Hemophilia is a sex-linked, recessive trait. Which of the following describes the probability of hemophilia in the offspring of a man who does not have hemophilia and a woman whose father is a hemophiliac?

Alleles for the A and B blood cell antigens are codominant. The condition where no antigens are present on the blood cells (type O blood) is a recessive trait. Which set of parents can most likely produce a child with type O blood?

One of the parents of a child has phenylketonuria (PKU), which is caused by recessive alleles. The other parent does not have the PKU alleles. What is the chance that the couple will have a child with phenylketonuria?

Hitchhiker's thumb (H) is dominant to no hitchhiker's thumb (h). A woman who does not have hitchhiker's thumb marries a man who is heterozygous for hitchhiker's thumb. What is the probable genotypic ratio of their children?

What is the genotype of individual 6?

This diagram shows a diploid cell with two pairs of homologous chromosomes.

Due to independent assortment, what is the possible genetic make-up of gametes produced by this organism?

The table lists the trials for fruit color where allele R exhibits incomplete dominance over allele R'.

Heterozygous fruit have orange phenotypes. What percent of offspring are expected to have an orange phenotype if the parent plants are orange (RR') and yellow (R'R')?

Mendel hypothesized that reproductive cells have only one factor for each inherited trait. This hypothesis is supported by which observation?

A human baby boy inherits a recessive allele from his mother. In which circumstance would he most likely show the trait coded for by the recessive allele?

In cattle the allele for cloven hooves (H) is dominant over the allele for mule-foot hooves (h). The phenotype for each trait is shown in this picture.

What is the probability of cloven hooves in the offspring of parents that are heterozygous for the trait?

The four butterflies in the illustrations represent the offspring in the F 1 generation. Which statement is best supported by the phenotypes of these offspring?

Chickens can have different types of feathers. Frizzled feathers curl toward a chicken’s head. Assume that feather type is determined by a single gene and that the allele for frizzled feathers is dominant over the allele for straight feathers. In a cross between two chickens with straight feathers, what percentage of the offspring can be expected to have frizzled feathers?