Ch. 19 Flashcards
1
Q
- A tumor is
a. a malignant growth.
b. any abnormal growth of cells.
c. a benign growth.
d. a cancerous growth.
A
b. any abnormal growth of cells.
2
Q
- A tumor of an epithelial cell is a(n)
a. carcinoma.
b. sarcoma.
c. leukemia.
d. lymphoma.
A
a. carcinoma.
3
Q
- The most lethal form of cancer in the United States is _______ cancer.
a. breast
b. prostate
c. lung
d. colon
A
c. lung
4
Q
- Cancer is usually caused by
a. a cancer virus.
b. an inherited oncogene.
c. the stepwise breakdown of normal cell regulatory processes.
d. X rays.
A
c. the stepwise breakdown of normal cell regulatory processes.
5
Q
- The dramatic increase in cancer incidence with age suggests that
a. cancer is caused by old age.
b. genetic factors are not involved.
c. cancer arises primarily in differentiated, nondividing tissues.
d. cancer develops as a consequence of multiple abnormalities that accumulate over many years.
A
d. cancer develops as a consequence of multiple abnormalities that accumulate over many years.
6
Q
- Which of the following is evidence for the single-cell origin of a tumor?
a. All cells in one tumor express the same oncogenes.
b. In a tumor from a female, some cells have one X chromosome inactivated and some have the other X chromosome inactivated.
c. All cells in one tumor from a female have the same X chromosome inactivated.
d. All cells in a tumor express both sex chromosomes, whether they be X or Y.
A
c. All cells in one tumor from a female have the same X chromosome inactivated.
7
Q
- Tumor initiation occurs in a
a. single protein molecule.
b. single cell.
c. few cells.
d. single tissue.
A
b. single cell.
8
Q
- Ultraviolet radiation increases the likelihood of a cell’s becoming malignant primarily because UV radiation
a. induces melanocytes to express more melanin.
b. causes breaks in DNA.
c. makes RNA polymerase more error-prone.
d. causes mutations in DNA.
A
d. causes mutations in DNA.
9
Q
- Estrogen increases the risk of breast and uterine cancers because it
a. inhibits differentiation.
b. causes DNA damage.
c. turns on the BRCA oncogenes.
d. acts as a tumor promoter by stimulating cell proliferation.
A
d. acts as a tumor promoter by stimulating cell proliferation.
10
Q
- Which of the following is most likely to increase the likelihood of contracting cancer?
a. Drinking a glass of wine a day
b. Smoking a pack of cigarettes a day
c. Kissing a person who has cancer
d. Breathing the sawdust from a crown gall tumor
A
b. Smoking a pack of cigarettes a day
11
Q
- Compared to their normal counterparts, leukemic cells
a. fail to differentiate.
b. continue to proliferate.
c. fail to undergo apoptosis.
d. All of the above
A
d. All of the above
12
Q
- The T antigen of SV40 virus binds to DNA and initiates
a. expression of the virus early genes.
b. expression of the virus late genes.
c. proteolytic cleavage of cellular proteins.
d. DNA replication.
A
d. DNA replication.
13
Q
- Oncogenes were first discovered in
a. a chicken retrovirus.
b. a human DNA virus.
c. mouse cancer cells.
d. human cancer cells.
A
a. a chicken retrovirus.
14
Q
- The RNA viruses that most commonly pick up cellular oncogenes are the
a. adenoviruses.
b. retroviruses.
c. papilloma viruses.
d. HIV viruses.
A
d. HIV viruses.
15
Q
- The viral raf oncogene produces a constitutively active protein because the
a. gene is always on.
b. kinase domain is mutant and cannot be competitively inhibited.
c. regulatory domain has been replaced by viral sequences and the protein cannot be turned off.
d. GTPase activity is deficient and the protein is always in the GTP form.
A
d. GTPase activity is deficient and the protein is always in the GTP form.
