Question

what steps are involved in phloem loading ... AS levels​

Answer 1

Answer:The glucose prepared in the leaves is converted into sugar. The sugar in the form of sucrose is moved into the companion cells and then into the living phloem sieve tube cells by active transport. This creates a hypertonic condition in the phloem. Water in xylem vessels adjacent to phloem moves through endosmosis.

Explanation:

Answer 2

• When  the  phloem  cells,  just  near  the  source, for  example  green  leaves  attain  higher  concentration  of sugars, it is called the process of phloem loading.
• Sucrose is photosynthesised in the chloroplasts of mesophyll cells of leaves.
• Mesophyll cells are connected with each other through plasmodesmata.
• Similarly plasmodesmata are also  present  between  the  mesophyll  cells  and  companion cells and also between mesophyll cells and sieve tubes.
• There plasmodesmata are the “channels” meant for the passage of sucrose.