Question

The phenomenon indicated by A is

• A. Outbreeding
• B. Bottleneck effect
• C. Sewall Wright effect and founder effect
• D. Founder effect

Answer 1

Answer: (B)

A population bottleneck is a sharp reduction in the size of a population due to environmental events (such as earthquakes, floods, fires, or droughts) or human activities (such as genocide). Such events can reduce the variation in the gene pool of a population. After an event, a smaller population (of animals/people), with a correspondingly smaller genetic diversity, remains to pass on genes to future generations of offspring. Genetic diversity remains lower, only slowly increasing with time as random mutations occur. Thus, the above phenomenon is called as bottle neck effect. So, option D is correct.
In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. This is not related to the above phenomenon. Thus, option B is wrong.
The intentional breeding of distantly related or unrelated individuals for the purpose of producing offspring of superior quality is called as out breeding. This is not related to the above phenomenon. Thus, option A is wrong.
Genetic drift, also called genetic sampling error or Sewall Wright effect, a change in the gene pool of a small population that takes place strictly by chance. This is not related to the above phenomenon. Thus, option C is wrong.