Question 1

Which of the following best describes the role of histone proteins in eukaryotic cells?

Accepted Answer

They package DNA into nucleosomes, regulate gene expression, and protect DNA from damage.

Question 2

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

Accepted Answer

S phase

Question 3

A cell with 46 chromosomes undergoes mitosis. How many chromosomes will each daughter cell have after division?

Accepted Answer

46 chromosomes

Question 4

What is the function of the spindle assembly checkpoint (SAC) during mitosis?

Accepted Answer

It ensures that all chromosomes are properly attached to spindle fibers and under tension before anaphase begins.

Question 5

Which equation correctly represents the number of chromosomes in gametes compared to somatic cells?

Accepted Answer

$$n_{gamete} = \frac{1}{2} n_{somatic}$$

Question 6

Which structure is responsible for attaching spindle microtubules to chromosomes during mitosis?

Accepted Answer

Kinetochore

Question 7

A scientist observes a cell with condensed chromosomes aligned at the center of the cell. Which phase is the cell most likely in?

Accepted Answer

Metaphase

Question 8

Which of the following is NOT a function of cell division in multicellular organisms?

Accepted Answer

Production of energy

Question 9

What would happen if the spindle checkpoint failed and anaphase began before all chromosomes were properly attached?

Accepted Answer

Chromosome mis-segregation could occur, leading to conditions such as Down syndrome.

Question 10

Which of the following best describes the difference between mitosis and meiosis?

Accepted Answer

Mitosis produces genetically identical daughter cells, while meiosis produces nonidentical daughter cells with half the chromosome number.

Question 11

Which checkpoint is considered the most important for determining whether a cell will proceed through the cell cycle?

Accepted Answer

G1 checkpoint

Question 12

What is the role of MPF (maturation-promoting factor) in the cell cycle?

Accepted Answer

It triggers the cell’s passage past the G2 checkpoint into the M phase.

Question 13

Which of the following is a real-world example of an external factor influencing cell division?

Accepted Answer

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

Question 14

Cancer cells differ from normal cells in that they:

Accepted Answer

Do not respond normally to cell cycle control mechanisms and can divide indefinitely.

Question 15

Which of the following best describes the process of cytokinesis in animal cells?

Accepted Answer

Formation of a cleavage furrow by a contractile ring of microfilaments.

Question 16

If a cell does not receive a go-ahead signal at the G1 checkpoint, what happens?

Accepted Answer

It exits the cell cycle and enters a nondividing state called G0.

Question 17

Which of the following equations represents the phosphorylation reaction catalyzed by cyclin-dependent kinases (Cdks)?

Accepted Answer

$$	ext{Protein} + 	ext{ATP} ightarrow 	ext{Protein-P} + 	ext{ADP}$$

Question 18

Which of the following is NOT a type of spindle fiber found in the mitotic spindle?

Accepted Answer

Nucleosome microtubules

Question 19

A cell is observed to have a cleavage furrow forming. Which stage of cell division is it most likely undergoing?

Accepted Answer

Cytokinesis

Question 20

Which of the following statements about chromatin and chromosomes is correct?

Accepted Answer

Chromosomes are formed when chromatin condenses during cell division.

The Cell Cycle: Mechanisms and Regulation

Study Guide - Practice Questions