what often serves as the second messenger when a hydrophilic amino-acid based hormone binds its receptor?

How are the testes and ovaries similar? a. both produce sex cells. b. both connect internal reproductive organs to the exterior. c. both transport sex cells from their site of production. d. both store mature sex cells.

Speed is the ratio of the distance of an object moves to

Which of the following explains why a tree is often used as a model to represent the principle of common descent