Question 1

A genome-wide association study (GWAS) identifies several single nucleotide polymorphisms (SNPs) associated with increased risk for Type 2 diabetes. Which of the following best explains why GWAS often implicates multiple genes rather than a single gene for complex diseases?

Accepted Answer

Multiple genes, each with small effects, and environmental interactions contribute to disease risk.

Question 2

A patient with a CYP2C9 variant metabolizes warfarin much more slowly than average. Based on pharmacogenomics, what is the most likely clinical consequence?

Accepted Answer

The patient will have increased sensitivity and risk of bleeding at standard doses.

Question 3

Which of the following is a major limitation of GWAS data when translating findings to clinical care?

Accepted Answer

GWAS often fails to account for gene-environment interactions and missing heritability.

Question 4

Which of the following best distinguishes gene editing (e.g., CRISPR-Cas9) from traditional gene therapy?

Accepted Answer

Gene editing modifies the existing DNA sequence, while gene therapy adds a new functional gene.

Question 5

A researcher uses RNA interference (RNAi) to silence an oncogene in cancer cells. Which of the following best describes the mechanism by which siRNA achieves gene silencing?

Accepted Answer

siRNA binds to the target mRNA, leading to its degradation and reduced protein synthesis.

Question 6

Which of the following therapies is most appropriate for a patient with HER2-positive breast cancer?

Accepted Answer

Trastuzumab, a monoclonal antibody targeting HER2.

Question 7

Why do cancer cells preferentially use aerobic glycolysis (the Warburg effect) even when oxygen is available?

Accepted Answer

Aerobic glycolysis supports rapid biosynthesis of macromolecules needed for proliferation.

Question 8

A tumor is found to be localized, non-invasive, and composed of cells that closely resemble normal tissue. Which classification best fits this tumor?

Accepted Answer

Benign tumor

Question 9

Which stage of cancer progression is characterized by the tumor acquiring the ability to evade the immune system and resist apoptosis?

Accepted Answer

Evasion

Question 10

A patient is diagnosed with triple negative breast cancer (ER–, PR–, HER2–). Which of the following best explains why this subtype is more difficult to treat?

Accepted Answer

It lacks hormone and HER2 receptors, so targeted therapies are ineffective.

Question 11

Which inheritance pattern is most likely if a genetic disease appears in every generation and affects both males and females equally?

Accepted Answer

Autosomal dominant

Question 12

A mutation in the TP53 gene is found in a patient's tumor. What is the most likely consequence of this mutation?

Accepted Answer

Loss of DNA damage checkpoint control, leading to genomic instability

Question 13

Which gene is most commonly mutated across a wide variety of human cancers?

Accepted Answer

TP53

Question 14

A patient with colorectal cancer is found to have a mutation in the APC gene. Which pathway is most directly affected by this mutation?

Accepted Answer

Wnt signaling pathway

Question 15

Which of the following best explains why two patients with the same cancer type may respond differently to the same therapy?

Accepted Answer

Genetic heterogeneity leads to different mutation profiles and drug responses.

Question 16

A mutation in the KRAS gene results in continuous activation of downstream signaling pathways. Which cellular process is most directly affected?

Accepted Answer

Cell growth and proliferation

Question 17

Which of the following best describes the inheritance pattern of mitochondrial diseases?

Accepted Answer

Maternally inherited, affecting both sexes

Question 18

A patient with a BRCA1 mutation is at increased risk for breast and ovarian cancer. What is the primary cellular defect caused by this mutation?

Accepted Answer

Defective DNA repair of double-strand breaks

Question 19

Which of the following best explains why cancer is considered both a genetic and evolutionary disease?

Accepted Answer

Cancer cells accumulate somatic mutations and undergo natural selection for growth advantages.

Question 20

A new therapy uses nanoparticles to deliver chemotherapy drugs directly to tumor cells, minimizing side effects. Which field does this approach represent?

Accepted Answer

Nanomedicine

Genetic Markers, Cancer Biology, and Genetic Diseases: Study Guide

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