12. In many scientific studies, several variables can affect the results. You want to investigate two related areas: 1 Male rats eat more than female rats do. 2 Large rats, regardless of their sex, eat more than smaller rats do. Design an experiment to test ONE of these two ideas.

Which sentence best expresses the differing opinions of these two book reviews?

Why does the skin of your finger shrink when you wash clothes for a long time?

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.