Many cacti, such as saguaros and barrel cacti, have large stems and no leaves. what function of leaves is taken on by the stems of such cacti?

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 material did the moon come from?

Hey everybody i need with a biology question. all the gametes of isogamous organisms are genetically identical. true false