Arrange the following five events in an order that explains the mass flow of materials in the phloem.A. Water diffuses into the sieve tubes.B. Leaf cells produce sugar by photosynthesis.C. Solutes are actively transported into sieve tubes.D. Sugar is transported from cell to cell in the leaf.E. Sugar moves down the stem.

Movement which is present on phloem occurs by mass flow from sources of sugar to sugar sinks. The movement which is present in phloem is bidirectional. In this flow the glucose which is synthesized in the leaves is converted into sugar. Sugar in the form of sucrose is going into the companion cells and later into the phloem sieve tube cells with the help of active transport.

These are the following five events in an order which explains the mass flow of materials in the phloem.

1) Leaf cells produce sugar by photosynthesis.

2) Sugar is transported from cell to cell in the leaf.

3) Solutes are actively transported into sieve tubes.

4) Water diffuses into the sieve tubes.

5) Sugar moves down the stem.