What does epithelial tissue do?
write this the asnwer in a simple way

Which of the following is true of metabolism in its entirety in all organisms? a) metabolism depends on a constant supply of energy from food. b) metabolism uses all of an organism's resources. c) metabolism consists of all the energy transformation reactions in an organism. d) metabolism manages the increase of entropy in an organism.

How do all types of diffusion/passive transport actually ‘work’ without using even the smallest amount of cellular energy?

Which of the following best describes the purpose of the parathyroid hormone? a. it decreases the blood calcium level and decreases blood phosphorus level. b. it decreases the blood calcium level and increases the blood phosphorus level. c. it increases the blood calcium level and increases blood phosphorus level. d. it increases the blood calcium level and decreases blood phosphorus level.