Question

A mutagen is

a living thing that has undergone a mutation.

an agent that causes a mutation in DNA.

a mutation that has affected one gene.

a chemical that can poison living cells.

Answer 1

B. or an agent that causes a mutation in DNA.

Step-by-step explanation:

Answer 2

Answer: The correct answer is-

an agent that causes a mutation in DNA.

Mutagen is an agent or a substance that causes permanent change in the genetic material of living organisms ( DNA, deoxyribonucleic acid). This process is called mutation.

A mutagen can be a chemical, physical or biological agent that causes mutation in the DNA.

Example- Physical agents such as -

• Ionizing radiations like alpha particles, gamma rays, X-rays that brings break in the DNA and cause other damages.

• Ultraviolet radiations that creates pyrimidine dimers ( T=T) and causes replication errors if damage is not repaired.