Water flows into the source end of a sieve tube because ________.

Question

Quizplus · Accepted Answer

Sucrose is actively transported into the sieve tube elements from the photosynthesizing cells, which increases the osmotic pressure inside the sieve tube, making it hypertonic relative to the surrounding cells. This osmotic gradient causes water to flow into the sieve tube from adjacent cells and xylem, facilitating the movement of the sucrose solution through the phloem to various parts of the plant.

Water Flows into the Source End of a Sieve Tube