NEET BIOLOGY

Detailed explanation-1: -The chemical or physical agents that cause mutations are called mutagens. Examples of physical mutagens are ultraviolet (UV) and gamma radiation. Radiation exerts its mutagenic effect either directly or by creating free radicals that in turn have mutagenic effects.

Detailed explanation-2: -Ionizing radiation damages the genetic material in reproductive cells and results in mutations that are transmitted from generation to generation.

Detailed explanation-3: -Mutagens cause mutations in three different ways: Some act as base analogs and are mistakenly used as substrates when new DNA is synthesized at the replication fork. Some react directly with DNA, causing structural changes that lead to miscopying of the template strand when the DNA is replicated.

Detailed explanation-4: -Chemical mutagenesis mostly introduces point mutations that can result in amino acid changes in the encoded proteins or premature stop codons leading to truncated proteins.