1. Gas Exchange in the Leaf of a Plant

2. Stomata Closed Open

3. Stomata can control the rate of gas exchange by opening and closing. Stomata have guard cells which can close the stomata pore, to help prevent water loss from the plant

4. Stomata Lower epidermis cell nucleus thick inner wall of guard cell guard cell thick inner wall of guard cell Lower epidermis cell nucleus chloroplast Stomata pore chloroplast

5. The Structure of a Leaf The Structure of a Leaf Stomata Stomata pore Guard cell Air spaces

6. What features of the leaf provide a large surface area and a short diffusion distance Leaves have a very thin flat shape (only 5 cells thin) = large surface area to volume ratio. There are MANY interconnecting air spaces throughout the spongy mesophyll. There are MANY stomata pores that allow gas exchange to take place These features create a very short diffusion pathway

8. Plants- stomata Stomata have guard cells which can close the stomata pore, to help prevent water loss from the plant Stomata also control the rate of gaseous exchange by opening and closing.

9. The Structure of a Leaf The Structure of a Leaf Stomata pore

10. What is the main difference between the gas exchange processes of plants and animals? Plants produce ‘waste’ O 2 during photosynthesis – this can then be used for respiration. ‘Waste’ CO 2 produced by respiration can then be used for photosynthesis.