AP BIOLOGY

Detailed explanation-1: -Cancer is basically a disease of uncontrolled cell division. Its development and progression are usually linked to a series of changes in the activity of cell cycle regulators.

Detailed explanation-2: -Cancer is the result of unchecked cell division caused by a breakdown of the mechanisms regulating 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. Faulty instructions lead to a protein that does not function as it should.

Detailed explanation-3: -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. These changes are also called genetic changes.

Detailed explanation-4: -Superficially, the connection between the cell cycle and cancer is obvious: cell cycle machinery controls cell proliferation, and cancer is a disease of inappropriate cell proliferation. Fundamentally, all cancers permit the existence of too many cells.

Detailed explanation-5: -Cancers, however, occur due to an alteration of a normal biological process-cell division. Cells that progress through the cell cycle unchecked may eventually form malignant tumors, where masses of cells grow and divide uncontrollably, then develop the ability to spread and migrate throughout the body.