Name______________
Genetics Review
Please show all Punnett squares.
1. In pea plants, tall (T) is dominant over short (t). Cross a heterozygous tall plant with
a short one. Show the genotype and phenotype ratios of the offspring.
2. Also in pea plants, purple flowers (P) are dominant over white (p). Cross a
homozygous tall heterozygous purple plant with a heterozygous tall white plant.
Show the genotype and phenotype ratios of the offspring.
3. In snapdragons, red (R) and yellow (Y) flowers are incompletely dominant. Cross a
red plant with a yellow plant. What is the probability of getting a red-flowered
offspring?
4. In shorthorn cattle, red (CR) and white (CW) coat colors are codominant. A
heterozygote is roan-colored. Cross two roan cattle. What is the probability of
getting a roan offspring?
5. In humans, eye color is polygenic. The colors range from dark brown (AABB) to
light blue (aabb). Cross two people with light blue eyes. What is the probability that
they will have a light blue eyed child?
6. Blood types in humans exhibit both codominance and multiple alleles. If a woman
with type A, whose father was type B, marries a man with type O, what are the
chances that their child will also be type O?
7. In humans, colorblindness is a recessive sex-linked trait. If a colorblind woman
marries a normal man, and they have a son, what are the chances that he will be
colorblind?