Genetic Drift and Isolation

What is genetic drift?

• The process by which individuals that are better adapted to their environment survive and reproduce more successfully.

• The change in the frequency of an existing gene variant (allele) in a population due to random sampling of organisms.

• The transfer of genes from one population to another.

• The modification of gene expression rather than alteration of the genetic code itself.

Which of the following scenarios is an example of genetic drift?

• A giraffe with a longer neck surviving better and having more offspring.

• A small population of rabbits becoming isolated from their original population and developing different traits over time.

• A bacteria developing resistance to antibiotics and passing this trait to its offspring.

• A flower being pollinated more often because of its bright color.

What is the bottleneck effect?

• The increase in genetic variation following a period of high mutation rates.

• The decrease in a population's size when it expands too quickly.

• The sudden reduction in a population's size due to environmental events.

• The gradual change in species over time to adapt to their environment.

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What is the founder effect?

• The loss of genetic variation when a new colony is established by a very small number of individuals from a larger population.

• The effect of the first species to colonize a new habitat, dominating the ecosystem.

• The phenomenon where the first gene variant to appear in a population rapidly becomes the most common.

• The impact of the initial founding members of a population on the social structure of that population.

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How does genetic drift affect small populations?

• It has a larger effect because each individual represents a larger fraction of the gene pool.

• It has a smaller effect because there are fewer alleles for selection.

• It does not affect small populations, only large ones.

• It increases genetic diversity in small populations.

In which scenario would genetic drift most likely be an important factor?

• In a large population with high gene flow.

• In a small, isolated population.

• In a population undergoing strong natural selection.

• In a population where all individuals have equal fitness.

What role does genetic drift play in evolution?

• It is the primary driver of new species formation.

• It can lead to the fixation or loss of alleles in a population, contributing to genetic variation.

• It prevents populations from adapting to their environment.

• It ensures that only the strongest alleles are passed down to future generations.

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Which of the following factors does NOT influence genetic drift?

• Population size.

• Mutation rate.

• Migration patterns.

• Individual fitness.