Question 1

Which of the following best explains why cancer is difficult to target with vaccines, unlike infectious diseases?

Accepted Answer

Cancer cells are our own cells, so there is no foreign antigen to target.

Question 2

Why are tissues such as skin, intestines, and bone marrow more prone to developing cancer?

Accepted Answer

They require regular cell proliferation, increasing the chance for mutations during cell division.

Question 3

Which equation describes the rate of tumor evolution as subclones diverge and compete within a tumor?

Accepted Answer

$$R = h^2$ 	imes s$$

Question 4

What is the role of oncogenes in the development of cancer?

Accepted Answer

Oncogenes drive expression of CDKs, accelerating cell division.

Question 5

A patient receives chemotherapy, but a few cancer cells survive. What is the most likely outcome according to evolutionary principles?

Accepted Answer

The surviving cells will evolve resistance to the chemotherapy.

Question 6

Why does the risk of cancer increase with age, according to the two-hit hypothesis?

Accepted Answer

It takes time for two mutations to strike both copies of a gene in the same cell.

Question 7

Which of the following best describes the concept of 'intratumor heterogeneity'?

Accepted Answer

Genetic diversity among subclones within a single tumor.

Question 8

What is the main function of tumor suppressor genes in normal cells?

Accepted Answer

They halt or slow down cell cycle progression.

Question 9

A person inherits a mutated copy of a tumor suppressor gene from their parent. According to the two-hit hypothesis, what is the implication?

Accepted Answer

They only need one additional mutation in the same gene to develop cancer.

Question 10

Why is early detection of cancer critical for successful treatment?

Accepted Answer

Early tumors have less genetic variation and are less likely to be resistant to therapy.

Question 11

Which of the following strategies is used to manage the evolution of drug resistance in cancer therapy?

Accepted Answer

Applying weaker or sporadic doses to allow susceptible cells to survive and outcompete resistant cells.

Question 12

What is the expected outcome when a tumor is surgically removed before metastasis occurs?

Accepted Answer

The heritability ($$h^2) of $$cancer traits goes to zero and the population goes extinct.

Question 13

How does exposure to mutagens and carcinogens increase cancer risk?

Accepted Answer

By increasing the likelihood of mutations during cell division.

Question 14

In the context of cancer therapy, what is the advantage of using a two-pronged drug attack based on trade-offs in resistance?

Accepted Answer

It exploits vulnerabilities created by resistance to the first drug, making cells susceptible to the second drug.

Question 15

Which of the following best describes the process of metastasis in cancer?

Accepted Answer

Cancer cells disperse to new locations in the body and establish new populations.

Question 16

Why does applying strong selection pressure (high $$s) $$with chemotherapy often lead to rapid evolution of drug resistance in tumors?

Accepted Answer

Strong selection pressure favors survival of resistant cells, which then proliferate.

Question 17

What is the main reason that multicellular organisms evolved genetic pathways to regulate cell proliferation?

Accepted Answer

To prevent somatic cells from going rogue and dividing uncontrollably.

Question 18

If a mutation strikes only one copy of a 'police' gene in a somatic cell, what is the likely outcome?

Accepted Answer

The cell still has a functional copy and cell cycle regulation remains intact.

Question 19

Which of the following is a real-world example of organ-specific cancer caused by exposure to a mutagen?

Accepted Answer

Chewing tobacco causing lip and throat cancer.

Question 20

According to population genetics, what happens to the relative importance of drift and selection as tumor cell populations grow larger?

Accepted Answer

Selection becomes more important than drift.

Cancer: Evolution, Genetics, and Therapeutic Strategies

Study Guide - Practice Questions