What do we call a chemical or physical agent that interacts with DNA and causes a mutation?

A mutagen is a chemical or physical agent that interacts with DNA and causes changes or mutations in the genetic material. Mutagens can lead to alterations in the DNA sequence, which may result in various effects ranging from benign variations to severe genetic disorders.

Understanding the context of mutagens is crucial. For example, not all environmental agents that affect living organisms cause mutations; carcinogens are specifically substances that can lead to cancer, but they only do so by causing mutations in certain circumstances and do not encompass all agents that directly alter DNA. Teratogens, on the other hand, are agents that cause malformations in a developing embryo or fetus, typically during pregnancy. Allergens are substances that provoke an allergic reaction and do not interact with DNA to cause mutations.

Thus, the definition of a mutagen is broad and encompasses a variety of agents that can directly lead to changes in DNA, making it the correct term in this context.