Water movement in plants What is transpiration? Starter: Look at these wet clothes, how are they going to dry? Even in winter? Resources Celery, daffs, straws, coloured water, balloons(Long), Microscopes with nail varnish of stomata on

Glossary Transpiration – the loss of water vapour from the leaves of plants through the stomata when they are open to allow gas exchange for photosynthesis. Done? Write down the word and symbol equation for photosynthesis. Where does each reactant come from? What happens to each product?

Plant Gas Exchange

Notes Carbon Dioxide enters through the stomata when they are opened. Air diffuses in and fills the spaces in the leaf along a concentration gradient. At the same time oxygen that has been produced diffuses out of the leaf down its concentration gradient. When the stomata are open, water also diffuses out…. Why is this potentially a problem?

Gases move into and out of leaves through stomata – these can open and close depending on the time of day or year.

Lets investigate Celery!

Getting water in and out of a plant.

Lets look at some stomata…. Microscopes and ting Diagram of stomata and guard cells.

Transpiration in plants

A word from everybody's Fantasy Grandad http://www.youtube.com/watch?v=w6f2BiFiXiM

What features do roots have to allow effective uptake of water and minerals?

Lets investigate the rate of transpiration

Or Lets investigate Use a wick to model transpiration Wick , boiling tube, drinking straw, blotting paper and card. This represents the leaf transpiring. TASK: describe the model and relate it to transpiration in a real plant.

Look at these wet clothes, how are they going to dry? Even in winter? How can you increase the rate at which the laundry dries? Resources Celery, daffs, straws, coloured water, balloons(Long), Microscopes with nail varnish of stomata on

Factors that affect transpiration Anything that increases PHS increases the transpiration rate. Hot, dry and windy conditions also do- why?

Notes Transpiration is the loss of water vapour through the stomata in a leaf, causing the water to be pulled up the stem from the roots. Transpiration will increase in the day time as stomata are opened up to let CO2 in and O2 out. On a hot or dry day transpiration will also increase as there is a bigger water concentration gradient built up between the leaf and the atmosphere.

Water Tension Water constantly diffuses out of the plant leaves as there is less water outside the plant. Water moves down a Concentration gradient. Roots bring water into the plant bringing minerals into the plant. Water moves into the xylem vessels and through the plant Check out your celery.

Complete the adaptation sheet Done? Start the past paper questions.

Plenary Why do trees die when you cut through the bark all round the tree?