Plants can generate the pressures needed to transport sugars produced by photosynthesis great distances by

Question

Quizplus · Accepted Answer

Plants use active transport to move sugars from source cells (where they are produced by photosynthesis) to sink cells (where they are used or stored). This requires energy expenditure by the plant to move the sugars against a concentration gradient. The movement of sugars through the phloem is also aided by companion cells, which actively transport ions and other molecules in and out of the phloem to maintain a concentration gradient that favors sugar movement. Amino acids may also play a role in phloem transport, but manipulating their concentration alone would not generate the pressure gradients necessary for long-distance transport. Active transport of water is also important for plant function, but it is not directly involved in sugar transport through the phloem. High water pressures in root hairs are important for water uptake, but not for sugar transport through the phloem.

Plants Can Generate the Pressures Needed to Transport Sugars Produced