Question

When populations are small, gene frequencies can change from generation to generation and some alleles may become fixed in a population. This is called ............

• A. Assortative mating
• B. Inbreeding
• C. Heterosis
• D. Genetic drift

Hint:

Genetic drift plays a crucial role in small populations, causing random changes in allele frequencies over time and potentially leading to allele fixation.

Answer 1

The Correct Option is D

Let's analyze each option:
(1) Assortative mating: Assortative mating refers to non-random mating where individuals with similar traits are more likely to mate. It does not explain changes in gene frequencies due to small populations. Hence, this is not the correct answer.
(2) Inbreeding: Inbreeding refers to the mating of closely related individuals, but it does not specifically refer to random changes in allele frequencies or allele fixation in small populations. Hence, this is not the correct answer.
(3) Heterosis: Heterosis, or hybrid vigor, refers to the enhanced traits of hybrid offspring. It does not relate to gene frequency changes due to small population sizes. Hence, this is not the correct answer.
(4) Genetic drift: Genetic drift refers to random fluctuations in allele frequencies in small populations due to chance. It can result in some alleles becoming fixed or lost in the population. This is the correct answer.
Conclusion: The correct answer is Option 4: Genetic drift as it refers to the random change in allele frequencies in small populations.