Dna, Dna replication, and cell division (mitosis and Meiosis)

Cancer

Key ConceptCell division out of control means cancer.Programmed cell death is a necessary process in living organisms because it makes room for new cells and eliminates broken cells.

The Cell Cycle and CancerThe Cell Cycle

Cytokinesis123

3Print the document The Cell Cycle and Cancer from the website. Answer the questions by using the narrated lecture notes to help you!

There are several factors that regulate the cell cycle and assure a cell divides correctly.Before a cell divides, the DNA is checked to make sure it has replicated correctly. If DNA does not copy itself correctly, a gene mutation occurs.

Chemical Signals tell a cell when to start and stop dividing.

Neighboring cells communicate with dividing cells to regulate their growth also.

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Out-of-control cell division caused by DNA mutations can fuel cancer.

Cancer is a disease of the cell cycle. Some of the bodys cells divide uncontrollably and tumors form Tumors in LiverTumor in Colon

6DNA mutations disrupt the cell cycle. Mutations may be caused by:

1. radiation 2. smoking 3. Pollutants 4. chemicals 5. viruses

7While normal cells will stop dividing if there is a mutation in the DNA (and even die), cancer cells will continue to divide with mutation.

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Due to DNA mutations, cancer cells ignore the chemical signals that start and stop the cell cycle.

This prevents cancer cells from communicating with neighboring cells. Cells continue to grow and form tumors.

Skin cancer Developing tumor

9SUMMARYNormal Cell Division

DNA is replicated properly.2. Chemical signals start and stop the cell cycle.3. Cells communicate with each other so they dont divide excessively and become overcrowded.Cancer Cells

Mutations occur in the DNA when it is replicated.2. Chemical signals that start and stop the cell cycle are ignored.3. Cells do not communicate with each other and tumors form.

10Treating CancersCancer treatments include drugs that can stop cancer cells from dividing.Now scientists have for the first time reversed the process of cell division, a breakthrough that could eventually lead to treatments for cancer and other disorders.

11The Check for this section is handing in the questions The Cell Cycle and Cancer that you printed off the website at home.