Final answer:
The genotypes possible for the mother of a color-blind man are carrier of the trait (XcX) or non-carrier with normal vision (XX), with the former being more likely as her son is color-blind.
Step-by-step explanation:
The genotypes possible for the mother of a color-blind man indicate that she could be either a carrier of the colorblindness allele or she could have both X chromosomes with the normal vision allele. Since color blindness is an X-linked recessive trait, a color-blind man must have inherited a colorblindness allele (Xc) from his mother because his Y chromosome comes from his father who cannot pass on an X-linked trait. Therefore, the mother's genotype could be heterozygous (XcX) where she is a carrier of the trait but does not express it, or homozygous dominant (XX) for normal vision if she had a chance mutation or inheritance from her own parents. However, since her son is color-blind, it is most likely that she is a carrier (XcX).