List several mutagens that can increase the frequency of mutations

Mutagens can be described as substances which cause mutation. Mutations can be described as any changes in the DNA of an organism.

Mutations can be introduced by chemicals or naturally.

Mutagens which can cause mutations are:

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.