A sudden change in the genetic composition of an organism is termed

A.

mutation

B.

linkage

C.

variation

D.

epistasis

Correct answer is A

Mutation is the process by which there is a permanent alteration in the DNA sequence of an organism's genome. These changes can occur due to various factors such as exposure to radiation, chemicals, or errors during DNA replication. Mutations can happen in somatic cells, which affect only the individual, or in germ cells (egg or sperm cells), which can be passed on to offspring.