Ch 20B Assignment

Question 1

About half of all cancers are thought to arise by infection with viruses, bacteria, or parasites.

True
False

Answer 1

False

Question 2

An enzyme that normally suppresses PI3K acttivity is inactivated. This is expected to lead to_____.

excessive cell growth
decreased cell growth
inhibition of TOR activity
inhibition of AKT activity

Answer 2

excessive cell growth

Question 3

Complete loss of function of Rb by just one somatic event is seen in _____.

nonhereditary retinoblastoma

hereditary retinoblastoma

normal and healthy indivuduals

hereditary familial adenomatous polyposis coli

Answer 3

hereditary retinoblastoma

Question 4

What is Src?

It functions as a tumor suppressor

It’s loss drives cancer growth

It is a proto-oncogene

It is inactivated through viral DNA integration

Answer 4

It is a proto-oncogene

Question 5

Which of the following proteins is NOT encoded by a proto-oncogene?

Ras
PTEN
EGF receptor
Myc

Answer 5

PTEN

Question 6

Which of these mutations lead to cancer?

Inactivating mutations in tumor suppressor

Inactivating mutations in proto-oncogene

Inactivating mutations in oncogene

Passenger mutations

Answer 6

Inactivating mutations in tumor suppressor

Question 7

Which of the following stressors can lead to p53 stabilization and activation?

Hypoxia
DNA damage
Telomere loss
All of the above

Answer 7

All of the above

Question 8

The similarity between Apc in colon cancers and Rb in retinoblastomas is that both ________.

are mutated in at least one gene copy in patients with a hereditary form of the cancer.

are activated by missense mutations in both hereditary and nonhereditary forms of cancer.

should be activated in both copies to cause the nonhereditary form of the cancer.

All of the above.

Answer 8

are mutated in at least one gene copy in patients with a hereditary form of the cancer.

Question 9

Mutation in which of the following genes is most prevalent in a rare hereditary form of colorectal cancer?

Beta-Catenin
K-Ras
Rb
APC

Answer 9

APC

Question 10

Mutations in p53 and Rb contribute to many cancers. What type of mutations are these?

Loss-of-function mutations in both genes

Loss-of-function mutation in p53 and gain-of-function mutation in Rb

Gain-of-function mutation in p53 and loss-of-function mutation in Rb

Gain-of-function mutations in both genes

Answer 10

Loss-of-function mutations in both genes

Question 11

Cancer-inducing mutations in these genes are commonly seen in the form of nonsense (truncating) mutations that abort protein synthesis. What are these genes likely to be?

tumor suppressors
oncogenes
proto-oncogenes
passenger mutants

Answer 11

tumor suppressors

Question 12

Genetically knocking out both copies of the p53 gene in rats …

is embryonic lethal.

increases cell death by apoptosis, leading to developmental defects.

leads to higher cancer rates but normal development is mostly unaffected.

does not have any effect on the rats.

Answer 12

leads to higher cancer rates but normal development is mostly unaffected.

Question 13

Which of these mutations occur as a result of genomic instability but are not primary regulators of tumor development?

driver mutations

passenger mutations

inactivating mutations in a tumor suppressor

activating mutations in an oncogene

Answer 13

passenger mutations

Question 14

Which of the following is an epigenetic change that coud inactivate a tumor suppressor?

Packing gene into heterochromatin

Gene amplification

Missense mutations that lead to codon changes

Protein truncation by insertion of a stop codon

Answer 14

Packing gene into heterochromatin

Question 15

Which statement about Cancers is FALSE?

Cancer can be induced by infectious agents such as viruses.

Most cancers originate from a single aberrant cell.

The earlier a cancer is diagnosed, the better the chances are for a cure.

Cancers become less heterogenous as they develop

Answer 15

Cancers become less heterogenous as they develop

Question 16

Which of the following sequential barriers to metastasis is the easiest to overcome for cancer cells in general?

Vessel entry through acquisition of local invasiveness

Exit from the blood into a remote tissue or organ

Initial growth of cells in the foreign tissue

Persistence of growth in the remote site

Answer 16

Exit from the blood into a remote tissue or organ

Question 17

Which group would you expect to have loss-of-function mutations in the DNA mismatch repair system genes MSH2 and MLH1 as their primary driver mutations?

HNPCC, which has an almost normal karyotype

non-HNPCC, which has a grossly abnormal karyotype

FAP, which has an almost normal karyotype

FAP, which has a grossly abnormal karyotype

Answer 17

HNPCC, which has an almost normal karyotype

Question 18

Cancer-inducing mutations in these genes include gene duplications and these genes are likely to be……………

Cdk inhibitors

tumor suppressors

cell cycle inhibitors

oncogenes

Answer 18

oncogenes

Question 19

Bioluminescence imaging can track cancer cells in mice by capturing the activity of which of the following proteins?

Tyrosine kinase
Luciferin
Luciferase
Tumor suppressor

Answer 19

Luciferase

Question 20

Which of the following is NOT a consequence of high AKT activity?

increased protein synthesis

increased lipid synthesis

increased cell death

increased cell growth

Answer 20

increased cell death