Question

1. how do cyclins \signal\ a cell to move to the next stage of the cycle?

Explanation:

Cyclins bind to cyclin - dependent kinases (CDKs). This binding activates CDKs, which then phosphorylate target proteins involved in the cell - cycle. The phosphorylation of these proteins triggers a series of events that allow the cell to progress to the next stage of the cell cycle.

Answer:

Cyclins bind to and activate cyclin - dependent kinases (CDKs), which phosphorylate target proteins to trigger cell - cycle progression.