PATHOLOGY

Detailed explanation-1: -At the heart of the cell-cycle control system is a family of protein kinases known as cyclin-dependent kinases (Cdks). The activity of these kinases rises and falls as the cell progresses through the cycle.

Detailed explanation-2: -Tumor suppressor genes, on the other hand, restrict cell cycle progression.

Detailed explanation-3: -As the activity of Cdk5 was mainly detected in postmitotic neurons, it has been considered that Cdk5 is not involved in cell cycle regulation.

Detailed explanation-4: -These proteins are created at different times in the cell cycle, and these proteins are capable of binding to cyclin-dependent kinases, which then allow the Cdks to activate certain proteins that are necessary for the next stage of the cell cycle.