Question 1

Which of the following best describes the difference between CRISPR and siRNA in gene regulation experiments?

Accepted Answer

CRISPR causes a permanent knockout of gene expression, while siRNA causes a temporary knockdown.

Question 2

A fertilized frog egg divides from one cell into millions over 36 hours. What process is responsible for this rapid increase in cell number?

Accepted Answer

Cell division

Question 3

What is the primary risk if cell division occurs unchecked in multicellular organisms?

Accepted Answer

Cancer may develop due to uncontrolled cell proliferation

Question 4

What is the main function of cell cycle checkpoints?

Accepted Answer

To ensure cells only divide when conditions are appropriate and DNA is intact

Question 5

If a cell fails to meet the requirements of a cell cycle checkpoint, what is the most likely outcome?

Accepted Answer

The cell will undergo apoptosis

Question 6

Which protein is most directly involved in triggering apoptosis when DNA damage is detected at the G1 checkpoint?

Accepted Answer

p53

Question 7

Why do cancer cells often acquire 'immortality' compared to normal cells?

Accepted Answer

They express telomerase, maintaining chromosome ends and allowing indefinite division

Question 8

Which of the following is NOT a way cancer cells evade normal controls on cell growth?

Accepted Answer

Increasing DNA repair efficiency

Question 9

What is the significance of major chromosomal abnormalities in cancer cells?

Accepted Answer

They indicate increased genomic instability, which can drive tumor progression

Question 10

Mutations in which type of gene would most likely speed up the accumulation of additional mutations in a tumor?

Accepted Answer

DNA-repair genes

Question 11

Which of the following statements about environmental factors and cancer is correct?

Accepted Answer

Most environmental factors cause somatic mutations that trigger excessive cell division

Question 12

Which of the following best describes the role of proto-oncogenes in cancer?

Accepted Answer

They encode proteins needed for cell cycle progression and can become oncogenes through gain-of-function mutations

Question 13

How do tumor suppressor genes typically act to prevent cancer?

Accepted Answer

By encoding proteins that slow down the cell cycle or promote apoptosis

Question 14

HER2 overexpression in breast cancer is most commonly due to which genetic event?

Accepted Answer

Gene amplification

Question 15

Which targeted therapy is used to treat HER2-positive breast cancer by binding to the HER2 receptor?

Accepted Answer

Herceptin

Question 16

What is the main goal of whole-genome sequencing in cancer therapy?

Accepted Answer

To compare normal and cancer cells from the same patient and identify driver mutations for targeted therapy

Question 17

Which of the following best explains the feedback loop between cell proliferation and genomic instability in tumor progression?

Accepted Answer

Increased cell proliferation leads to more mutations, which further increase proliferation and instability

Question 18

Which of the following is a hallmark of cancer cells that allows them to metastasize?

Accepted Answer

Loss of anchorage and acquisition of mobility

Question 19

A patient’s tumor is found to have a loss-of-function mutation in both copies of a tumor suppressor gene. What is the most likely consequence?

Accepted Answer

Increased cell proliferation due to loss of cell cycle brakes

Question 20

Which of the following best describes the clonal origin of cancer?

Accepted Answer

All tumor cells are descendants of a single cell that acquired the initial cancerous mutation

Genetic Mechanisms of Cancer: Cell Cycle, Mutations, and Therapeutic Targets

Study Guide - Practice Questions