Page 153 - Knowledge Organiser Yr8 24-25

Knowledge Base: Science 8.12 Plants and Photosynthesis Year 8
5. Leaves
5.1
Label the cross section of a leaf.
5.2
What are stomata?
Small holes on the lower surface of the leaf.
5.3
Why do leaves have a large surface area?
To absorb as much light as possible for photosynthesis.
5.4
Which layer of the plant contains to most chloroplasts and why?
The palisade layer because the upper surface of the leaf receives the most light.
5.5
Photosynthesis uses up carbon dioxide gas and releases oxygen gas. How do these gasses enter and leave the leaf?
Through the stomata.
5.6
Why is the top of the leaf covered in a waxy layer?
To reduce the amount of water evaporating out of the leaf.
7. Gas Exchange in Plants
7.1
What is the function of the stomata?
To allow gases to diffuse in and out of the leaf.
7.2 Which gas diffuses into the leaf?
7.3 Which gas diffuses out of the leaf?
7.5 What is the role of guard cells?
7.6 When are stomata open?
7.7 When are stomata closed?
Carbon dioxide. Oxygen.
To open and close stomata. During the day.
At night.
7.4
Why are there air spaces inside the leaf?
To allow the gases to move easily between the leaf cells.
8. Plants are Essential
8.1
Why are plants called producers?
They make their own food by photosynthesis.
8.2
Plants make glucose during photosynthesis. What useful products is glucose converted into by the plant?
Starch as an energy store. Oils as an energy store.
8.3
How are carbohydrates and oils passed on from plants to animals.
When animals eat the plants.
6. Leaves Under the Microscope
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