I the otter , sea urchin , kelp community , what trophic level is the kelp ? A. Producer
B. Primary consumers
C. Secondary consumers
D. Tertiary consumers

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.

(99 points) be serious! how do farts work? how do you fart without it stinking? serious answers only

Which line in the graph above best illustrates an effect of the carbon dioxide level in the blood on breathing rate before, during and after a period of exercise? 1.b,2.c,3.a,4.d