The Power of Light
Ages 4 to 5 (one 25 minute session)
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Objectives:
- To help children understand what the sun does for a plant
- To show that sunlight physically affects plants
Materials:
- 4 week old transplants
- Potting soil
- Liquid fertilizer
- 4 inch pots
- Labels and a lead pencil
- Black construction paper
- Staples and scotch tape
Set up:
Plant some wheat or oat seeds 4 weeks before the experiment is to take place.
Part One:
Talk about what plants need to grow (nutrients and sunlight). Introduce the term photosynthesis and what it means. Talk about what might happen to plants if no sun were available for them to use. Have them speculate and write those ideas down in their experiment journal. Have them fill the four inch pots. Have them transplant a single plant into each pot. Mix the fertilizer according to the directions on the box of Miracle Grow, in a glass jug, so the children can see the color change. Talk about what fertilizer is. Water each plant with the fertilizer water.
Part Two:
Using the black construction paper, help the children construct a tube that can be placed over one of the plants to exclude sunlight. Be sure the tube has one end covered and that absolutely NO light can get in. Wait one week and observe the results. The plant should be considerably lighter green than usual. This plant reaction is called etiolation.
Questions to ask:
- What does the sun do for the plant?
- When do plants “grow”, at night or in the daytime?
- What do you think photosynthesis means?
- Why are plants green?
- What is a chloroplast?
- What would happen if a plant didn’t get any light?
