Success Homeschool

Year 7 Science · What plants need to grow

Name: ______________________

Date: ____________

1. In a test of how water affects growth, what is the independent variable?
- ☐ (a) The height of the plants
- ☐ (b) The amount of water
- ☐ (c) The type of seed
- ☐ (d) The size of the container
2. What do seedlings grown in the dark usually look like?
- ☐ (a) Short and dark green
- ☐ (b) Exactly like those in light
- ☐ (c) Tall, thin and pale
- ☐ (d) Covered in flowers
3. Which gas do plants take in for photosynthesis?
- ☐ (a) Carbon dioxide
- ☐ (b) Oxygen
- ☐ (c) Helium
- ☐ (d) Nitrogen
4. Why use several seeds in each tub?
- ☐ (a) To make it messy
- ☐ (b) To use up the packet
- ☐ (c) So the seeds grow faster
- ☐ (d) To make results more reliable
5. Which plant is adapted to dry inland Australia?
- ☐ (a) Tree fern
- ☐ (b) Spinifex
- ☐ (c) Water lily
- ☐ (d) Mangrove
6. Seedlings measured 12 mm, 15 mm and 18 mm. What is the average height in mm? (number)
7. Which gas do plants give off during photosynthesis?
8. When a seed starts to sprout, we say it g_________.

Answer sheet

1. The amount of water — The independent variable is the one thing you change: the amount of water.
2. Tall, thin and pale — Without light, seedlings stretch, look thin and lose their green colour.
3. Carbon dioxide — Plants use carbon dioxide, water and light energy to make sugar.
4. To make results more reliable — More seeds and repeats reduce the effect of one unusual seed.
5. Spinifex — Spinifex grasses grow on dry, sandy inland plains.
6. 15 — (12 + 15 + 18) ÷ 3 = 45 ÷ 3 = 15 mm.
7. oxygen — Photosynthesis releases oxygen.
8. germinates — Sprouting is germination.