What is the function of the pectoral fin on the manta ray?

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

If a robot fixed another robot is it a engineer or doctor?

What is the role of the phospholipid belayer in cellular transport in living cells