Question 1

Which of the following best describes the role of tumor suppressor genes in cancer development?

Accepted Answer

They prevent inappropriate cell behavior, and their loss of function can lead to cancer.

Question 2

A single point mutation in the Ras gene can lead to which of the following outcomes?

Accepted Answer

Ras protein cannot hydrolyze GTP, resulting in continuous cell signaling and proliferation.

Question 3

Which of the following statements about DNA methylation and gene expression is correct?

Accepted Answer

DNA hypermethylation typically compacts chromatin and silences gene expression.

Question 4

In the context of stem cells and cancer, what is the significance of cancer stem cells in tumor recurrence?

Accepted Answer

Cancer stem cells are resistant to treatment and can regenerate tumors even after most cells are destroyed.

Question 5

Which of the following best explains why epidemiological studies are important in cancer research?

Accepted Answer

They reveal patterns and environmental factors associated with cancer incidence in populations.

Question 6

The Ames test is used to determine if a substance is a mutagen. What is the key indicator of mutagenicity in this assay?

Accepted Answer

The substance increases the number of bacterial colonies able to grow without histidine.

Question 7

Which of the following scenarios describes the process of metastasis?

Accepted Answer

Cancer cells migrate to a distant site and successfully form a new tumor colony.

Question 8

What is the primary function of the p53 protein in the cell?

Accepted Answer

To suppress cell proliferation in response to cellular stress or DNA damage.

Question 9

Which of the following best describes the relationship between mutagens and carcinogens?

Accepted Answer

There is a strong correlation; substances that are mutagenic are often carcinogenic.

Question 10

A patient inherits one defective copy of the APC gene, a tumor suppressor. What is the likely consequence?

Accepted Answer

They are at increased risk for developing multiple benign polyps in the colon.

Question 11

Which of the following is a property of embryonic stem cells but NOT adult stem cells?

Accepted Answer

Ability to differentiate into all embryonic cell types except extraembryonic tissue.

Question 12

If a receptor tyrosine kinase (RTK) is mutated so that it is constitutively active, what is the likely cellular outcome?

Accepted Answer

The cell will continuously signal for proliferation, even without growth factor.

Question 13

Which of the following best explains why quitting smoking reduces the risk of dying from lung cancer over time?

Accepted Answer

Removing the mutagenic agent reduces further accumulation of mutations, lowering cancer risk.

Question 14

Which of the following is a correct statement about the multi-step nature of cancer development?

Accepted Answer

Cancer development involves multiple genetic and epigenetic changes over many years.

Question 15

Which of the following best describes the effect of DNA hypomethylation in cancer cells?

Accepted Answer

It can increase chromatin accessibility, potentially activating oncogenes.

Question 16

A scientist observes that a chemical requires only $$10^{-2}$$ micrograms to produce 100 colonies per plate in the Ames test. What does this indicate about the chemical?

Accepted Answer

It has high mutagenic potency.

Question 17

Which of the following is a possible outcome if both copies of a tumor suppressor gene are silenced by hypermethylation?

Accepted Answer

The cell loses a critical defense against inappropriate proliferation, increasing cancer risk.

Question 18

Which of the following best describes the role of p53 in response to DNA damage?

Accepted Answer

p53 accumulates and can induce cell cycle arrest, DNA repair, or apoptosis.

Question 19

Which of the following is true regarding the difference between oncogenes and tumor suppressor genes?

Accepted Answer

Tumor suppressor genes require loss of both alleles for loss of function.

BIO 102 Week 8 Cancer Part 2 A

Guida di studio - Domande di pratica

Study guide - Flashcard