C 5. Compared to X-linked dominant diseases, what is the prevalence of X-linked recessive diseases?
a. Less common
b. Equally common
c. More common
d. Cannot be determined
Q8. Why are women somewhat protected from X-linked disorders?
a. They have two X chromosomes
c. They have more autosomes
b. They have one X and one Y chromosome
d. They lack the gene for X-linked disorders
How many mutant X chromosomes are needed for a female to express X-linked recessive diseases?
a. None
c. Two
b. One
d. Three
C 7. What term is used to describe females who carry the gene for a disorder but do not express the disorder themselves?
a. Expressors
c. Carriers
b. Dominants
d. Affected
a 8. What is the inheritance pattern in X-linked recessive diseases for sons of an affected mother?
a. All sons are affected
b. None of the sons are affected
c. Only the first-born son is affected
d. Sons have a 50% chance of being affected
II. PROBLEM SOLVING. Solve the following multiple alleles and sex-linked trait problems. Set up Punnet squares for each of the crosses given below on a separate sheet of paper.
MULTIPLE ALLELES:
9-13: It was suspected that two babies had been exchanged in a hospital. Mr. and Mrs. Jones received baby #land Mr. and Mrs. Simon received baby #2. Blood typing tests on the parents and the babies showed the following:
Mr. Jones: Type A
Mrs. Jones: Type O
Baby #1: Type A
We Create Possibilities for Lifelong Learning.