If brian has a son who is color-blind, what is known about the genotype of the son's mother?
a. she must have at least one allele for color blindness.
b. she must have two alleles for color blindness.
c. she cannot be homozygous recessive for the gene for color blindness.
d. she cannot be a heterozygous carrier of the gene for color blindness.

The correct answer is option A.  The genotype is defined as a set of genes in our DNA which are responsible for a particular trait. Two organisms that are carbon copy of each other, but if they have the slightest difference, that is because of different genotypes.

If Brian has a son who is color-blind, what is known about the genotype of the son's mother?

A. She must have at least one allele for color blindness.

i think its c. amphipod