Cancer

Question 1

1. A tumor is
   a. a malignant growth.
   b. any abnormal growth of cells.
   c. a benign growth.
   d. a cancerous growth.
   e. a carcinoma.

Answer 1

b. any abnormal growth of cells.

Question 2

2. A tumor of an epithelial cell is a(n)
   a. carcinoma.
   b. sarcoma.
   c. leukemia.
   d. lymphoma.
   e. adenoma

Answer 2

a. carcinoma.

Question 3

3. The most lethal form of cancer in the United States is _______ cancer.
   a. breast
   b. prostate
   c. lung
   d. colon
   e. skin

Answer 3

c. lung

Question 4

4. 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.
   e. carcinogenic chemicals

Answer 4

c. the stepwise breakdown of normal cell regulatory processes.

Question 5

5. 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.
   e. older people are unable to mount an immune response against cancer cells

Answer 5

d. cancer develops as a consequence of multiple abnormalities that accumulate over many
years.

Question 6

6. 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.
   e. All cells in a tumor from a male express the Y chromosome genes

Answer 6

c. All cells in one tumor from a female have the same X chromosome inactivated.

Question 7

7. Tumor initiation occurs in a
   a. single protein molecule.
   b. single cell.
   c. few cells.
   d. single tissue.
   e. single organ.

Answer 7

b. single cell.

Question 8

8. 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.
   e. inhibits apoptosis

Answer 8

d. causes mutations in DNA.

Question 9

9. 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.
   e. blocks apoptosis.

Answer 9

d. acts as a tumor promoter by stimulating cell proliferation.

Question 10

10. 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
    e. Being exposed to the sun ten minutes per day

Answer 10

b. Smoking a pack of cigarettes a day

Question 11

11. Which of the following is a common difference between normal cells and cancer
    cells?
    a. Density-dependent inhibition of proliferation
    b. Contact inhibition of migration
    c. Growth factor requirements
    d. Cell adhesion
    e. All of the above

Answer 11

e. All of the above

Question 12

12. 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
    e. None of the above

Answer 12

d. All of the above

Question 13

13. 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.
    e. DNA strand breaks

Answer 13

d. DNA replication.

Question 14

14. Oncogenes were first discovered in
    a. a chicken retrovirus.
    b. a human DNA virus.
    c. mouse cancer cells.
    d. human cancer cells.
    e. a human retrovirus

Answer 14

a. a chicken retrovirus.

Question 15

15. The RNA viruses that most commonly pick up cellular oncogenes are the
    a. adenoviruses.
    b. retroviruses.
    c. papilloma viruses.
    d. HIV viruses.
    e. hepatitis C viruses.

Answer 15

d. HIV viruses.

Question 16

31. The tumor suppressor genes Smad2 and Smad4 encode
    a. growth factor receptors.
    b. GTP-binding signal molecules.
    c. transcription factors.
    d. inhibitors that bind to transcription factors.
    e. enzymes that inhibit cell proliferation.

Answer 16

c. transcription factors.

Question 17

32. The normal function of the tumor suppressor protein Rb is to
    a. induce apoptosis.
    b. inhibit Ras.
    c. inhibit progression through the G1 restriction point.
    d. inhibit Cdk4/cyclin B activity.
    e. inhibit c-Myc.

Answer 17

c. inhibit progression through the G1 restriction point.

Question 18

33. An increase in p53 activity usually results after a cell receives
    a. extracellular growth inhibitory signals.
    b. DNA damage.
    c. heat shock.
    d. extracellular growth stimulating signals.
    e. All of the above

Answer 18

b. DNA damage.

Question 19

35. Cancer cells often develop the ability to avoid apoptosis by
    a. surviving in the absence of growth factors.
    b. inactivating p53.
    c. losing the ability to detect DNA damage.
    d. All of the above
    e. None of the above

Answer 19

e. None of the above

Question 20

36. Apoptosis is induced by p53 when
    a. a cell is programmed to die during development.
    b. growth factor levels decline to zero.
    c. any DNA damage is detected.
    d. severe DNA damage is detected and cannot be repaired.
    e. Both a and b

Answer 20

c. any DNA damage is detected.

Question 21

37. The function of the tumor suppressor protein p53 is to
    a. activate the synthesis of p21, a Cdk inhibitor.
    b. induce apoptosis.
    c. phosphorylate cyclin-dependent kinases on an inhibitory site.
    d. All of the above
    e. Both a and b

Answer 21

e. Both a and b

Question 22

43. Angiogenesis inhibitors are useful for inhibiting tumor growth because
    a. blood vessel endothelial cell tumors are common.
    b. inhibiting angiogenesis prevents growing tumors from developing a blood supply,
    thereby starving tumor cells.
    c. they selectively block proliferation of tumor cells.
    d. they destroy existing blood vessels that have grown into tumors.
    e. All of the above

Answer 22

d. they destroy existing blood vessels that have grown into tumors.

Question 23

1. The difference between a benign and a malignant tumor is that a
   a. malignant tumor is painful and a benign tumor is not.
   b. malignant tumor has the ability to spread to other tissues and to initiate tumors at
   secondary sites, whereas a benign tumor does not spread.
   c. benign tumor will cause a less severe form of cancer than a malignant tumor.
   d. malignant tumor is caused by a virus, whereas a benign tumor arises spontaneously

Answer 23

b. malignant tumor has the ability to spread to other tissues and to initiate tumors at
secondary sites, whereas a benign tumor does not spread.

Question 24

2. Which of the following statements about cancers is false?
   a. Carcinomas are malignancies of epithelial cells.
   b. Leukemias are malignancies that arise from blood-forming cells.
   c. Lymphomas are malignancies from colon tissue.
   d. Sarcomas are malignancies of connective tissue such as muscle and bone

Answer 24

c. Lymphomas are malignancies from colon tissue.

Question 25

3. The most lethal type of cancer in the United States is _______ cancer.
   a. prostate
   b. colon/rectum
   c. breast
   d. lung

Answer 25

d. lung

Question 26

4. Which of the following has not been found to cause cancer?
   a. Chemicals
   b. Radiation
   c. Bacteria
   d. Viruses

Answer 26

c. Bacteria

Question 27

6. Angiogenesis contributes to cancer development by
   a. providing nutrients and oxygen to tumors, and by facilitating metastasis.
   b. initiating a mutation in a gene that causes uncontrolled cell growth.
   c. inhibiting apoptosis (programmed cell death).
   d. preventing the normal inhibition of growth that occurs between cells upon contact

Answer 27

a. providing nutrients and oxygen to tumors, and by facilitating metastasis.

Question 28

11. The majority of oncogene proteins are
    a. metabolic enzymes.
    b. structural proteins, such as nuclear lamins.
    c. proteins involved in cell sorting.
    d. components of signaling pathways that regulate cell proliferation

Answer 28

d. components of signaling pathways that regulate cell proliferation