In this lesson, students learn that plants make their own food by converting light energy into sugar (stored energy), which the plants then use to carry out their life processes. Students watch a video and do a Web activity to help them construct an understanding of photosynthesis.
- Describe how plants make their own food from water, carbon dioxide, and energy from sunlight captured by their green leaves
Grade Level: 3-5
- One 45-minute block
- Photosynthesis PDF Document
Before the Lesson
- Make a copy of the Photosynthesis PDF Document handout for each student.
1. Ask students:
- Do plants eat?
- Where do they get the energy they need to stay alive?
2. Tell students they are going to investigate how plants make their own food. Have them watch the Photosynthesis video and explore the "Cycle" and "Puzzler" activities in the Illuminating Photosynthesis Web activity. Distribute copies of the Photosynthesis (PDF) handout to students and have them answer all the questions.
3. Assess student understanding of photosynthesis by discussing the following questions:
- Where do plants get the energy they need to grow?
- What ingredients (raw materials) do green plants need for photosynthesis?
- Where do plants get these ingredients?
- In what part of the plant does photosynthesis take place?
- What do plants use the sun's energy to manufacture?
- What do they use the energy stored in glucose for?
- What gas do animals exhale and plants take in?
- What do plants use this gas for?
- What gas do plants give off and animals inhale?
- What do animals use this gas for?
- Why are plants called producers?
4. Have students write a recipe for making glucose and include a picture of each of the ingredients.
5. Discuss the following question:
- Why are plants critical for the survival of animals? What do they make that animals need?
- Have students record the growth of several plants, each exposed to a different amount (duration and/or intensity) of light.