In what structure does active transport take place in the nephron

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

Which direction does the energy flow in this energy pyramid ?

Genetic disorders can result when sister chromatids fail to seperate properly. during what phase is this problem most likely to occur?