Question

Sucrose moves into sieve tube elements by?

• A. Diffusion
• B. Endosmosis
• C. Active transport
• D. Exosmosis

Answer 1

The correct option is C Active transport

The mechanism used for the translocation of sugars from source to sink is called the pressure flow hypothesis. As glucose is prepared at the source, it is converted to sucrose. This is moved into the companion cells and then into the living phloem sieve tube cells by active transport. Again active transport is necessary to move the sucrose out of the phloem sap and into the cells which will use the sugar converting it into energy.

Hence, the correct answer is option C.