AP BIOLOGY

Detailed explanation-1: -Cell cycle checkpoints are surveillance mechanisms that monitor the order, integrity, and fidelity of the major events of the cell cycle. These include growth to the appropriate cell size, the replication and integrity of the chromosomes, and their accurate segregation at mitosis.

Detailed explanation-2: -DNA damage checkpoints are essential control points in the cell cycle ensuring effective damage repair. The loss of checkpoint functions leads to loss of genomic integrity and allows accumulation of genetic damage in the daughter cells. Checkpoint deficiency is one of the main causes of DNA aberrations in cancer.

Detailed explanation-3: -Cell cycle is the fundamental process by which a cell matures, synthesises DNA and divides to form daughter cells. Somatic cells divide regularly. All multicellular organisms use cell division for growth, maintenance and repair of cells and tissues. Unicellular organisms use this process to reproduce.

Detailed explanation-4: -If the checkpoint mechanisms detect problems with the DNA, the cell cycle is halted, and the cell attempts to either complete DNA replication or repair the damaged DNA. If the damage is irreparable, the cell may undergo apoptosis, or programmed cell death 2.

Detailed explanation-5: -To ensure that each phase of the cell cycle is carried out correctly, essential steps are followed by a checkpoint. It is a control mechanism where certain conditions must be met before the cell can progress to the next step.