Question

9 multiple choice 10 points which protein is a negative regulator of the cell cycle that can initiate apoptosis? cyclin cdk kinase p53 10 multiple choice 10 points which type of cells may enter the g0 phase and not divide? hair follicle cells muscle cells skin cells neurons

Explanation:

• For question 9: Cyclin and Cdk are positive regulators of the cell - cycle. Kinase is a general term for enzymes that phosphorylate other molecules. P53 is a tumor - suppressor protein that can act as a negative regulator of the cell cycle and initiate apoptosis when DNA damage is detected.
• For question 10: Hair follicle cells and skin cells are highly proliferative. Muscle cells can divide under certain circumstances. Neurons are post - mitotic cells that typically enter the G0 phase and do not divide.

Answer:

1. D. p53
2. D. Neurons