How does a mutation affect an organism?

A mutation is a change in the DNA sequence of an organism's genome, which can have several effects on the organism. The correct choice highlights that a mutation can change the phenotype of an organism or affect the function of proteins produced by genes. This change can occur in a variety of ways depending on the nature of the mutation—such as a substitution, insertion, or deletion of nucleotides. These alterations can lead to different traits being expressed, or they can modify how proteins operate, which affects the organism's behavior, development, and overall survivability.

Mutations can lead to a range of outcomes, from beneficial changes that give an organism an advantage in its environment to neutral changes that have no significant effect, or even detrimental effects that can lead to health problems. This illustrates the complexity of genetics and how one change at the molecular level can ripple into observable traits and functions at the organism level, resulting in diverse evolutionary pathways.

In summary, the essence of how mutations impact an organism is captured in the choice concerning changes to phenotype or protein function, demonstrating the broad implications of genetic variation.