Nonspecific immunity depends on a newly infected animal's previous exposure to the same pathogen.

utilizes highly specific antigen receptors on B cells.

is based on recognition of antigens that are specific to different pathogens.

is activated immediately upon infection.

Which of the following human activities resulted in the growth of the north american deer population?

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.

Which factor affects the force of gravity between objects? check all that apply. direction distance mass shape time