What is the definition of a mutagen in genetics?

A mutagen in genetics is defined as a physical or chemical agent that alters the genetic material of an organism. This alteration can lead to changes in DNA sequences, which may eventually result in mutations. Mutagens can cause various types of damage to the DNA, including point mutations, insertions, deletions, or more complex rearrangements. Exposure to mutagens can occur through external sources such as radiation (like UV or X-rays) or chemical agents (like certain pollutants or toxins) that interact with the DNA.

Understanding the role of mutagens is crucial because they can contribute to genetic diversity, but they also have implications in cancer and other genetic disorders if the mutations they cause result in harmful changes to the organism's genome. Thus, recognizing the nature of mutagens and their effects is fundamental for anyone studying genetics or working in related fields.