Punnett Square
1. In peas, yellow is dominant to green. If a plant
with green seeds is crossed with a heterozygous
yellow seeded plant, what is the probability of
producing a green seeded plant in the offspring?
2. In cattle, red and white hair are co-dominant
alleles. When the two combine, the coat color is
called roan. If a red cow is crossed with a roan
bull, what is the probability of producing a
purebred red calf?
3. In humans, a hitch hikers thumb is dominant to a
straight thumb. If a man with a straight thumb and
a woman heterozygous for a hitchhikers thumb
reproduce, what will the genotypic ratio of the
offspring be?
4. Dihybrid Cross- In plants, being tall is dominant to
short and axial flowers are dominant to terminal
flowers. If a plant heterozygous for both traits
reproduces with a plant that is homozygous tall
with terminal flowers, what are the different
phenotypes that will be produced and the
probability of each.
5. In seals long whiskers are dominant to short. If a
seal heterozygous for long whiskers produces a
seal with short whiskers, what must the genotype
of the other parent seal have been?