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, and what is the main outcome of this phase?

Accepted Answer

S phase; the cell synthesizes a complete copy of its DNA.

Question 3

A scientist observes a cell with chromosomes aligned at the center of the cell, attached to spindle fibers. Which phase is this cell in?

Accepted Answer

Metaphase

Question 4

Which checkpoint in the cell cycle is primarily responsible for ensuring that all chromosomes are properly attached to the spindle before separation?

Accepted Answer

M (metaphase) checkpoint

Question 5

What is the main difference between binary fission in prokaryotes and mitosis in eukaryotes?

Accepted Answer

Binary fission does not involve a nucleus, while mitosis involves the division of the nucleus.

Question 6

A mutation in a proto-oncogene can lead to cancer by which mechanism?

Accepted Answer

By promoting unregulated cell division, turning it into an oncogene.

Question 7

Which of the following best describes the function of tumor-suppressor genes?

Accepted Answer

They inhibit cell division, repair DNA errors, or induce apoptosis.

Question 8

In plant cells, cytokinesis is accomplished by the formation of which structure?

Accepted Answer

Cell plate

Question 9

If a cell does not receive a go-ahead signal at the G1 checkpoint, what is the most likely outcome?

Accepted Answer

The cell will exit the cell cycle and enter the G0 phase.

Question 10

Which of the following is true about sister chromatids?

Accepted Answer

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

Question 11

A patient is diagnosed with a malignant tumor. What characteristic distinguishes this tumor from a benign tumor?

Accepted Answer

It can metastasize to other organs.

Question 12

Which of the following events occurs during prophase of mitosis?

Accepted Answer

Chromatin condenses into visible chromosomes and the nucleolus disappears.

Question 13

What is the primary function of kinetochores during mitosis?

Accepted Answer

To attach spindle microtubules to chromosomes for movement.

Question 14

Which phase of the cell cycle is characterized by cell growth and preparation for DNA synthesis?

Accepted Answer

G1 phase

Question 15

A cell is observed with two nuclei forming and chromosomes decondensing. Which phase is this cell most likely in?

Accepted Answer

Telophase

Question 16

Which of the following best explains why multicellular organisms need cell division?

Accepted Answer

For development, growth, repair, and renewal of tissues.

Question 17

If a mutation disables a cell's tumor-suppressor gene, what is the most likely consequence?

Accepted Answer

The cell may divide uncontrollably, increasing cancer risk.

Question 18

Which of the following is a correct sequence of events during mitosis?

Accepted Answer

Prophase → Metaphase → Anaphase → Telophase

Question 19

Which structure is responsible for holding sister chromatids together until anaphase?

Accepted Answer

Centromere

Question 20

A researcher observes a cell with a visible cleavage furrow. What process is occurring?

Accepted Answer

Cytokinesis in an animal cell

The Cell Cycle and Mitosis: Structure, Function, and Regulation

Study Guide - Practice Questions