Section 2 2 Plant Organ Systems Plant Organ

Section 2. 2 Plant Organ Systems

Plant Organ Systems System – a group of tissues and organs that perform specific functions Shoot System – supports the plant, performs photosynthesis, and transports sap Root System – takes in water & nutrients from the soil and transports them to the shoot system Diagram 2. 2 -1

Importance of Water • plants cannot survive without water WHY? 1. nutrients need to be dissolved in water in order to be absorbed 2. photosynthesis cannot take place without water • too much water is also bad WHY? • if spaces between soil molecules are filled with water, there will not be enough room for oxygen

Moving Water Through the Systems “The push from below” • How does water move upward in a plant (against gravity)? • 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 Diagram 2. 2 -2

Moving Water Through the Systems “The pull from above” • while the roots push the water column from below, the leaves pull from above. Transpiration aids in this process. Diagram 2. 2 -4

The Movement of Maple Sap • 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 Sucrose Starch

Section 2. 2 Review Things you should now know: • the function and characteristics of the root and shoot systems • the function and properties of xylem and phloem tissue • the tissues and processes involved in moving water and nutrients • the movement and storage of the products of photosynthesis

Homework • Read pg. 70 -75 in the student textbook. • Complete questions # 1 -6