Download Group 2: Question 5, 6, & 7

Group 2: Question 5, 6, & 7
Vanessa Cooper, Michael Crawley, Eric Hoffmann, & Lisa Lee
5) A man with type A blood marries a woman with type B blood. Their child has type O
blood. What are the genotypes of these individuals? What other genotypes, and in what
frequencies, would you expect in offspring from this marriage?
Mother: Ao
Farther: Bo
Child: O
B
o
A
AB
Ao
o
Bo
oo
6) Phenylketonuria (PKU) is an inherited disease caused by a recessive allele. If a woman
and her husband, who are both carriers, have three children, what is the probability of
each of the following?
a. All three children are of normal phenotype.
b. One or more of the three children have the disease.
c. All three children have the disease.
d. At least one child is phenotypically normal.
P stands for normal allele.
k stands for recessive allele with disease.
P
k
a.
b.
c.
d.
P
PP
Pk
k
Pk
kk
1/3
1/4
1/4
1/6
7) The genotype of F1 individuals in a tetrahybrid cross is AaBbCcDd. Assuming
independent assortment of these four genes, what are the probabilities that F2 offspring
will have the following genotypes?
a. aabbccdd
1/4*1/4*1/4*1/4=1/256
b. AaBbCcDd
2/4*2/4*2/4*2/4=1/16
c. AABBCCDD
1/4*1/4*1/4*1/4=1/256
d. AaBBccDd
2/4*2/4*2/4*2/4=1/64
e. AaBBCCdd
2/4*1/4*1/4*1/4=1/128