Question

this passage describes the scale type trait in common carp:
carp are large freshwater fish that are often raised for food. before a carp is cooked, its scales are usually removed. normally, carp are covered in small scales arranged in straight rows. but carp with mirror scales have large scales arranged in scattered patches. because mirror scales do not cover the fish’s entire body, carp with mirror scales are easier to prepare for cooking.
in a group of common carp, some individuals have normal scales and others have mirror scales. in this group, the gene for the scale type trait has two alleles. the allele a is for normal scales, and the allele a is for mirror scales.
a certain common carp from this group has mirror scales. this carp has two alleles for mirror scales.
based on this information, what is this common carp’s phenotype for the scale type trait?

Explanation:

The passage states that the common carp in the group with mirror scales has the allele combination "aa" for the scale trait, and the allele "a" is for mirror scales. The phenotype is the observable trait. So we identify the observable scale type from the given info about the allele (a for mirror scales) and the carp's alleles (aa).

Answer:

Mirror scales