How are mature and newborn skull different regard to composition

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

An organism has the following traits multicellular cant photosynthesize has a skull. wht kingdom does this organism most likely belong too?

Describe characteristics of a good respitory surface