Driver mutations provide a growth advantage to a tumor cell. Which type of mutation is known to accumulate in cancer cells but has no direct contribution to the cancer phenotype?
A) alteration mutations
B) passenger mutations
C) carrier mutations
D) indirect mutations
E) insignificant mutations
B
Which of the following three general mechanisms appear to be involved in the conversion of proto-oncogenes to oncogenes?
A) point mutations, translocations, overexpression
B) inversions, translocations, methylation
C) familial, sporadic, phosphorylation
D) transdetermination, mutation, allosteric interactions
E) suppression, tabulation, projection
A
Which protein combines with cyclins to exert local control of the cell cycle?
A) cyclin-dependent kinase
B) phosphatase
C) ATPase
D) integrase
E) hexokinase
A
A protein that functions as a cell-cycle regulator causes cell death (apoptosis) under high sunlight exposure. Which symbol given to this protein?
A) p34
B) p102
C) cyclin
D) p53
E) phosphokinase
D
The retinoblastoma protein (pRB), like p53, serves as a(n) ________ in regulating the cell cycle.
A) tumor suppressor
B) tumor enhancer
C) up regulator
D) oncogene
E) pseudooncogene
A
Mutant versions of genes that are normally involved in promoting the cell cycle are known as ________.
A) tumor suppressors
B) proto-oncogenes
C) oncogenes
D) malignant genes
E) attenuators
C
In sporadic cases of retinoblastoma, how many gene mutations are thought to be necessary in the same cell for a tumor to develop?
A) one
B) two
C) four
D) six
E) insufficient information to answer this question
B
Which protein appears to regulate the entry of cells into an S phase? This protein is also known as the "guardian of the genome."
A) p34
B) p102
C) cyclin
D) p53
E) phosphokinase
D
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.
E
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.
C
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.
B
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.
D
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.
A
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.
E
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.
D
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.
B
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.
A
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.
E
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
D
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
D.Mature skin cells
B.Muscle cells
E.Stem cells
C.Nerve cells
E
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
E
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
A
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
A
Which of the following is not a checkpoint in the cell cycle?
A. The G1/S transition
D. Late metaphase
B. The S/G2 transition
C. The G2/M transition
E. The prophase/metaphase transition
E
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.
A
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
A
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
B
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
A
The drug Gleevec is most closely associated with which of the following molecules?
A. DNA
B. mRNA
C. ATP
D. NADH
E. tRNA
C