Student performance on exam questions related to the cancer activity.
Exam Question 1 (This questions targets LO1): The DCC gene has been implicated in
early onset testicular cancer. Below is a pedigree of a family showing the incidence of
early onset testicular cancer with a particular DCC- allele.
DCC+/ DCC- males that have this DCC- allele have a high chance of developing early
onset testicular cancer.
Females do not get testicular cancer.
Individuals II-1 and II-5 are DCC+/DCC+.
There are no DCC-/DCC- individuals in this family.
Which mode of inheritance is most consistent with the information in the pedigree?
A. Autosomal dominant
B. Autosomal recessive
C. X-linked dominant
D. X-linked recessive
E. Y-linked
Answer: A, 87% correct
Exam Question 2. If you isolated DNA from II-4’s cheek cells, you would expect to
find:
A. No DCC sequence
B. Only mutant DCC sequence
C. Only wild-type DCC sequence
D. Both mutant and wild-type DCC sequence
Answer: D, 89% correct
Exam Question 3 (This questions targets LO2): III-3 has a son with Mohammed who
does not have early onset testicular cancer and no family history of the disease. What is
the chance their son will develop early onset testicular cancer if the disease is fully
penetrant?
A. 0%
B. 25%
C. 50%
D. 66.7%
E. 100%
Answer: B, 68% correct
Exam Question 4 (This questions targets LO3): Mutations in p53 are associated with an
aggressive form of breast cancer. Normally the p53 protein stops the cell cycle if DNA is
damaged. Mutations in the p53 gene prevent the production of the p53 protein. Without
a functional p53 protein, cells continue to divide even when there is DNA damage.
The p53 gene is a:
A. Tumor suppressor gene
B. Proto-oncogene
Answer: A, 87% correct