The pores in the surface of a sponge that pass incoming water to the body are called and the opening by which water passes out of the sponge is called the

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.

What is the difference between topsoil and clay?

Can an organism fill more than one trophic level?