Complete the Starter Question

Water movement through plants How does water move through a plant? Which part of the plant does water enter? Which part of the plant does water leave? What do you know already? With the person next to you discuss for 1 minute what you already know about the movement of water through plants

Movement of water in plants Monday, December 03, 2018 Movement of water in plants Lesson Objectives: Describe the process by which water moves through a plant [C-B] Explain the loss of water from leaves in terms of diffusion of water particles [B-A] Apply understanding to exam style questions [A*] Starter: Which of these leaves are adapted to hot and dry? Which ones are adapted to damp and dark? How? a b c d

Plant transport systems Once water and minerals have entered the root cells, they need to get all the plants tissues. Plants possess specialised tissue, called xylem, to transport water and dissolved mineral salts. Xylem tissue consists of long cells that die and form hollow tubes. These tubes also give support to the plant. The glucose made in leaves by photosynthesis is converted to sucrose and transported to other parts of the plant by strands of living phloem tissue.

What has happened to this poor plant? Transpiration What has happened to this poor plant? Transpiration is the movement of water molecules through the plant. Up from the roots, through Xylem vessels and evaporating out through the stomata in the leaves.

Transpiration in plants

Evaporation and transpiration Evaporation is the process of a liquid turning to gas. Transpiration is the release of water vapour from a plant through the leaves, causing water to move through the plant.

What happens to the water in a plant?

Task You have been given 2 sources of information, you are required to read the information in 2 sources (apart from the blue group who will also use source 3). Make notes from each source, considering some of the key areas e.g. Osmosis and transpiration At the bottom of your sheet you need to synthesis this information into a summary of water transport in plants. This needs to include a description of osmosis, active transport and transpiration.

Moving water against gravity Water that evaporate from the surface of cells inside a leaf by diffusion when the stomata are open. This maintains a concentration gradient, so more water evaporates and diffuses out of the leaf. The loss of water from the leaf pulls water and dissolved mineral salts up through the xylem from the roots. This process is called transpiration. Factors that increase evaporation will also increase transpiration.

What is transpiration and what factors affect it? Temperature. Light levels. Air movements. Carbon dioxide levels. AQA Science © Nelson Thornes Ltd 2006  12

Affecting the rate of transpiration You can measure the rate of transpiration using a potometer

Affecting the rate of transpiration Light intensity Temperature increases Air movement Humidity falls CAN YOU WORK OUT WHY THESE THINGS INCREASE THE RATE OF TRANSPIRATION

The size of the stomata is controlled by guard cells. If a plant loses water faster than it is replaced by the roots, the stomata close to prevent wilting.

Plenary Explain how transpiration causes water to move through a plant from soil to air. (4 marks) Water lost through the leaf to the air by transpiration through stomata. This pulls water up ylem through the plant. This pulls water from roots. Causes water to move into root from soil to water.