Plz help its overdue I will give 25 points and brainiest

What does polymerase chain reaction (pcr) do? o a. separates dna fragments by size o b. cuts a dna sample into fragments o c. provides an overall picture of a person's chromosomes o d. makes more copies of a sample of dna

If a checkpoint detects damaged dna, the checkpoint may

This is a biological reaction due to a stimulus. i need this quickly !