Deck 12: Genes and Cancer

Question 1

Which of the following statements about retinoblastoma offers support for the idea that multiple mutations are needed in cancer?

A) Noninherited cases involve both eyes and occur later in life.
B) Noninherited cases involve both eyes and occur early in life.
C) Inherited cases involve one eye and occur early in life.
D) Inherited cases involve one eye and occur late in life.
E) Noninherited cases involve one eye and occur later in life.

Answer 1

E

Question 2

What phrase best describes the field of epidemiology?

A) It is the study of factors that control the presence or absence of disease.
B) It is the study of infectious disease.
C) It is a direct and experimental science.
D) It begins with laboratory studies on experimental animals.
E) It is none of these.

Answer 2

A

Question 3

Which of the following is a characteristic of all cancers?

A) Uncontrolled cell division
B) Metastasis
C) Rapid proliferation
D) Uncontrolled cell division and metastasis only
E) All of these are characterisitic of all cancers

Answer 3

D

Question 4

What is a proto-oncogene?

A) A gene that regulates cell division.
B) A cancer gene.
C) A gene that encodes tumor-suppressing proteins.
D) A DNA repair gene.
E) More than one of these.

Question 5

The percentage of cancers associated with an inherited predisposition is approximately _________.

A) 5 percent
B) 10 percent
C) 15 percent
D) 50 percent
E) 75 percent

Question 6

Which of the following is not a checkpoint in the cell cycle?

A) The G1/S transition
B) The S/G2 transition
C) The G2/M transition
D) Late metaphase
E) The prophase/ metaphase transition

Question 7

Which of the following is NOT a risk factor associated with cancer?

A) Advanced age
B) Smoking cigarettes
C) Family history of cancer
D) Viral infections
E) All of these are risk factors associated with cancer

Question 8

What kind of proteins do the ras proto-oncogenes encode?

A) Signal transduction proteins
B) Tumor-suppressing proteins
C) DNA repair proteins
D) DNA polymerases
E) Mitotic spindle proteins

Question 9

Mutations that convert proto-oncogenes to oncogenes are mutations that cause

A) the gene to produce an altered gene product.
B) underproduction of a normal gene product.
C) overproduction of a normal gene product.
D) an increase in the number of copies of the normal gene.
E) all of these.

Question 10

The drug herceptin (tratuzumab) functions by _____________.

A) blocking signals between the external environment and the nucleus
B) reactivating ras proteins
C) blocking the methylation of histone proteins
D) stimulating the activity of DNA repair genes
E) switching off overactive proto-oncogenes

Question 11

Which of the following best describes the effect of cancer-causing mutations on the cell cycle?

A) The mutations increase the speed of the cycle.
B) The mutations cause the cell to bypass checkpoints in the cycle.
C) The mutations eliminate one or more stages of the cycle.
D) The mutations interfere with S stage of the cycle.
E) None of these.

Question 12

The more cells divide, the more chances for a cancer to develop. Which of the following cells is most likely to give rise to a cancer?

A) Egg cells
B) Muscle cells
C) Nerve cells
D) Mature skin cells
E) Stem cells

Question 13

The pRB protein associated with retinoblastoma, if normal and present,

A) prevents the cell from moving from G1 to S.
B) causes the cell to move from G1 to S.
C) prevents the cell from moving from G2 to M.
D) causes the cell to move from G2 to M.
E) causes the cell to move from S to G2.

Question 14

The discovery of the nature of the Philadelphia chromosome in myelogenous leukemia represents

A) a chromosome aberration that is secondary to the cancer.
B) an aberration that is caused by the development of cancer.
C) a translocation that is a chance event.
D) a specific chromosome aberration accompanying a specific cancer.
E) evidence of exposure to chemical carcinogens.

Question 15

When a cell stops dividing by mitosis, at which stage of the cell cycle does it stop?

A) G1
B) S
C) G2
D) Mitosis
E) Cytokinesis

Question 16

Mutation of the APC gene has been identified as the first step toward development of

A) breast cancer.
B) familial adenomatous polyposis (FAP).
C) hereditary nonpolyposis colon cancer (HNPCC).
D) retinoblastoma.
E) acute myeloblastic leukemia.

Question 17

Hereditary nonpolyposis colon cancers (HNPCC)

A) are caused by mutations in tumor-suppressor genes.
B) are caused by mutations in DNA repair genes.
C) increase mutation rates in microsatellite regions.
D) are caused by mutations in DNA repair genes and increases mutation rates in microsatellite regions.
E) are characterized by all of these traits.

Question 18

In what part of the cell cycle is expression of BRCA1 and BRCA2 genes highest?

A) Mitosis to cytokinesis transition
B) G1/S transition
C) G2/ mitosis transition
D) S/G2 transition
E) Metaphase to anaphase transition

Question 19

Which one of the following statements about the BRCA1 gene for breast cancer is FALSE?

A) It was discovered by Mary-Claire King and her colleagues.
B) The gene is also linked to ovarian cancer.
C) One mutated copy of BRCA1 is sufficient to cause cancer.
D) Although only 1 in 200 females inherit it, 90 percent of them will develop breast cancer.
E) It is located on the long arm of chromosome 17.

Question 20

According to the American Cancer Society, 30 pecent of all cancer deaths is due to

A) ultraviolet light exposure.
B) automobile exhaust.
C) industrial pollutants.
D) pesticide and herbicide exposure.
E) smoking.

Question 21

Products of tumor-suppressor genes act at control points in the cell cycle.

Question 22

The drug Gleevec is most closely associated with which of the following molecules?

A) DNA
B) mRNA
C) ATP
D) NADH
E) tRNA

Question 23

The variability among people in sensitivity to environmental carcinogens is partly genetic.

Question 24

Formation of ____________________ is an intermediate stage in the development of colon cancer.

Question 25

The primary risk factor for cancer is ____________________.

Question 26

The BRCA1 and BRCA2 genes both function in the process of ____________________.

Question 27

The product of the RB tumor-suppressor gene is found in the cytoplasm.

Question 28

____________________ genes normally suppress cell divisions.

Question 29

Specific aneuploidies are associated with various cancers.

Question 30

Some cancers can be considered to be multifactorial since both genes and environment are involved in their expression.

Question 31

All breast cancers result from a recessively inherited gene that suppresses cell division.

Question 32

Mutations of the tumor-suppressor gene ____________________ are pivotal in formation of many cancers.

Question 33

Burkitt's lymphoma, chronic myelogenous leukemia, and many other leukemias are caused by chromosome ____________________.

Question 34

While oncogenes are responsible for cancer cells, tumor-suppressing genes are responsible for tumorous tissues.

Question 35

The older a person is, the more likely he or she will develop cancer.

Question 36

The ras gene is an example of a tumor-suppressing gene.

Question 37

Myelogenous leukemia is caused by a mutant tumor-suppressing gene.

Question 38

Retinoblastoma occurs only in one eye in patients at a low risk of developing other cancers when the ____________________ form is present.

Question 39

Individuals have different ____________________ to environmental agents that cause cancer.

Question 40

The genetic model of colon cancer states that development of colo-rectal cancer requires only one key mutation.

Question 41

It is estimated that 50 percent of all cancer deaths are related to behavior. Knowing the risks (and keeping in mind that you have a one in three chance of having cancer), do you feel inclined to alter your lifestyle to reduce your cancer risk? If so, what steps would you take? If not, why not?

Question 42

If retinoblastoma requires mutation in two copies of the RB gene, and familial cases inherit one such mutation, doesn't it seem unlikely that a second mutation would occur in a retinal cell at this specific gene? Yet 90 percent of those individuals who inherit one mutant RB gene develop a second mutation and retinoblastoma. Why does this occur with such a high frequency?

Question 43

Chronic myelogenous leukemia is an example of a cancer caused by __________________.

Question 44

Epigenetic changes that can lead to cancer development involve changes in patterns of _____________.

Question 45

The anticancer drug Gleevec works by blocking the ____________________-binding site of a protein, which would otherwise activate a signal protein to induce cell division.

Question 46

BRCA1 and BRCA2 are inherited in a ______________ fashion.

Question 47

A cellular molecular pathway by which an external signal is converted into a functional response is called ________________.

Question 48

Targeted drug therapies that stop the growth of cancer cells do so by blocking the action of __________ proteins.

Question 49

Some people have a genetic predisposition to cancer. Explain.

Question 50

How might genetically-engineered human gene products be used to inhibit the action of oncogenes? What type of gene products would you try to develop as anti-oncogene compounds?

Question 51

An autosomal dominant type of colon cancer associated with microsatellite DNA instability is ________________.

Question 52

What is the role of oncogenes and tumor-suppressor genes, and how can mutations in these genes lead to cancer?

Question 53

Scientists now believe that cancer can be caused by both genetic and environmental factors. Describe two environmental factors that may cause cancer regardless of your genetic make-up. What kinds of cancers do these factors usually cause?

Question 54

Most (90 percent) of all cases of ____________________ cancer involve mutations of the MSH2 or MLH1 genes, which destabilize the genome.

Question 55

Discuss what tumor-suppressor genes do and give an example of a disorder where these tumor-suppressor genes may be missing.

Question 56

The products of both the BRCA1 and BRCA2 genes bind to a protein involved in repair of ____________________ (what kind of DNA damage?).