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, and spindle fibers attached to kinetochores. Which phase is this cell in?

Accepted Answer

Metaphase

Question 4

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

Accepted Answer

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

Question 5

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

Accepted Answer

M checkpoint

Question 6

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

Accepted Answer

They phosphorylate target proteins to regulate cell cycle progression.

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.

Question 8

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

Accepted Answer

$$2n \rightarrow 4n \rightarrow 2n$$

Question 9

Which of the following is NOT a function of tumor-suppressor proteins?

Accepted Answer

Stimulating cell division

Question 10

Binary fission in bacteria differs from mitosis in eukaryotes in that:

Accepted Answer

Binary fission does not involve a mitotic spindle or nuclear envelope breakdown.

Question 11

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

Accepted Answer

They ignore cell cycle checkpoints and may produce their own growth factors.

Question 12

A proto-oncogene can become an oncogene by all of the following EXCEPT:

Accepted Answer

Loss of function mutation

Question 13

During which phase of mitosis do the sister chromatids become individual chromosomes?

Accepted Answer

Anaphase

Question 14

Which of the following statements about the G1 checkpoint is correct?

Accepted Answer

It determines whether the cell will proceed to DNA synthesis or enter G0.

Question 15

If a cell has 8 chromosomes at the start of G1, how many chromatids will it have after S phase?

Accepted Answer

16

Question 16

Which of the following best describes the role of cohesin proteins during mitosis?

Accepted Answer

They hold sister chromatids together until anaphase.

Question 17

A patient inherits a mutant allele of a tumor-suppressor gene. What is the most likely consequence?

Accepted Answer

Increased risk of developing cancer due to reduced inhibition of cell division.

Question 18

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 19

Which of the following best describes the relationship between chromatin, chromosomes, and chromatids?

Accepted Answer

Chromatin is condensed into chromosomes, which consist of two sister chromatids after DNA replication.

Question 20

Which of the following equations represents the number of DNA molecules in a human somatic cell during metaphase of mitosis?

Accepted Answer

$$2n = 46$$ chromosomes, $$92$$ DNA molecules

The Cell Cycle and Molecular Biology of Cancer: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard