IB Biology HL 2.1.15 Cell cycle control by cyclins Question Bank

a. cell cycle is a sequence of stages / cell cycle is $\mathrm{G}_{1}, \mathrm{~S}, \mathrm{G}_{2}$ and mitosis

b. (control of the cell cycle) by cyclins/cyclin

c. levels of cyclins rise (and fall)/fluctuate during the cell cycle/surge at different times/have to reach a certain concentration

d. conditions inside as well as outside the cell affect regulation

e. four cyclins/different cyclins to enter different stages of/events in the cell cycle / cyclins regulate the sequence/timing of the cell cycle/cyclins trigger the next stages

f. cyclin-dependent kinases / cyclins bind to kinases and activate them

g. kinases phosphorylate other proteins

h. phosphorylated proteins perform specific functions in the cell cycle

The idea of different cyclins acting at different phases must be clear.

4 max