Answer:
(a) Since skin cells undergo the process of mitosis, the product of one cell cycle is 2 identical daughter cells.
(b) The levels of p53 protein in the cell will rise in response to DNA damage. This will stop the cycle at one point to give time to the repair machinery to regain stability. As can be seen in the figure, CDK inhibitors have been produced which are responsible for halting the cell cycle.
(c) The S phase (synthesis phase) is when replication of damaged DNA would occur.
(d) p53 responds in one of 3 ways to an event of DNA damage: arresting the cell-cycle, apoptosis (programmed cell death), or repairing the DNA. If there has been a mutation in p53, neither of the three way would take place to prevent more copies of damaged DNA being made. A mutated p53 protein would no longer be able to suppress tumors.
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