AP BIOLOGY

Detailed explanation-1: -Cancerous growth could result if a normal dividing cell should suffer a somatic mutation that disrupts normal cell cycle control. Think an over-expression of cdk for example. Alternatively, imagine cyclin levels in daughter cells that never drop; such cells would never stop cycling.

Detailed explanation-2: -Proto-oncogenes positively regulate the cell cycle. Mutations may cause proto-oncogenes to become oncogenes, disrupting normal cell division and causing cancers to form.

Detailed explanation-3: -Uncontrolled Cell Growth: Cancer Cancer is a disease of the cell cycle. Cancer cells do not respond to the signals and safeguards that are in place. Because cancer cells don’t respond appropriately, they grow uncontrollably and can eventually damage the tissues around them.

Detailed explanation-4: -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-5: -DNA Synthesis (S phase) In many cancer cells the number of chromosomes is altered so that there are either too many or too few chromosomes in the cells. These cells are said to be aneuploid. Errors may occur during the DNA replication resulting in mutations and possibly the development of cancer.