Which statement is true about nitrogen and oxygen?

a. they make up about 99.9% of the human body.

b. they are both made of protons, neutrons, and electrons.

c. they are both used to make water molecules.

d. neither contains subatomic particles.

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.

Individuals do not compete directly for resources, but are prey for the same predator

What is the similarities and differences between bacteria and eukaryote?