AP BIOLOGY

Detailed explanation-1: -This is called metastasis. Cancer is a disease caused when cells divide uncontrollably and spread into surrounding tissues. Cancer is caused by changes to DNA. Most cancer-causing DNA changes occur in sections of DNA called genes.

Detailed explanation-2: -Rather than responding appropriately to the signals that control normal cell behavior, cancer cells grow and divide in an uncontrolled manner, invading normal tissues and organs and eventually spreading throughout the body.

Detailed explanation-3: -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-4: -Disruption of normal regulation of the cell cycle can lead to diseases such as cancer. When the cell cycle proceeds without control, cells can divide without order and accumulate genetic errors that can lead to a cancerous tumor .

Detailed explanation-5: -Cancer is the result of unchecked cell division caused by a breakdown of the mechanisms that regulate the cell cycle. The loss of control begins with a change in the DNA sequence of a gene that codes for one of the regulatory molecules.