Science: The Cell Cycle and Cancer Worksheet

Question 1

List the main stages of the eukaryotic cell cycle in order, including interphase and the stage when the cell splits.

Accepted Answer

The main stages of the eukaryotic cell cycle are interphase, mitosis, and cytokinesis. Interphase includes G1, S, and G2, mitosis divides the nucleus, and cytokinesis divides the cytoplasm to form two daughter cells.

Question 2

Describe what happens during the S phase of interphase.

Accepted Answer

During the S phase, the cell replicates its DNA. This produces a complete copy of the genetic material so each daughter cell can receive the same set of chromosomes after division.

Question 3

Explain the purpose of a cell cycle checkpoint.

Accepted Answer

A cell cycle checkpoint helps the cell decide whether it is safe to continue dividing. It checks conditions such as cell size, DNA accuracy, and whether chromosomes are properly prepared so damaged or unready cells do not keep progressing.

Question 4

What is the difference between a proto-oncogene and an oncogene?

Accepted Answer

A proto-oncogene is a normal gene that helps regulate cell growth and division. An oncogene is a mutated or overactive version of that gene that can push cells to divide too often and contribute to cancer.

Question 5

Tumor suppressor genes are often compared to brakes in a car. Explain this comparison.

Accepted Answer

Tumor suppressor genes are compared to brakes because they slow down or stop cell division when necessary. If these genes are damaged or lost, the cell may keep dividing without proper control, which can increase the risk of cancer.

Question 6

A mutation prevents a cell from repairing damaged DNA at a checkpoint. Explain how this can increase the chance of cancer.

Accepted Answer

If a cell cannot repair damaged DNA at a checkpoint, it may continue dividing with mutations still present. Over time, additional mutations can build up in genes that control growth and division, increasing the chance that the cell becomes cancerous.

Question 7

Define cancer in terms of cell cycle regulation.

Accepted Answer

Cancer is a disease in which cells lose normal control of the cell cycle and divide uncontrollably. These abnormal cells can form tumors, invade nearby tissues, and sometimes spread to other parts of the body.

Question 8

How is metastasis different from the formation of a primary tumor?

Accepted Answer

A primary tumor forms at the original site where abnormal cells first begin growing. Metastasis occurs when cancer cells break away, travel through the blood or lymph system, and form new tumors in other parts of the body.

Question 9

Why do rapidly dividing cancer cells often respond to chemotherapy, and why can healthy cells also be harmed?

Accepted Answer

Chemotherapy often targets cells that divide quickly, so it can be effective against many cancer cells. However, some healthy cells also divide rapidly, such as cells in hair follicles, the digestive tract, and bone marrow, so they can be damaged as well.

Question 10

Compare benign tumors and malignant tumors.

Accepted Answer

Benign tumors are noncancerous growths that usually remain localized and do not invade nearby tissues. Malignant tumors are cancerous, can invade surrounding tissues, and may spread to distant parts of the body through metastasis.

Question 11

A scientist finds that a cell has ignored signals to stop dividing and has activated genes that promote constant growth. What does this suggest about the cell, and why?

Accepted Answer

This suggests that the cell may be developing into or already functioning as a cancer cell. Ignoring stop signals and activating constant growth pathways are signs that normal regulation of the cell cycle has been disrupted.

Question 12

Explain why studying the cell cycle helps scientists develop cancer treatments.

Accepted Answer

Studying the cell cycle helps scientists identify which molecules and checkpoints control cell division. This knowledge allows researchers to design treatments that target specific failures in cancer cells, such as overactive growth signals or damaged checkpoint systems.

Science: The Cell Cycle and Cancer

Science: The Cell Cycle and Cancer

More Biology Worksheets

More Grade 9-12 Worksheets