Question

When referring to phloem transport, the "sink" in roots is created by __________.

A. the osmosis of water into xylem cells
B. the active transport of sugars from phloem to cortex cells
C. the absorption of water from the soil through epidermal cells
D. the active transport of mineral ions into xylem cells
E.All of the listed responses are correct.

Answer 1

The "sink" in roots in phloem transport is created by the active transport of sugars from phloem to cortex cells.

Step-by-step explanation:

The "sink" in roots, when referring to phloem transport, is created by the active transport of sugars from phloem to cortex cells.

In the phloem, sucrose concentration in the sink cells is lower than in the phloem STEs because the sink sucrose has been metabolized for growth or converted to starch for storage. Unloading at the sink end of the phloem tube occurs by either diffusion or active transport of sucrose molecules from an area of high concentration to one of low concentration.

The absorption of water from the soil through epidermal cells (option C) and the active transport of mineral ions into xylem cells (option D) are not directly involved in creating the "sink" in roots in phloem transport.