The polymerase chain reaction can only be used to amplify genes that have already been cloned and sequenced. Why is this true?

Which of the following represents a negatively charged ion? of t 7

What sentence best supports the statement that hormones are involved in the regulation of homeostasis? a. the hormone erythropoeitin increases the production of red blood cells when oxygen levels are low. b. the hormone oxytocin promotes labor contractions of the uterus during childbirth. c. the hormone melatonin induces sleep and its production is slowed by exposure to light. d. the hormone cortisol suppresses the immune system and is produced when the body is under stress.

What is the period of cell life when it is conducting