1. Plants are used for many reasons. List the different ways in which plants can be used. Try and think of the names of three plants for each use.

2. In summer the weed in the school pond is covered in bubbles.
What gas do you think is in the bubbles and how would you test your prediction?

3. Amina put a candle under a large jar. It went out after 15 seconds. She repeated her experiment using a jar with a plant in it. The plant had been kept in the jar on a sunny windowsill. The candle went out after 20 seconds.
Can you explain Amina’s results?
How would you make her experiment more reliable?

4. The atmosphere has changed over many millions of years. Before living things appeared there was no oxygen in the atmosphere.
How do we know that green plants must have appeared on Earth before animals?

5. My grandad has an old paraffin heater in his greenhouse. He always swears that it makes the plants grow faster than an electric heater would.
Do you think he is right?

6. Kuram puts some iodine solution on a piece of potato. It turns dark blue.
What does this mean?
Why does a potato give such a good result for this test?

7. Plants need carbon dioxide and water to grow. They also need minerals from the soil.
What are the three most important minerals and what are they used for?

8. Ben and Joseph were arguing about where wood comes from. Ben said it was made from the soil. Joe disagreed, saying that water was important for making wood. Amy butted in claiming that wood was mostly made from gases in the air.
Can you settle the argument?

9. You put a leaf in some boiling water and bubbles come out of the lower surface.
How do the bubbles get out?
Why do they only come from the lower surface?

10. Leaves are darker green on their upper surfaces.
Can you explain why?