Question 1

Which of the following best describes the role of the mitotic spindle during mitosis?

Accepted Answer

It organizes and separates chromosomes by attaching to kinetochores and pulling sister chromatids apart.

Question 2

During which phase of the cell cycle does DNA replication occur?

Accepted Answer

S phase

Question 3

A cell is observed with condensed chromosomes aligned at the center of the cell, each attached to spindle fibers from opposite poles. Which phase is this cell in?

Accepted Answer

Metaphase

Question 4

Which of the following statements about sister chromatids is correct?

Accepted Answer

They are identical copies of a chromosome joined at the centromere.

Question 5

What is the primary difference between cytokinesis in plant and animal cells?

Accepted Answer

Animal cells form a cleavage furrow, while plant cells form a cell plate.

Question 6

Which checkpoint in the cell cycle ensures that all chromosomes are properly attached to the spindle before anaphase begins?

Accepted Answer

M checkpoint

Question 7

A mutation in the p53 gene can lead to cancer because:

Accepted Answer

p53 normally suppresses the cell cycle in response to DNA damage, preventing the propagation of mutations.

Question 8

Which of the following best explains why cancer cells can divide uncontrollably?

Accepted Answer

They often have mutations in proto-oncogenes and tumor-suppressor genes, disrupting normal cell cycle control.

Question 9

Which of the following equations correctly represents the change in chromosome number during mitosis in a human somatic cell?

Accepted Answer

$$2n \rightarrow 2n$$

Question 10

Which of the following is a function of tumor-suppressor proteins?

Accepted Answer

Repairing damaged DNA and inhibiting the cell cycle

Question 11

A researcher observes a cell with two nuclei forming and chromosomes beginning to uncoil. Which phase is this cell most likely in?

Accepted Answer

Telophase

Question 12

Which of the following best describes the process of binary fission in bacteria?

Accepted Answer

The chromosome replicates, and the cell divides as the plasma membrane pinches inward.

Question 13

Which of the following is true regarding cyclin-dependent kinases (Cdks)?

Accepted Answer

Cdks are active only when bound to a cyclin.

Question 14

A cell is exposed to a chemical that prevents the breakdown of cohesin proteins. What is the most likely result during mitosis?

Accepted Answer

Sister chromatids will not separate during anaphase.

Question 15

Which of the following genetic changes can convert a proto-oncogene into an oncogene?

Accepted Answer

A mutation that increases the amount or activity of the protein product

Question 16

Which of the following best explains why individuals with inherited mutations in tumor-suppressor genes are at higher risk for cancer?

Accepted Answer

They are born with one defective copy, so only one additional mutation is needed to lose tumor suppression.

Question 17

Which of the following is a real-life example of a growth factor influencing the cell cycle?

Accepted Answer

Platelet-derived growth factor (PDGF) stimulating fibroblast division during wound healing

Question 18

Which of the following best describes the role of MPF (maturation-promoting factor) in the cell cycle?

Accepted Answer

MPF triggers the cell's passage past the G2 checkpoint into the M phase.

Question 19

A cell is observed to have exited the cell cycle and is not dividing. Which phase is it most likely in?

Accepted Answer

G0 phase

Question 20

Which of the following best explains why the incidence of cancer increases with age?

Accepted Answer

Multiple mutations are generally needed for full-fledged cancer, and these accumulate over time.

The Cell Cycle and Molecular Biology of Cancer: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard