What is a mutation?

A mutation refers to a change in the DNA sequence of an organism. This alteration can occur in various ways, such as substitutions, deletions, or insertions of nucleotides, and it can have a range of effects on the organism. Some mutations might lead to changes in the protein produced by a gene, potentially affecting the organism's traits, while others might be silent, having no impact on the functionality of the protein or the organism itself.

Understanding mutations is crucial because they are the raw material for evolution. Mutations can introduce new genetic variation into a population, which is then subject to natural selection. This process can lead to the adaptation of species over time.

In contrast to the other options, a harmful environmental change does not accurately capture the concept of a mutation, as mutations are specific alterations within the genetic material rather than external influences. The process of natural selection is a mechanism that acts on existing mutations rather than defining what a mutation is. Finally, cellular respiration is a biochemical process for energy production and is unrelated to the genetic changes that define mutations. Thus, acknowledging that a mutation is fundamentally a change in the DNA sequence clarifies its significance in genetics and evolutionary biology.