1. Lesson 2: Photosynthesis 1. The organs, tissues and specialised cells in plants support photosynthesis in a healthy organism

2. time amount of carbon dioxide in the room What’s happening in here? Why is the graph less steep now? 3.3b Change

3. Sink or float? 1. Place a leaf in a 250ml beaker filled with water. 2. Does the leaf float? Why? Why not?

4. Why leaves float Leaves float because they are full of air. 3.3b Leaves

5. Photosynthesis carbon dioxide + water  glucose + oxygen The air spaces in a leaf are like the ones in our lungs – they provide a large surface area for gas exchange. IN OUT 3.3b Leaves Carbon dioxide Oxygen

6. Leaves float because they are full of air. Oxygen production

7. If the air is replaced by water they sink.

8. Oxygen bubbles gather in the leaf and make it rise.The faster the oxygen is produced, the sooner the leaf discs rise.

9. Practical!  We will see how light intensity affects the photosynthesis

10. 1. Write a hypothesis: If…..then….because 2. What are the variables? 3. Record your results in a data table. 4. Graph your results. Remember: use pencil and ruler. use the whole page. axis must be linear label axis with units write a title plot the data correctly draw a curved line of best fit 5. Reflect on your results, are they accurate? What could have affected their accuracy?

11. 1. Sink your leaves 2. Remove air from syringe 3. Place 5cm, 10cm and 15cm from the light. 4. Record time it takes for leaves to float.