Environmental factors typically activate genes in a cell by causing the cell to transcribe specific DNA segments to mRNA for translation.
This interaction is an example of environmental factors affecting <u><em>genetic expression</em></u>. In these situations, the environment causes specific segments of DNA to be expressed, meaning they are transcribed to mRNA and subsequently used to form proteins.
Meanwhile, other parts of the genome remain or are forced to be silent. This can be a result of mutations or simple biochemical reactions between the environment and the genome.
