Question 1

During which phase of the cell cycle does DNA replication occur, resulting in the formation of sister chromatids?

Accepted Answer

S phase

Question 2

Which structure is responsible for holding sister chromatids together after DNA replication?

Accepted Answer

Centromere

Question 3

What is the primary function of the spindle fibers during mitosis?

Accepted Answer

To attach to the centromere and pull sister chromatids apart

Question 4

Which checkpoint in the cell cycle ensures that DNA is not damaged before replication begins?

Accepted Answer

G1/S checkpoint

Question 5

If a cell fails to pass the G1 checkpoint, what is its likely fate?

Accepted Answer

It will enter the G0 phase and stop dividing

Question 6

Which equation best represents the chromosome number change during mitosis in a diploid cell?

Accepted Answer

$$2n \rightarrow 2n$$

Question 7

What distinguishes cytokinesis in plant cells from animal cells?

Accepted Answer

Plant cells form a cell plate, while animal cells form a cleavage furrow

Question 8

Which protein complex triggers a cell’s passage past the G2 checkpoint into the M phase?

Accepted Answer

MPF (maturation-promoting factor)

Question 9

Cancer cells often lose which two types of regulation that normal cells exhibit?

Accepted Answer

Density-dependent inhibition and anchorage dependence

Question 10

During which stage of mitosis are chromosomes most condensed and aligned at the cell’s center?

Accepted Answer

Metaphase

Question 11

What is the role of the enzyme separase during mitosis?

Accepted Answer

It cleaves cohesins to allow sister chromatids to separate

Question 12

Which phase of mitosis is characterized by the reformation of the nuclear envelope and uncoiling of chromosomes?

Accepted Answer

Telophase

Question 13

A cell is observed to have chromosomes at opposite poles and a reforming nuclear envelope. Which phase is it in?

Accepted Answer

Telophase

Question 14

Which checkpoint ensures that all chromosomes are properly attached to spindle fibers before proceeding to anaphase?

Accepted Answer

Spindle assembly checkpoint

Question 15

What is the result of mitosis followed by cytokinesis in a typical somatic cell?

Accepted Answer

Two genetically identical daughter cells

Question 16

Which external factor is known to stimulate cell division in wound healing?

Accepted Answer

Platelet-derived growth factor (PDGF)

Question 17

A scientist observes a cell that continues to divide even when crowded and unattached to a surface. What is the most likely explanation?

Accepted Answer

The cell is a cancer cell lacking proper cell cycle regulation

Question 18

Which process describes the conversion of a normal cell into a cancerous cell?

Accepted Answer

Transformation

Question 19

If a cell has 8 chromosomes at the start of mitosis, how many chromosomes will each daughter cell have after mitosis and cytokinesis?

Accepted Answer

$$8$$

Question 20

Which of the following best describes the relationship between cyclins and cyclin-dependent kinases (Cdks) in cell cycle regulation?

Accepted Answer

Cyclins bind to Cdks, activating them to regulate cell cycle progression

The Cell Cycle: Mechanisms and Regulation

Study Guide - Practice Questions