Discuss "cancer" in terms of cell cycle regulation and the health of both humans and animals?
Cancer is, by definition, a type of disease in which cells are growing out of control and basically unregulated by the normal cell cycle. Normally cells die and are cycled out through various waste systems according to senescence and the telomeres, the small pieces of DNA on the end of each chromosome that dictate how long a cell will reproduce, eventually is worn out. It is believed that an enzyme called telomerase is present in large enough quantities in cancerous cells to allow them to reproduce indefinitely.
This unchecked reproduction will eventually lead to massive health problems and death, particularly if the cancer cells are the type to metastasize and spread throughout the body.