AP BIOLOGY

Detailed explanation-1: -Cancer is unchecked cell growth. Mutations in genes can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as cell cycle arrest or programmed cell death. As a mass of cancerous cells grows, it can develop into a tumor.

Detailed explanation-2: -Unlike normal cells, cancer cells don’t stop growing and dividing when there are enough of them. So the cells keep doubling, forming a lump (tumour) that grows in size.

Detailed explanation-3: -Normal cells follow a typical cycle: They grow, divide and die. Cancer cells, on the other hand, don’t follow this cycle. Instead of dying, they multiply and continue to reproduce other abnormal cells. These cells can invade body parts, such as the breast, liver, lungs and pancreas.

Detailed explanation-4: -Cancer is essentially a disease of mitosis-the normal ‘checkpoints’ regulating mitosis are ignored or overridden by the cancer cell. Cancer begins when a single cell is transformed, or converted from a normal cell to a cancer cell.

Detailed explanation-5: -There have to be about 6 different mutations before a normal cell turns into a cancer cell. Mutations in particular genes may mean that: a cell starts making too many proteins that trigger a cell to divide. a cell stops making proteins that normally tell a cell to stop dividing.