What kind of change does a mutagen induce in the DNA?

A mutagen is an agent that causes changes to the DNA sequence, which can alter the genetic code. These changes may occur in various ways, such as substitutions, insertions, or deletions of nucleotides. Such alterations can potentially lead to new traits or affect the function of genes, impacting the overall biological processes within an organism. By inducing a sequence change, a mutagen introduces variations that can be passed on to subsequent generations, emphasizing its role in evolutionary processes.

While structural, coding, or functional changes might be consequences of mutations, the primary action of a mutagen is to change the actual sequence of DNA. This foundational alteration is crucial because it sets the stage for any downstream effects on gene expression and protein synthesis that may occur as a result of the sequence change.