Is a tundra cold or hot are there a lot of animals there yes or no what kind of animals are there

Epinephrine is a hormone released from the adrenal gland of the body, most often in a stressful situation. it is known as the "fight-or-flight" hormone. one way that it causes a response in the body is to activate receptors on muscle cells. where are these cellular receptors located? a. on the cell membrane b. in the nucleus c. on the cell wall d. around the mitochondria

In what for do plants utilize nitrogen? why do they need nitrogen?

Which zone within the open-ocean zone is home to the most organisms? deep zone surface zone intertidal zone transition zone