NAD is the electron carrier which is used in redox reactions in cellular respiration
The closer the light is to the plant the rate of photosynthesis will be greater compared to when the light is further away from the plant the rate of photosynthesis will be lower.
C. Protective over young cubs
i would say the best answer is d
Smooth muscles depolarize as a result of a transmembrane current of Calcium ions. When an action potential depolarizes the muscle cell membrane, it also travels into the body of the cell via the t-tubules. Unlike skeletal muscle, smooth muscle is dependent in two sources of calcium in order to intiate contraction. These two sources are calcium sequestered in the S.R. of the smooth muscle cell.