Deck 24: Cancer Genetics

Question 1

Why do cancer researchers study molecular events associated with mitosis?

Answer 1

While mitosis is a basic process related to genetic and general biological studies,it is also a significant event in the cell cycle.The cell cycle is regulated by a variety of gene products,which,when altered by mutation,may lead to cancer.

Question 2

In sporadic cases of retinoblastoma,only two gene mutations are thought to be necessary in the same cell for a tumor to develop.This happens when an organism inherits a mutant allele and a wild- type allele forms the parents.When the wild- type allele is mutated,resulting in tumorigenesis,this process is called,_______ .

A)gain of heterozygosity
B)loss of heterozygosity
C)recombination
D)metastasizing
E)attenuation

Answer 2

loss of heterozygosity

Question 3

Which three stages or transitions in the cell cycle seem to serve as points of control checkpoints)?

Answer 3

G1/S,G2/M,M

Question 4

Describe why cancer cells are more susceptible to chemotherapies and radiation therapies than normal cells.

Question 5

What is the name of the protein that appears to regulate the entry of cells into an S phase? This protein is also known as the "guardian of the genome."

A)cyclin
B)p34
C)phosphokinase
D)p102
E)p53

Question 6

Describe the general relationship that may exist between mutations and cancer.

Question 7

Which of the following general mechanisms appear to be involved in the formation of cancer cells?

A)transdetermination,mutation,allosteric interactions
B)suppression,tabulation,projection
C)genomic instability,DNA repair failure,chromatin modifications
D)inversions,operon formation,methylation
E)RNA failure,DNA phosphorylation,phosphorylation of adenyl cyclase

Question 8

Which of the following proteins function as a cell- cycle regulator and transcription factor that can result in cell death apoptosis)to a damaged cell?

A)p53
B)p102
C)p34
D)cyclin
E)phosphokinase

Question 9

What is the name of the protein that combines with cyclins to exert local control of the cell cycle?

A)cyclin- dependent kinase
B)integrase
C)ATPase
D)hexokinase
E)phosphatase

Question 10

Mutant versions of genes that are normally involved in promoting the development of cancer are known as_______ .

A)oncogenes
B)malignant genes
C)proto- oncogenes
D)attenuators
E)tumor suppressors

Question 11

Mutations in the ras gene family induce normally quiescent cells to proceed into the replication cycle.This converts the ras gene from a _______gene to a _______ gene.

A)proto- oncogene; oncogene
B)mutant; oncogene
C)oncogene; proto- oncogene
D)tumor suppressor; proto- oncogene
E)pseudooncogene; proto- oncogene

Question 12

Signal transduction is best described as_______.

A)communication between nuclei of two organisms
B)communication between cells through physical interaction
C)transmission of signals external to the cell to the nucleus
D)transmission of signals from cancer cells to normal cells

Question 13

What is the significance of CDK/cyclin interactions with respect to cancer cell proliferation?

Question 14

Chronic myelogenous leukemia appears to be associated with a chromosomal rearrangement.How is a chromosomal rearrangement responsible for this disease?

Question 15

Name two of the classes of proteins that combine to directly control progression through the cell cycle.

Question 16

Briefly describe what a passenger mutation is with respect to cancer genetics.

Question 17

Provide a definition of cancer at the genetic level.

Question 18

A loss- of- function mutation in BAX proteins could eliminate apoptotic response in cell.Describe why this type of mutation is a passenger mutation and not a driver mutation.

Question 19

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)carrier mutations
B)indirect mutations
C)insignificant mutations
D)passenger mutations
E)alteration mutations

Question 20

Describe how tumor- suppressor genes keep cells in check.

Question 21

Chronic myelogenous leukemia is a cancer found in white blood cells.What is its supposed genetic basis of this disease?

Question 22

Describe the normal function of a tumor- suppressor gene.

Question 23

Describe the molecular nature of mutation,as related to cancer,in a ras gene.

Question 24

Describe the cellular and molecular function of the ras gene family and the consequences of mutations in ras.

Question 25

Many of the known cancers are a result of _____ .

A)the genetic stability of the human genome
B)the non- carcinogenic nature of our environment
C)the genetic instability of the human genome
D)exercising regularly

Question 26

What are two properties that various types of cancer cells share?

Question 27

Most cancer- causing animal viruses are RNA viruses called _____ .

A)neoviruses
B)retroviruses
C)DNA viruses
D)classic viruses

Question 28

Which category of genetic changes does not lead to the formation of oncogenes?

A)point mutations
B)copy number changes
C)translocations
D)correct DNA repair

Question 29

In what way can loss of heterozygosity lead to cancer?

Question 30

Briefly describe the following types of genes: tumor- suppressor gene,proto- oncogene,and oncogene.

Question 31

Describe three genetic mechanisms whereby proto- oncogenes can become overexpressed.

Question 32

As more is learned about cancer,it has become clear that cancer,with few exceptions, _____.

A)is only dependent on the inherited genetics
B)is a result of genetics and environmental factors
C)is 100% dependent on inherited genetics
D)has no genetic basis

Question 33

In what way might a virus contribute to cancer formation?

Question 34

Most cancers arise due to mutations in somatic cells,if someone has a predisposition to cancer,what genetic circumstance likely exists?

Question 35

Provide a simple definition of a carcinogen.

Question 36

Much has been written about p53 in terms of cancer biology.What is p53,and what is its significance?

Question 37

What is the name of a normal gene that serves to promote cellular division?

A)post- oncogene
B)cancer gene
C)proto- oncogene
D)oncogene

Question 38

The genetic difference between familial retinoblastoma and sporadic retinoblastoma appears to be based on those with the familial form starting out being _____,whereas those with the sporadic form start out being _____
.

Question 39

Most p53 mutations that result in cancer are a result of loss of function in p53.Describe one method through which a gain- of- function mutation in p53 could cause cancer.

Question 40

All of these are known to cause cancer EXCEPT _____.

A)chronic infections
B)some viruses
C)radiation
D)DNA repair

Question 41

All of the following are checkpoints in the cell cycle EXCEPT _____ .

A)G1/S
B)M
C)M/G1
D)G2/M

Question 42

Which virus type results in the immediate onset of cancer phenotype upon infection of a host?

A)adenovirus
B)acute transforming retrovirus
C)lentivirus
D)retrovirus

Question 43

Any agent that causes damage to DNA is a potential _____ .

A)pollutant
B)proto- oncogene
C)oncogene
D)carcinogen

Question 44

Examined cancer cells from the lungs of smokers demonstrate which of the following?

A)mutation rates that are similar to those in a smoker's heart
B)normal mutation rates compared to non- smokers
C)unregulated methylation patterns
D)the occurrence of tumor- suppressor mutations is less in the lung than the throat

Question 45

A tumor- suppressor gene normally functions to _____ .

A)induce cell division
B)create mutations forming cancer cells
C)repair cancer cells
D)suppress cell division

Question 46

A retrovirus uses _____to make a DNA copy of RNA.

A)cyclins
B)ras proteins
C)reverse transcriptase
D)CDKs

Question 47

The gene p53 is called the _____because it corrects mutations in the spindle apparatus before nondisjunction can occur.

A)M phase checkpoint monitor
B)tumor- suppressor monitor
C)guardian of the genome
D)S phase checkpoint monitor

Question 48

When considered as a root cause for cancer,which of the following is linked to at least 17 types of human cancer?

A)smoking
B)not exercising regularly
C)eating a low- fat diet
D)eating a high- fat diet