How do mutations affect protein function?

Mutations can significantly influence protein function and expression, which is why the choice indicating that mutations may lead to altered protein function or expression is the correct one. When a mutation occurs in the DNA sequence that codes for a protein, it can potentially change the amino acid sequence of the protein. This alteration can in turn affect how the protein folds, its stability, and its overall functionality.

For example, a mutation might create a non-functional protein if the change disrupts critical areas necessary for its activity. Conversely, some mutations might enhance a protein's function or allow it to perform a new function altogether. Additionally, mutations can influence the expression levels of a protein, perhaps increasing or decreasing how much of the protein is made.

Understanding that mutations can lead to various outcomes helps clarify the complexity of genetic variations and their implications in biological processes, including diseases and evolution.