Can you explain the process of PCR (including the source of polymerase)

a lot of people sadly don't know the best way to learn is cheating off of your friends or this amazing thing called google

i wish i could with all of them i can barley see the first one so here's the answer to the first one b

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.