Mutations that occur in the gametes of an organism will show up where?

The mutation will show up in the organism's offspring.

Explanation: Germ cells are cells that produce reproductive cells called gametes. Germ cells are located only in the gonads and are called oogonia in females and spermatogonia in males. In females, they are found in the ovaries and in males, in the testes. If mutation occurs in the germ cell (i. e., egg or sperm cells) then it is called germinal mutation, this type mutation can be passed to an organism's offspring. As a result of which every cell in the embryo will carry the mutation.

Result: Mutation in gametes are passed to the offspring.