Sirius b was an important star in ancient egypt and was used to warn for floods on the nile river. is sirius b brighter or dimmer than the sun? * a) brighter* b) dimmer

Match the types of competition to their descriptions.

19. scientists use meteorites that hit earth to provide evidence of the composition of earth's interior because they hypothesize that

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.