Which of the following exhibits the highest rate of respiration?

Options

A. Growing shoot apex
B. Germinating seed
C. Root tip
D. Leaf bud

Answer

B

Explanation

Different tissues and organs respire at different rates. A useful rule of thumb is that the greater the overall metabolic activity of a given tissue, the higher its respiration rate. Germinating seeds exhibit the highest rate of respiration. Developing buds usually show very high rates of respiration and respiration rates of vegetative tissue usually decrease from the point of growth to more differentiated regaions. When a plant tissue has reached maturity, its respiration rate will either remain roughly constant or decrease slowly as the tissue ages and ultimately senesces.