Which term describes the position of a gene on a chromosome?
 A:centromere
 B:genotype
 C:locus
 D:phenotype
 A man who is red-green color-blind marries a woman who is neither color-blind nor a carrier for this trait. Which statement would best describe their probable offspring?
 A:All of their sons would be color-blind.
 B:All of their children would be color-blind.
 C:50 percent of their sons would be color-blind.
 D:None of their children would be color-blind but all of their daughters would be carriers.