Download Genetic Worksheet #8

Genetics Worksheet #8
Directions: These are the questions. Show your work on a piece of your notebook paper.
It’s okay to use a pencil.
1. MULTIPLE ALLELES: A woman with blood type B marries a man who has blood
type A. They have 5 children all with type AB blood. What are the most probable
genotypes of the parents? Parental genotypes if their 6th child has type O blood?
2. Suppose that in outer space there exist creatures in which purple eyes, P, are dominant
to yellow eyes, p. Two purple-eyed creatures mate and produce 4 offspring. Three of
them have purple eyes and one has yellow eyes. What are the genotypes of the parents?
What are the genotypes of the offspring?
3. In fruit flies, long-wing, L, is dominant to miniature wing, l. Two long-winged flies
produced 49 miniature winged and 148 long-winged offspring. What are the genotypes
of the parents?
4. The parents of a blue-eyed man were both brown-eyed. He marries a brown-eyed
woman whose father was brown-eyed and whose mother was blue-eyed. They have one
child with blue eyes. What are the genotypes of the people in this problem?
5. A man and his wife are both heterozygous for brown eyes. They have 6 children all
with blue eyes. How is this explained? What are the chances that their next child will
have blue eyes?
6. In Andalusian fowl the gene for black plumage, b, is incompletely dominant to the
gene for white, w. The heterozygous condition, bw, results in blue plumage. List the
phenotypic ratios expected from the following crosses:
(A) black x blue
(B) blue x blue
(C) blue x white
7. In cattle, black coat, B, is dominant to white coat, b. A farmer has a black bull of
undetermined genotype. How can the farmer determine the genotype of the bull?
8. In guinea pigs, black color, B, is dominant to albino, b. Rough coat, R, is dominant to
smooth coat, r. Two animals are selected for breeding. Their genotypes are BBRR and
bbrr. What is the genotype and phenotype of the F 1 generation? In the F 2 generation,
what are the phenotypes: And what are the phenotypes among the offspring produced
from crossing one of the F 1 pigs with a pig having the genotype BBRr?
9. A black, smooth guinea pig was mated with an albino, rough guinea pig. Their
offspring were black rough and black smooth. These were the only types produced over
a period of years in a number of matings. What are the genotypes of the parents?
10. In bulls, black coat, R, is dominant to red coat, r. Hornless, or polled H, is dominant
to horned, h. A certain bull was mated to four cows.
Cow #1
black and hornless, gave birth to a hornless red calf
Cow #2
hornless red, gave birth to a horned black calf
Cow #3
horned black, gave birth to a horned red calf
Cow #4
horned red, gave birth to a hornless black calf
What is the genotype of the bull? What are the genotypes of each of the cows and their
calves?
11. MULTIPLE ALLELES: One parent was type A blood and the other parent was type
B. What are the genotypes if they produced a large number of children whose blood
types were:
a. all AB
b. ½ AB and ½ A
c. ½ AB and B
d. ¼ AB, ¼ A, ¼ B, ¼ O
12. MULTIPLE ALLELES: A woman with blood type B has a child with blood type O.
What are the genotypes of the mother and child? Which genotypes could the father not
have?