Download genetic problems II

2107 More Genetics Practice
1) A color-blind man and his wife, with normal vision, have a color-blind daughter. What is the
probability that their newborn son will also be color blind?
2) Hemophilia is a recessive genetic disorder whose disorder allele, which we’ll call a, is located on
the X chromosome. What are the chances that parents with the following genotypes will have a
child with hemophilia?
a. XAXA x XaY
b. XAXa x XaY
c. XAXa x XAY
d. XaXa x XAY
3) Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal
color vision have a color-blind. What are the genotypes of the parents?
4) Cinnabar eyes is a sex-linked recessive characteristic in fruit flies. If a female having cinnabar
eyes is crossed with wild-type make, what percentage of the F1 males will have cinnabar eyes?
5) In humans, male-pattern baldness is controlled by a gene that occurs in two allelic forms. Allele
Hn determines nonbaldness, and allele Hb determines pattern baldness. In males, because of
the presence of testosterone, allele Hb is dominant over Hn. If a man and woman both with
genotype HnHb have a son, what is the chance that he will eventually be bald?