Deck 40: Cancer: Cell Division Out of Control

Question 1

Which of the following statements about retinoblastoma is false?

A) Retinoblastoma is caused by a mutation in chromosome 13.
B) Retinoblastoma results from a lack of cell division.
C) Retinoblastoma is characterized by the presence of a tumor in a child's retina.
D) The cause of retinoblastoma was determined by examining karyotypes.

Answer 1

B

Question 2

Cancer in humans is caused

A) only by environmental factors.
B) only by genetic factors.
C) by neither environmental nor genetic factors.
D) by both environmental and genetic factors.

Answer 2

D

Question 3

Which of the following is not true of cell division?

A) A cell has no control over how often it divides.
B) Negative growth regulators are used to halt cell division.
C) Numerous cellular proteins are affected by cell division signals.
D) Uncontrolled cell division can cause cancer.

Answer 3

A

Question 4

This diagram shows the two states in which the Rb protein is found in the cell.
In which state would you find the Rb protein in a cell that needs to undergo rapid cell division?

A) State A
B) State B
C) Neither, Rb is not involved in cell division.
D) A portion of the Rb protein in the cell must be in each state.

Question 5

Rapid cell proliferation can result from

A) contact inhibition.
B) a cell ignoring a negative growth regulator.
C) a mutation inhibiting the action of a positive growth regulator.
D) the surgical removal of a benign polyp.

Question 6

Peyton Rous's experiments with chicken tumors led to the discovery that

A) chickens are immune to cancer.
B) cancer cannot be transferred from one chicken to another.
C) bacteria can cause cancer.
D) viruses can cause cancer.

Question 7

A physical, chemical, or biological agent that causes cancer is called

A) a virus.
B) a carcinogen.
C) an oncogene.
D) a regulatory protein.

Question 8

When a mutant receptor protein no longer requires a growth factor to activate it, the result is

A) reduction in cell division.
B) extra binding sites.
C) uncontrolled cell division.
D) lack of protein products.

Question 9

A tumor suppressor is a(n)

A) negative growth regulator.
B) positive growth regulator.
C) oncogene.
D) sarcoma virus.

Question 10

A tumor that has gained the ability to spread throughout the body, generally with life-threatening consequences, is known as a _______ tumor.

A) benign
B) polyp
C) malignant
D) growth-promoting

Question 11

Studies of retinoblastoma indicated that this type of cancer is caused by

A) a virus.
B) Rous's bacteria.
C) growth factors.
D) a missing gene.

Question 12

Phosphorylation resulting from the influence of a growth factor

A) causes the Rb protein to release its target protein.
B) inhibits the target gene of the Rb protein.
C) turns the Rb protein into an energy-carrying molecule needed for cell division.
D) causes its target protein to become inactive.

Question 13

The Rb protein inhibits

A) a gene that promotes cell division.
B) a protein that promotes cell division.
C) the reproduction of a cancer causing virus.
D) a protein that inhibits cell division.

Question 14

Which of the following is not true of cancer?

A) Cancer involves cell proliferation.
B) Cancer can be caused by viruses.
C) Cancer results from a balanced production of positive and negative growth regulators.
D) Cancer involves the loss of a cell's ability to control cell division.

Question 15

If a cell's p53 genes are inactivated, the cell

A) loses control over cell division.
B) stops dividing.
C) no longer makes proto-oncogenes.
D) activates tumor suppressors.

Question 16

Even though all people are exposed to potential carcinogens on a daily basis, we do not all develop cancer. Why?

A) The carcinogens are too weak to cause mutations in our DNA.
B) Human cells are resistant to carcinogens until we are approximately 50 years old.
C) DNA repair mechanisms are able to correct some of the mutations that occur.
D) Humans' oncogenes protect us from most of the carcinogens we are exposed to.

Question 17

The fact that the human genome contains proto-oncogenes means that

A) there is nothing we can do to reduce our chance of developing cancer.
B) our genomes are constantly producing cancerous cells.
C) the disruption of certain cellular controls can lead to cancer.
D) we will all develop cancer during our lifetimes.

Question 18

Normal cellular genes that can be mutated into cancer-causing genes are known as

A) oncogenes.
B) growth factors.
C) proto-oncogenes.
D) viral proteins.

Question 19

Which of the following is not likely to cause a cell to become cancerous?

A) mutation
B) meiosis
C) chemical pollutants
D) cigarette smoke

Question 20

A woman who has already had children develops skin cancer from overexposure to the sun. Is it possible for her children to have inherited this cancer from her?

A) No, because only mutations that occur in gametes can be passed on to the next generation.
B) No, because any cancer that develops after a person is an adult cannot have a genetic component.
C) Yes, because almost all cancers are caused by genetic factors.
D) Yes, because the woman's children have exactly the same genome as their mother does.

Question 21

For cancer to form in the presence of a tumor suppressor gene, which of the following is necessary?

A) Both copies of the tumor suppressor gene must be inactivated.
B) The tumor suppressor gene must be activated.
C) One copy of the tumor suppressor gene must be inactivated.
D) The tumor suppressor gene is not involved in cancer formation.

Question 22

When cells are stimulated to divide,

A) proto-oncogenes are inactivated.
B) tumor suppressors are activated.
C) tumor suppressors are inactivated.
D) oncogenes become proto-oncogenes.

Question 23

Rous demonstrated that something smaller than a bacterium could cause cancer by

A) putting a chicken with cancer in the same cage as a healthy chicken.
B) injecting healthy chickens with a mixture of bacteria and tumor cells.
C) injecting healthy chickens with carefully filtered extracts from tumor cells.
D) exposing healthy chickens to tumor cells from humans.

Question 24

If exposure to sunlight causes a mutation in a single proto-oncogene in a diploid cell so that it becomes hyperactive,

A) the remaining un-mutated proto-oncogene will prevent the cell from becoming cancerous.
B) tumor suppressor cells will destroy the proteins made from the mutated gene.
C) the cell might produce a protein that pushes it into rapid cell division.
D) the mutated gene will be inactivated by phosphorylation.

Question 25

Proto-oncogenes, which produce many of the proteins used in a signal cascade, are found

A) only in Golgi bodies.
B) only on the cell's surface.
C) only in the cell's nucleus.
D) throughout the cell.

Question 26

Which of the following statements about viruses is false?

A) Viruses can cause cancer.
B) Viruses can be used to destroy cancer cells.
C) Viruses do not contain a nucleic acid.
D) Viruses take over a cell's machinery in order to reproduce.

Question 27

Normal cell division requires

A) inactivated proto-oncogenes and activated tumor suppressor genes.
B) inactivated proto-oncogenes and inactivated tumor suppressor genes.
C) activated proto-oncogenes and activated tumor suppressor genes.
D) activated proto-oncogenes and inactivated tumor suppressor genes.

Question 28

A pesticide was found to cause cancer in laboratory mice. Which of the following would be the most reasonable hypothesis to pursue?

A) The pesticide mutates an oncogene to a proto-oncogene.
B) The pesticide mutates both oncogenes to proto-oncogenes.
C) The pesticide mutates one oncogene to a proto-oncogene and one tumor suppressor gene to an inactive form.
D) The pesticide mutates both tumor suppressor genes to inactive forms.

Question 29

Examine the figure below.
In this example, excessive cell division is the result of a mutation that results in

A) excessive activity of a proto-oncogene.
B) excessive activity of a tumor suppressor protein.
C) changes in a cell's cytoskeleton.
D) inactivity of two tumor suppressor proteins.

Question 30

In many human colon tumors, the beginning of true malignancy is the result of the

A) loss of part of chromosome 18.
B) inactivation of both oncogenes.
C) inactivation of both proto-oncogenes.
D) arrival of cancerous cells from other parts of the body.

Question 31

Which of the following kinds of molecules are the least likely to be produced by a proto-oncogene?

A) receptor proteins
B) protein kinases
C) growth factors
D) ribosomal proteins

Question 32

Tumor suppressor proteins

A) produce growth factor signal cascades.
B) remove growth factors from DNA.
C) inactivate components of growth factor signal cascades.
D) are produced by growth factors.

Question 33

The cells in many large polyps in the human colon usually contain

A) normal tumor suppressor genes and at least one oncogene.
B) one inactive and one active copy of a tumor suppressor gene and normal proto-oncogenes.
C) two inactive copies of a tumor suppressor gene and two proto-oncogenes.
D) two inactive copies of a tumor suppressor gene and one oncogene.

Question 34

Adducts are most likely to lead to cancer in cells

A) that have a long cell cycle.
B) that have a short cell cycle.
C) in G0.
D) undergoing meiosis.

Question 35

A protein is identified that starts a signal cascade leading to the activation of a gene that promotes cell division. This protein is coded for by a

A) tumor supressor gene.
B) oncogene.
C) proto-oncogene.
D) carcinogen.

Question 36

The p53 protein is critical to the regulation of the cell cycle because it

A) halts cell division when necessary, allowing the cell to repair damaged DNA
B) causes cells with heavily damaged, un-repairable DNA to commit "suicide."
C) prevents the cell from dividing at inappropriate times
D) all of the above

Question 37

In order for a virus to reproduce, it must insert its DNA into the host cell's genome. How might this cause cancer in the host?

A) The viral DNA could insert a gene that controls cell division into the host's DNA.
B) Because the host cell is much smaller than the virus, the host cell must expand until it becomes a tumor large enough to hold the virus.
C) The virus could turn off an oncogene.
D) Viruses cannot cause cancer.

Question 38

A mutated version of a virus that cannot disable the p53 gene can be used to

A) turn off the host cell's enzymatic activities.
B) repair defective genes.
C) turn off signal cascades.
D) kill cancer cells.

Question 39

Examine the graph below.
This graph shows that

A) people over the age of 45 are more likely to smoke cigarettes than those between 18 and 24 years of age.
B) nonstudents are more likely to use most forms of tobacco than college students.
C) students enrolled in college part time are unlikely to smoke cigars.
D) college students who use tobacco are more likely to get cancer.

Question 40

Why was a version of Rous's virus that did not cause cancer important to our understanding of how viruses cause cancer?

A) This discovery showed that viruses do not actually cause cancer.
B) The existence of another version of the virus proved that viruses also cause cancer in humans.
C) The genes in the newly discovered virus were the first known tumor suppressor genes.
D) Comparison of the different versions of the virus indicated which genes in the virus caused cancer.

Question 41

Rous's work on sarcomas in chickens led to the discovery of the first animal tumor-causing _________.

Question 42

_______ starts with a single cell that loses its ability to control cell division.

Question 43

A physical, chemical, or biological agent that causes cancer is a ___________.

Question 44

In order to be healthy, an organism must stop all cell division activities.

Question 45

For proper cell division to occur, the activity of proto-oncogenes must be balanced by the activity of _____________ genes.

Question 46

Some carcinogens can bind with DNA and form a(n) _______ that causes mistakes in DNA synthesis.

Question 47

Under normal conditions growth factors activate ____________ and inactivate ______________ genes.

Question 48

A benign growth is harmless.

Question 49

An overactive viral protein _______ can turn on signal cascades in a host, thus leading to cancer.

Question 50

Cancer-causing genes are known as _______.

Question 51

The cancer retinoblastoma occurs as a result of the absence of the _____ gene.

Question 52

Most cancers are caused by a combination of environmental factors.

Question 53

Cancer cells cause tumors in other parts of the body by traveling through the _______.

Question 54

A harmless proliferation of cells in a human colon would be called a(n) ________ polyp.

Question 55

Mutations cause changes in __________ produced by a gene.

Question 56

A _______ is a harmless growth that may occur in the colon, for example, without being cancerous.

Question 57

The addition of a phosphate group to a protein activate the protein by causing it to change its ___________.

Question 58

Positive growth regulators increase the rate of _____________.

Question 59

_______ cancers spread throughout the body, with life-threatening consequences.

Question 60

Cancer-causing chemicals increase the risk of cancer by promoting _______ in the DNA, causing changes in the DNA base sequences.

Question 61

All viruses cause cancer.

Question 62

A cure for cancer would stop all cell division in an organism.

Question 63

People who quit smoking live longer than those who don't quit smoking.

Question 64

A virus can insert its genes into the DNA of the host cell, thus ensuring that all daughter cells receive a copy of the viral genes.

Question 65

In the future viruses may cure as well as cause cancer.

Question 66

The mutation of p53 generally results in the formation of a malignant tumor.

Question 67

One or two mutations are often the cause of cancer.

Question 68

Why is cancer more common in older people?

Question 69

Cigarette smoking is the leading cause of cancer deaths in the United States.