Question 1

Which of the following best describes the role of tumor suppressor genes in the cell cycle?

Accepted Answer

They encode proteins that halt cell division.

Question 2

A mutation in a proto-oncogene most likely results in which of the following outcomes?

Accepted Answer

Uncontrolled cell division due to the formation of an oncogene.

Question 3

Which experimental result from Griffith’s experiment demonstrated that genetic information could be transferred between bacteria?

Accepted Answer

Mice injected with a mixture of heat-killed pathogenic and live harmless bacteria died.

Question 4

Why was it important for Avery, MacLeod, and McCarty to treat the bacterial extract with enzymes that destroy DNA, RNA, or protein separately?

Accepted Answer

To determine which molecule was responsible for transformation.

Question 5

Which of the following conclusions is supported by Avery, MacLeod, and McCarty’s experiment?

Accepted Answer

DNA is required for transformation of harmless bacteria to pathogenic bacteria.

Question 6

Which control group in Griffith’s experiment was necessary to confirm that the harmless bacteria were truly non-pathogenic?

Accepted Answer

Mice injected with live harmless bacteria.

Question 7

Cancer typically arises due to:

Accepted Answer

Multiple mutations in genes controlling cell division and DNA repair.

Question 8

Which phase of the cell cycle is characterized by DNA synthesis?

Accepted Answer

$$S$$

Question 9

What is the primary function of cyclin-dependent kinases (Cdks) in the cell cycle?

Accepted Answer

To catalyze phosphorylation of other proteins to start M phase.

Question 10

A scientist removes all DNA from a bacterial extract before mixing it with harmless bacteria. What is the expected outcome?

Accepted Answer

The harmless bacteria will remain harmless.

Question 11

Which of the following best explains why understanding the structure of DNA was essential for understanding its function?

Accepted Answer

The double helix structure suggested a mechanism for replication and information storage.

Question 12

Which of the following is NOT a function of proteins encoded by tumor suppressor genes?

Accepted Answer

Promoting uncontrolled cell growth.

Question 13

If a cell accumulates mutations in both a proto-oncogene and a tumor suppressor gene, what is the most likely result?

Accepted Answer

The cell may begin to divide uncontrollably, increasing cancer risk.

Question 14

Which of the following statements about the cell cycle is correct?

Accepted Answer

The cell cycle is regulated by specific proteins, including cyclins and Cdks.

Question 15

A patient is diagnosed with cancer. Which of the following is most likely true about the patient’s cells?

Accepted Answer

They have mutations in multiple genes involved in cell cycle regulation.

Question 16

Which of the following best describes the outcome when the M phase-promoting factor (MPF) is activated?

Accepted Answer

The cell initiates mitosis.

Question 17

Which of the following is a real-world example of a gene mutation leading to cancer?

Accepted Answer

A mutation in the BRCA1 gene increasing breast cancer risk.

Question 18

Which of the following is a key reason why scientists use control groups in experiments like Griffith’s?

Accepted Answer

To ensure that observed effects are due to the experimental variable.

Question 19

Which of the following best explains why DNA, and not protein, is the hereditary material?

Accepted Answer

DNA is required for transformation, and its removal prevents the transfer of genetic traits.

Question 20

A scientist hypothesizes that a new molecule is responsible for inheritance. Which experimental approach would best test this hypothesis?

Accepted Answer

Remove the molecule from a cell extract and test if transformation still occurs.

DNA, Genes, Cell Cycle Regulation, and Cancer: Synthesis, Repair, and Experimental Evidence

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