Question

what is the main reason why genetic variation is necessary for a population?
it prevents any changes from occurring in a population.
it allows a population to adapt to environmental changes.
it guarantees that the environment will remain stable.
it makes all individuals in a population identical

Explanation:

To determine the main reason for the necessity of genetic variation in a population, we analyze each option:

• The first option ("It prevents any changes from occurring in a population") is incorrect because genetic variation is related to providing the raw material for evolution, not preventing change.
• The second option ("It allows a population to adapt to environmental changes") is correct. Genetic variation provides the diversity of traits within a population. When the environment changes, some individuals with favorable traits (due to genetic variation) are more likely to survive and reproduce, allowing the population to adapt over time (through natural selection).
• The third option ("It guarantees that the environment will remain stable") is incorrect. Genetic variation has no direct effect on environmental stability; it is about the population's ability to respond to environmental changes.
• The fourth option (partially visible, but likely suggesting all individuals are identical) is incorrect because genetic variation is the opposite of having identical individuals—variation is the presence of different traits.

Answer:

The Middle Option (It allows a population to adapt to environmental changes)