How do you know when there are "Competitive interactions" in ecosystems?

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.

Does all the energy stored by the phytoplankton reach the top level of the pyramid

Around 50,000 rainforest species go extinct every year. select the best answer from the choices provided t f