Question

what time point represents g₂? chart showing mpf activity (brown) and cyclin (red) concentration over time, with time points 1, 2, 3, 4 marked. y-axis: concentration (high to low).

Explanation:

Step1: Recall G2 phase role

G2 phase precedes mitosis, where cyclin accumulates to activate MPF.

Step2: Analyze graph trends

Cyclin concentration rises (pre-MPF activation) during G2. Time point 3 shows cyclin increasing before MPF peaks (mitosis).

Answer:

3