I’m getting worried why does my dog twitch a bit in her sleep?

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

Parasitism could be considered a form of which of these types of relationships? -mutualism -commensalism -predator-prey -mimicry

Which layer will become saturated first when rain falls?