Question

in a punnett square, what does an uppercase letter represent?
a significant mutation
recessive alleles only
dominant alleles only

Explanation:

In genetics, when using a Punnett square to represent alleles, uppercase letters are used to denote dominant alleles. Recessive alleles are represented by lowercase letters. A "significant mutation" is not what an uppercase letter in a Punnett square represents, and recessive alleles are lowercase, so the correct option is the one about dominant alleles only.

Answer:

dominant alleles only