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Cell Cycle and Cancer

Investigation 3 – PreLab









This Investigation is designed to help you to answer the following Focus Question:

  • What is the relationship between the control of the cell cycle and cancer? 

Note: This question is located in your SDR at the beginning and end of the Investigation.


As a class, read the Background(s) in the Investigation. When finished, discuss the following concepts as a class:

  • Regulation of the cell cycle is very important. If cells divided at random, the organization of the tissue would be lost and the function of the organ would be affected.
  • If the gene that codes for the controlling protein is damaged or mutated, then a properly functioning protein cannot be produced.
  • If there is no production of the controlling proteins, the cells will go through the cell cycle and divide unregulated.
  • Each new (daughter) cell will inherit the mutated gene for this controlling protein because the cell receives an exact copy of the DNA in the original (parent) cell. This means that every daughter cell produced from the originally damaged cell will also divide continuously.
  • Cancer is defined as a group of diseases that involve the uncontrolled cell division of body cells.
  • Cancer begins when one normal body cell breaks free from normal controls of the cell cycle and begins to follow its own rate of cell division. This happens after damage to the cell’s DNA has occurred, which affects the production of the controlling protein.
  • All cells produced by this cell, and all cells from those daughter cells, will also follow a faster rate of cell division.
  • This process allows a tumor, made up of a mass of cells, to develop.
  • A tumor can invade normal tissue and therefore alter its overall organization and structure.
  • This disorganization leads to an inability of the tissue to function, which in turn means that the organ cannot function properly.
  • If a single cancerous cell breaks away from the tumor it can travel in the blood to other places throughout the body. At a new site, this single cancer cell will proliferate and form another tumor. This is called metastases and is how cancer spreads.
  • Lung cancer, called adenocarcinoma, is one of the leading causes of death in adults.
  • The primary cause of lung cancer is cigarette smoke. The chemicals in cigarette smoke are inhaled and absorbed by cells in the lung.
  • These toxins damage DNA. If the damage occurs on a gene that normally codes for a cell cycle controlling protein, cancer can develop. 
  • Breast cancer develops when a normal duct or lobule cell transforms into a cancerous cell that divides in an uncontrolled manner.
  • This transformation occurs after a mutation occurs in the gene that controls the production of a cell cycle controlling protein. 


The following list includes Key Terms that are introduced in the Investigation Background(s). They should be used, as appropriate, by teachers and students during everyday classroom discourse.

  • cancer
  • metastases
  • adenocarcinoma

Note: Definitions of these terms can be found on the Introduction page to the CELL.

Note: Additional words may be bolded within the Background(s). These words are not Key Terms and are strictly emphasized for exposure at this time.


  • Complete the Recall section in your SDR. 
  • How is cell division controlled?
  • What would happen if cells continued to divide without any controls of cell division? 
  • Play the video below. Remember to follow along with your SDR and make any notes that you think might be helpful.
  • After the video, divide into lab groups to discuss strategy for the lab. For example, you may assign certain group members to perform specific functions during the lab.

Note: The purpose of the video is to allow you to anticipate the laboratory experience you will soon encounter. You should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.

Note: Homework is posted below the video.


You should review the Investigation and video in preparation for the Lab.