In Early Experiments to Understand the Control of the Cell

Multiple Choice

In early experiments to understand the control of the cell cycle, researchers fused HeLa cells that were at different stages of the cell cycle. What did the results of these experiments suggest? ​

A) The concentrations of cyclin dependent kinases (Cdks) fluctuate throughout the cell cycle.
B) The concentrations of cyclins fluctuate throughout the cell cycle.
C) The cell cycle has three checkpoints through which the cell must pass in order to progress through to mitosis.
D) Microtubules play an essential role in the progression of the cell cycle.
E) Molecules in the cytoplasm control the progression of the cell cycle.