Question 1

Which of the following best describes the main difference between mitosis and meiosis in terms of genetic material in the resulting cells?

Accepted Answer

Mitosis produces genetically identical daughter cells, while meiosis produces daughter cells with half the hereditary material as the parent cell.

Question 2

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

Accepted Answer

S phase

Question 3

What is the role of cohesins during mitosis?

Accepted Answer

They hold sister chromatids together along their entire length until anaphase.

Question 4

Which structure is responsible for organizing the spindle apparatus during mitosis?

Accepted Answer

Centrosome

Question 5

A mutation causes the p53 protein to become nonfunctional in a cell. What is the most likely consequence?

Accepted Answer

The cell may divide uncontrollably, increasing the risk of cancer.

Question 6

Which of the following events occurs during anaphase of mitosis?

Accepted Answer

Sister chromatids are pulled toward opposite poles of the cell.

Question 7

What is the function of the MPF (M phase-promoting factor) cyclin-dependent kinase (Cdk) complex?

Accepted Answer

It phosphorylates target proteins to initiate mitosis.

Question 8

Which checkpoint ensures that all chromosomes are properly attached to the spindle before sister chromatids separate?

Accepted Answer

Metaphase-to-anaphase checkpoint

Question 9

In animal cells, what structure is responsible for physically dividing the cytoplasm during cytokinesis?

Accepted Answer

Cleavage furrow formed by actin and myosin filaments

Question 10

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

Accepted Answer

They bypass cell-cycle checkpoints due to defects in regulatory proteins.

Question 11

A researcher observes that a cell has replicated its DNA but cannot enter mitosis. Which checkpoint is most likely preventing progression?

Accepted Answer

$$G_2$$ checkpoint

Question 12

Which of the following is true about sister chromatids?

Accepted Answer

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

Question 13

What is the role of growth factors in the regulation of the cell cycle?

Accepted Answer

They stimulate production of cyclins that help cells pass the $$G_1$$ checkpoint.

Question 14

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

Accepted Answer

It is similar to M phase in eukaryotes but does not involve mitosis.

Question 15

If a cell's Rb protein is defective and cannot bind E2F, what is the likely outcome?

Accepted Answer

E2F will continuously activate genes for S phase, leading to uncontrolled cell division.

Question 16

Which of the following equations correctly represents the phosphorylation reaction catalyzed by a protein kinase?

Accepted Answer

$$\mathrm{Protein} + \mathrm{ATP} \rightarrow \mathrm{Protein{-}P} + \mathrm{ADP}$$

Question 17

Which of the following is a direct result of negative feedback in the regulation of MPF activity?

Accepted Answer

An enzyme complex marks cyclin for destruction, leading to MPF deactivation.

Question 18

A cell is observed to have a ring of actin and myosin filaments contracting at its equator. What process is this cell undergoing?

Accepted Answer

Cytokinesis in an animal cell

Question 19

Which of the following best explains why cells spend most of their time in interphase?

Accepted Answer

Cells are growing, performing specialized functions, and preparing for division during interphase.

Question 20

Which of the following is a property of malignant tumors but not benign tumors?

Accepted Answer

They can metastasize and invade other tissues.

The Cell Cycle: Structure, Phases, and Mechanisms of Cellular Replication

Study Guide - Practice Questions