A cyclin called cyclin E forms a complex with a cyclin-dependent kinase called Cdk 2. This complex is important for the progression of the cell from G1 into the S phase of the cell cycle. Which of the following statements is most likely to be correct?

a. The amount of cyclin E is greatest during the S phase.

b. The amount of Cdk 2 is greater during G1 compared to the S phase.

c. The amount of cyclin E is highest during G1.

d. The amount of Cdk 2 is greatest during G1.

e. The activity of the cyclin E/Cdk 2 complex is highest during G2.

The amount of cyclin E is highest during G1

Explanation:

Cyclin and cdks acts as the regulators of the each step of the cell cycle. The level of these regulators determine the progression of the cell cycle. Different cyclins are cyclin E, cyclin D and cyclin A.

The interaction of cyclin E with cdk2 is important for cell to enter in G1 into the S phase of the cell cycle. The amount of cyclin E is high in the G1 phase and its amount decreases as the cells when enter in the S phase of the cell cycle. The highest amount of cyclin E regulates the proper division and maintenance of G1 phase of the cell.

Thus, the correct answer is option (c).