NEET BIOLOGY

Detailed explanation-1: -Unlike normal genes, oncogenes cannot be turned off, so they cause uncontrolled cell growth. In normal cells, tumor suppressor genes prevent cancer by slowing or stopping cell growth. DNA changes that inactivate tumor suppressor genes can lead to uncontrolled cell growth and cancer.

Detailed explanation-2: -Cancer is unchecked cell growth. Mutations in genes can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as cell cycle arrest or programmed cell death.

Detailed explanation-3: -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-4: -Study finds that high levels of a growth factor increases risk for several cancers. A study of almost 400, 000 British participants has identified a new link between raised levels of the growth factor IGF-1 and increased thyroid cancer risk and has confirmed associations with breast, prostate and colorectal cancer.

Detailed explanation-5: -An abnormal mass of tissue that forms when cells grow and divide more than they should or do not die when they should. Tumors may be benign (not cancer) or malignant (cancer). Benign tumors may grow large but do not spread into, or invade, nearby tissues or other parts of the body.