Arrange the following five events in an order that explains the mass flow of materials in the phloem.
1)Water diffuses into the sieve tubes.
2)Leaf cells produce sugar by photosynthesis.
3)Solutes are actively transported into sieve tubes.
4)Sugar is transported from cell to cell in the leaf.
5)Sugar moves down the stem.

Question

Quizplus · Accepted Answer

First, leaf cells produce sugar by photosynthesis (2). Then, the sugar moves from cell to cell in the leaf (4) and gets actively transported into the sieve tubes (3). Next, water diffuses into the sieve tubes (1), creating a pressure gradient that causes the sugar to move down the stem (5). Therefore, the correct order is 2, 4, 3, 1, 5, which is option C.

Arrange the Following Five Events in an Order That Explains