10-3 Regulating the Cell Cycle

Cells divide at different rates, depending on the cell type

--Nerve and muscle cells usually stop dividing once developed
--Skin cells divide frequently as skin is being replaced constantly

What Controls Cell Division?

Cell cycle regulators
Internal regulators
External regulators


When control of the cell cycle fails, cells begin to divide uncontrollably, resulting in masses and failure of the cells to perform their normal functions. This condition is called cancer.


Check out this game over the regulation of the Cell Cycle at Nobelprize.org

Check out this Animation on the Control of the Cell Cycle


Vaccines against cancer?

Gardasil is a vaccine that protects against HPV and can therefore protect females from certain kinds of cervical cancer.  This vaccine must be administered at a very young age before sexual activity.  Some states want to require this vaccine for all young girls.

Do you think the government should
require this vaccine?


Cancer = uncontrolled cell growth

Takes over the cell cycle

Causes can be environmental, genetic, viruses

*Viruses such as HPV, also called human papillomavirus are known to be linked to cervical cancer.



Unspecialized cells that have the potential to differentiate (to become any type of cell)

They can be found in

Human embryos
Some adult cells
Cord blood

Potential Uses for Stem Cells

Repair injuries of the brain and spinal cord
Cure some diseases (diabetes)
Replace organs (liver tissue, heart valves)