(N/A) To explain transport in plants,we must consider the following questions:
$1$. How does water reach the top of tall trees?
$2$. Why do substances move from one cell to another?
$3$. Do all substances move in a similar way?
$4$. Is metabolic energy required for moving substances?
Plants need to transport molecules over very long distances,often much further than animals. Unlike animals,plants lack a circulatory system,yet water absorbed by the roots must reach all parts of the plant,including the very tips of growing stems. Similarly,food synthesized by leaves through photosynthesis must be transported to all parts of the plant,including root tips embedded deep in the soil. Additionally,movement over short distances—within cells,across membranes,and from cell to cell within tissues—is essential for plant survival.