NEET BIOLOGY

Detailed explanation-1: -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-2: -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-3: -Activation of meiotic genes in somatic cells contribute to properties of tumor formation and progression. The re-expression of meiotic genes in somatic cancer cells is responsible for driving some of the hallmarks of cancers (shown in bold).

Detailed explanation-4: -In summary, cancer cells have defects in normal cellular functions that allow them to divide, invade the surrounding tissue, and spread by way of vascular and/or lymphatic systems. These defects are the result of gene mutations sometimes caused by infectious viruses.

Detailed explanation-5: -Cells grow then divide by mitosis only when we need new ones. This is when we’re growing or need to replace old or damaged cells. When a cell becomes cancerous, it begins to grow and divide uncontrollably. New cells are produced even if the body does not need them.