Explain why the hormones attach to the target cell and not to other cells

Me with these questions image attached

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.

Energy stored in the bonds that hold together the atoms and molecules of all substances is called a. kinetic energy. b. electrical energy. c. mechanical energy. d. chemical energy.