Explain one mechanism of translocation of sugars .

Explanation

(I ) The mechanism of translocation of sugars from source to sink is through pressure flow hypothesis .
(ii ) Glucose prepared at source ( by photosynthesis ) is converted to sucrose .
(iii ) Sucrose moves into the companion cells , then into the living phloem sieve tube cells by active transport . this process produces a hypertonic condition in the phloem .
(iv ) Water in the adjacent xylem moves into the phloem by osmosis .As osmotic pressure builds up , the phloem sap moves to areas of lower pressure .
(v ) By active transport sucrose moves into the cells where it is utilised or stored .
(vi ) As sugars are removed , the osmotic pressure decreases and water moves out of the phloem .