Why does genetic diversity have a major role in the adaptability and survival of a species?

The correct option is Ability of population to adapt to changing environment.

Genetic diversity refers to the total variety of genetic characteristics within the genetic makeup of a species. It plays a critical role in the long-term survival and adaptability of a population for several key reasons:

1. Variation in Traits: High genetic diversity ensures that individuals within a population possess different combinations of genes and physical traits. When the surrounding environment undergoes changes (such as climate shifts, new diseases, or changes in food supply), some individuals will possess pre-existing genetic variations that enable them to survive under the new conditions.

2. Natural Selection and Adaptation: Individuals with advantageous genetic traits are more likely to survive, reproduce, and pass those favorable traits to their offspring. Over generations, this allows the population as a whole to adapt to changing environmental conditions.

3. Prevention of Extinction: A population with low genetic diversity is highly uniform. If an environmental change or disease occurs that harms one individual, it is likely to affect all individuals equally, significantly increasing the risk of extinction. Genetic diversity acts as a buffer against extinction by ensuring that at least some members can withstand environmental pressures.

Therefore, genetic diversity primarily serves to enhance the ability of a population to adapt to an ever-changing environment.