Beginning in the mouth all the way the toilet- describe the path of food in the digestive system.

Why do carbohydrate molecules function so well as fuel for the body?

What organs comprise the respiratory system of a bird

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.