marks
Question
State and explain any three factors affecting allele frequency in populations.
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Answer

Following are the three out of five factors which affect allele frequency in populations:
  1. Genetic Drift: The change in the frequency of a gene variant in a population due to random sampling is called genetic drift. Genetic drift may cause a gene variant to disappear completely and result in reduced genetic variation.
  2. Genetic Recombination: Production of offspring with traits which differ from parents is called genetic recombination.
  3. Natural Selection: This theory is based on the premise that nature selects only those traits which help an organism to survive in the changed conditions. Natural selection leads to survival of the fittest. Those which are not fit to survive perish in the long run; paving the way for evolution of a new species.

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