Explain how the shape of the small intestine and the many villi on the inner surface of the wall of the small intestine increase the rate of absorption of digested food molecules from the lumen of the small intestine to the blood.

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

Blood stem cells may develop into any kind of human blood cells. what kind of stem cells are blood stem cells? a. multipotent stem cells o b. totipotent stem cells o c. pluripotent stem cells o d. unipotent stem cells

18. how do the cells in meiosis differ from the cells in mitosis?