1. 2.2 Plant Organ Systems
Learning Objective: Learn to describe how plant organs work together to meet the needs of a plant. Keywords: System Root System Shoot System

2. Moving Water Through the Systems
(Pages 72-74)
“The push from below” – Water enters the root by osmosis and moves toward the centre of the root into the xylem vessels. The pericycle prevents the water from moving backward. Root pressure builds up in the xylem and pushes water “up”.
Tiny root hairs increase the surface area of the root.
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3. Moving Water Through the Systems
(Pages 72-74)
“The pull from above” – While the roots push the water column from below, the leaves pull from above. Transpiration aids in this process.
Unique Properties of Water:
1) Cohesion – the ability of water molecules to cling to each other
2) Adhesion – ability of water to stick to other surfaces (e.g. wall of xylem vessel)
Copyright © 2010 McGraw-Hill Ryerson Ltd.

4. Moving Water Through the Systems
(Pages 72-74)
Copyright © 2010 McGraw-Hill Ryerson Ltd.

5. The Movement of Maple Sap
(Page 75)
In the spring, sucrose from the roots flows “upward” to help produce leaf buds. In the summer and fall, the leaves produce glucose that moves “downward” to be stored in the roots.
Glucose
Glucose
Sucrose
Sucrose
Starch
Starch
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6. Transport of Sucrose (sugar) Through a Plant
Copyright © 2010 McGraw-Hill Ryerson Ltd.