1. Plant Organ Systems

2. Agenda Take up homework Mitosis match Check seeds and record observations Lesson 2.2 Plant Organ Systems Vocabulary Workbook page 24, #1-5, page 11, #10,11,15

3. Learning Goals Students will define the terms: system, root system, shoot system Students will understand the function and characteristics of the root and shoot systems Students will differentiate between the function and properties of xylem and phloem tissue Students will review the tissues and processes involved in moving water and nutrients Students will discuss the movement and storage of the products of photosynthesis

4. System – a group of tissues and organs that perform specific functions Shoot System – Organs above the ground supports the plant performs photosynthesis transports sap Root System Organs below the ground takes in water & nutrients from the soil transports them to the shoot system

5. Systems Working Together The root and shoot systems are connected by the flow of water, nutrients and hormones through the vascular bundles. This flow is essential for the plant life. Xylem tissue moves water and minerals from the roots to other plant parts. Phloem tissue moves sugars produced by photosynthesis to other plant parts.

6. Water Too Little Water In the Soil nutrients can not be taken up by the roots. nutrients need to be dissolved in water to move through the plant as sap In the leaf photosynthesis can not take place. Too Much Water In the Soil the spaces between soil molecules will be filled with water instead of oxygen root cells will not get enough oxygen for respiration.

7. Moving Water Through the Systems Root hairs are tiny extensions of the cell membranes of the epidermis. They increase the surface area over which water and nutrients can enter the plant. 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” the xylem.

8. The pull from above” The roots push the water column from below. The leaves pull from above. Some of the water in the leaves is used for photosynthesis but more of the water is lost as water vapour through the process of Transpiration. When the stomata open to take in carbon dioxide and release oxygen, water vapour evaporates. This process makes room for more water from the xylem to move into the leaves, pulling the water column in the xylem up. Water’s unique properties also aid in moving water up the xylem. Cohesion is the ability of water molecules to cling to one another. This property holds the water column in the xylem together. Adhesion is the ability of water to stick to certain surfaces. This allows water molecules to cling to the xylem walls which helps prevent the water from flowing back down into the roots.

10. Moving Nutrients Through the System Photosynthesis produces a sugar, called glucose. Glucose is either used by the plant or combines with other molecules to form sucrose or other carbohydrates. Sucrose is the main molecule distributed through the phloem. When sucrose reaches the roots, it is chemically changed to starch and stored. When the starch is needed by the plant it is converted back to sucrose, which dissolves in water and is transported as sap.

11. The Movement of Maple Sap In the spring, sucrose from the roots flows up the phloem to help produce leaf buds. The sap that flows up in Maple trees contains large amounts of sucrose. In the summer and fall, the leaves produce glucose which combines with other molecules to produce sucrose, that moves down the phloem to be stored in the roots as starch. Glucose Sucrose Starch Glucose

12. Success Criteria I have defined the terms: system, root system, shoot system I understand the function and characteristics of the root and shoot systems I am able to differentiate between the function and properties of xylem and phloem tissue I have reviewed the tissues and processes involved in moving water and nutrients I have discussed the movement and storage of the products of photosynthesis