Question

The carefully regulated activation of signaling pathways is essential for proper cell function, but regulating the termination of a signal response is not important. True O False

Answer 1

1. False Signalling pathways regulation is essential for proper cell function but termination of a signal response regulation is also that important. For example- in the normal cell cycle, the termination is regulation of Rb protein that mask E2F protein and prevents undesirable cell proliferation.

2. False. In the case of familial adenomatous polyposis, affected individuals develop colon cancer early in life because they have inherited one non-functional gene. The defect in other gene is due to environmental hit.

Because APC gene is produced by tumor suppressor genes. The hit in both gene is necessary for disease otherwise it will be carrier.