Deck 12: Genes and Cancer

Question 1

Hereditary nonpolyposis colon cancer (HNPCC)requires only one mutational step to initiate the formation of a cancer cell.

Answer 1

False

Question 2

There are no direct-to-consumer genetic tests available that screen for breast cancer susceptibility.

Answer 2

False

Question 3

Hereditary nonpolyposis colon cancers (HNPCC)____.

A) are rare in the United States, but common in Europe
B) begin with a mutation in the APC gene
C) are caused by one-of-a-kind DNA sequences called microsatellites 
D) are caused by one mutation in a single gene
E) are caused by several mutations in several different genes

Answer 3

E

Question 4

Many specialized cells,such as white blood cells,____.

A) remain in G0 until stimulated by external signals to reenter the cell cycle and divide
B) remain in S until hormonal signals cause the cell to reenter the cell cycle and divide
C) divide continuously and never transition to G0
D) mutate into other cell types by signals from bone marrow cells
E) skip anaphase in order to avoid the high likelihood of mutation during this phase of mitosis

Question 5

During the M checkpoint,the cell ____.

A) proceeds to interphase and completes DNA replication
B) proceeds to G2 phase and the cell prepares to divide
C) proceeds to S phase or enters inactive G0 state
D) monitors attachment of spindle fibers to chromosomes
E) monitors completion of DNA synthesis and DNA damage

Question 6

The ras proto-oncogene family is a group of related genes that slow or stop the progression of cancer.

Question 7

About ____ of all cancer cases have a hereditary component.

A) 1% to 3%
B) 5% to 10%
C) 10% to 15%
D) 15% to 20%
E) 25% to 35%

Question 8

Viral infection is a major cause of cancer.

Question 9

Stem cells ____.

A) have the property of self-renewal by division
B) are the least likely to give rise to cancer
C) do not have the ability to divide
D) are immature cells that become nerve tissue susceptible to cancer
E) are found only in cancerous tumors

Question 10

Radiation and chemotherapy are the best treatments for cancer because they are very specific and destroy only cancerous cells.

Question 11

According to the American Cancer Society,30% of all cancer deaths in the U.S.are due to ____.

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

Question 12

The translocation seen in the Philadelphia chromosome in myelogenous leukemia represents ____.

A) a chromosomal aberration that is secondary to the cancer
B) a chromosomal aberration that is caused by the development of cancer
C) a proto-oncogene that has been deleted from chromosome 6 and inserted into chromosome 7
D) a specific chromosomal aberration accompanying a specific cancer
E) the evidence of exposure to chemical carcinogens

Question 13

Cancer-causing mutations of the cell cycle ____.

A) increase the speed of the cycle
B) cause the cell to bypass checkpoints in the cycle
C) eliminate one or more stages of the cycle
D) interfere with S phase of the cycle
E) stop the cycle and cause a build-up of cell toxins

Question 14

Cancer causing mutations are always the result of chromosomal rearrangements.

Question 15

A proto-oncogene ____.

A) always becomes cancerous
B) causes cancer
C) encodes tumor-suppressing proteins
D) repairs DNA
E) regulates cell division

Question 16

The mutant BRCA1 gene imparts a dominantly inherited predisposition to breast cancer.

Question 17

Stem cells have the ability to differentiate to form specific cell types,which divide only slowly or not at all.

Question 18

Most of the somatic cells in the body are structurally and functionally specialized and do not divide.

Question 19

A characteristic of all cancers is that ____.

A) the cells divide continuously
B) they have a benign form and a deadly form
C) several mutations in several different genes are required in order for cancer to develop
D) they are always due to a chromosome disjunction mutation
E) the rapid proliferation of cells is required

Question 20

About one in three people will be diagnosed with cancer at some time in his/her life.

Question 21

One of the properties of cancer is its ability to spread,or ____________________,to other sites in the body.

Question 22

All epithelial cells in the inner lining of the large intestine that are heterozygous for an APC mutation ____.

A) are able to control cell division with the second copy of the APC gene
B) become cancerous
C) require additional mutations in downstream genes to become cancerous
D) cause the transition from polyps into colon cancer
E) can partially escape control of the cell cycle and lead to the formation of clusters of polyps

Question 23

Drug therapies that target only cancer cells rather than all dividing cells in the body stop the growth of cancer by blocking the action of ____________________ proteins on the growth and division on malignant cells.

Question 24

When MSH2 and MLH1 are inactivated by mutation,DNA repair is defective and ____________________ mutation rates increase by at least 100-fold.

Question 25

The field of epigenetics has opened the way for the development of a new class of anticancer drugs ____.

A) that are very similar to many chemotherapy treatments but are much more targeted and effective
B) that stop mutations before they occur in individuals with a predisposition to certain kinds of cancer
C) that increase the level of methylation in cancer cells
D) used specifically to treat breast cancer because the key genes involved in this cancer cannot be epigenetically modified 
E) because of the discovery that epigenetic modification of key genes is important in some cancers and the fact that epigenetic changes are reversible

Question 26

During metabolism,cancer-causing ____ are generated.

A) BRCA1 genes
B) methyl amines
C) reactive oxygen species (ROS)
D) BCR-ABL proteins
E) mutated tRNA fragments

Question 27

In the atmosphere,____________________depletion in certain regions of the globe contributes to increased levels of UV radiation exposure,which in turn is associated with increases in skin cancer frequency.

Question 28

If a cell begins to divide in an uncontrolled way,it ____.

A) will always form a cancerous tumor
B) may form a benign tumor
C) is a sign of metastasis
D) is considered a malignant tumor
E) signals uncontrolled cell division in other parts of the body

Question 29

Genes that turn off or decrease the rate of cell division are known as ____________________ genes.

Question 30

In most cases,cancer-causing mutations ____.

A) accumulate over a number of years
B) accumulate very quickly within a single cell
C) metastasize within a short time
D) must all occur on the q arm of a chromosome
E) occur during the G0 phase of the cell cycle

Question 31

Epigenetics is the study of heritable alterations in gene expression caused by ____.

A) mechanisms that do not alter any DNA sequence
B) the mutation of a single gene
C) translocations between alleles
D) environmental factors
E) replication and then improper repair of DNA coding mistakes

Question 32

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

Question 33

The five-year survival rate of ____________________ cancer is only 13%.

Question 34

Abnormal epigenetic patterns of DNA ____________________ are associated with many types of cancer,and the removal of ____________________ groups can activate genes involved with cell growth and can increase genomic instability.

Question 35

With the sequence of the gene-coding regions of the human genome in hand and the development of newer sequencing methods,scientists ____.

A) now know that the types of mutations present in all cancers are very similar
B) can now sequence and analyze the protein-coding genes in cancer cells
C) are still unable to systematically identify all the mutations present in a cancer cell
D) found that the number of mutational events that occur during the transition from normal to malignant cells is much smaller than previously thought
E) found that most tumors had at least 100 mutations in common with any other tumor, emphasizing the common origin of cancer

Question 36

Common alleles of genes other than BRCA1 ____.

A) dictate the types of mutations that occur in BRCA2
B) cause uncontrolled division of the BRCA2 gene
C) cause the interruption of the cell cycle in any cell containing a BRCA2 mutation
D) have a strong influence on whether a carrier will develop breast cancer
E) have very little influence on whether a carrier will develop breast cancer

Question 37

The RB1 tumor-suppressor gene ____.

A) controls the G2/M checkpoint
B) controls the G1/S checkpoint
C) is overactive in cases of retinoblastoma
D) is overactive in cases of breast cancer
E) is overactive in cases of leukemia

Question 38

In rapidly dividing cells,expression of BRCA1 and BRCA2 genes is the highest during the ____.

A) mitosis to cytokinesis transition
B) G1/S transition and into S phase
C) G2/mitosis transition
D) S/G2 transition
E) metaphase to anaphase transition

Question 39

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

Question 40

A(n)____________________ between chromosome 9 and chromosome 22 in chronic myelogenous leukemia results in a Philadelphia chromosome.

Question 41

Give a possible interpretation of the finding that the number of mutational events that occur during the transition from normal to malignant cells is much larger than previously thought.

Question 42

Explain why epithelial cells are the source of 80% to 90% of all cancers.Then list at least two types of epithelial cells,and at least four types of cancer for which they are the source.

Question 43

BRCA2 maps to the long arm of chromosome 13 and may be responsible for the majority of inherited predispositions for breast cancer not caused by ____________________.

Question 44

Progressive chromosomal changes as cancer develops are related to the loss of the ability to repair ____________________ in cancer cells.

Question 45

Outline the three criteria recommended by the American Society of Clinical Oncology (ASCO)for when cancer tests should be done.

Question 46

The cancer drugs Gleevec and Herceptin bind to receptor ____________________ and stop the growth of cancer cells.

Question 47

List four lines of evidence that support a link between cancer and genetics.Describe the ultimate cause of cancer and how an individual's life-style might reduce the chances of developing cancer.

Question 48

Leukemia is a type of cancer that involves the uncontrolled division of ____________________ cells.

Question 49

In the familial form of retinoblastoma,individuals who inherit one mutant allele of the RB1 gene have an 85% chance of developing retinoblastoma and other cancers.Explain why,when these individuals carry only one copy of the mutant gene,there is such a high incidence of cancer in these RB1 heterozygotes.

Question 50

One of the steps in converting normal cells into cancerous cells may be the ____________________ and silencing of both copies of the NOEY2 gene.

Question 51

In some families,members inherit a mutant allele that causes a(n)____________________ to cancer.

Question 52

Outline the four characteristics of cancer.

Question 53

Outline the two parts of the eukaryotic cell cycle and describe the three main checkpoints in cell cycle regulation.

Question 54

An autosomal dominant trait called familial adenomatous polyposis (FAP)results in the development of polyps and benign growths in the colon and is coupled with ____________________ instability.

Question 55

A reciprocal translocation between two chromosomes can result in the formation of a(n)____________________ gene.

Question 56

All the cells in a cancerous tumor are ____________________ directly descended from one cell.

Question 57

Mutant forms of proto-oncogenes are called ____________________.

Question 58

Explain how the loss of heterozygosity (LOH)leads a cell to become cancerous.

Question 59

List three properties that all forms of cancers share and summarize the origin of these properties.

Question 60

Summarize two pathways to colon cancer.