Plants manufacture food through photosynthesis. The rate of photosynthesis is affected by factors like light intensity, carbon dioxide levels, and temperature. Materials and energy flow through an ecosystem as plants use light energy to produce food and oxygen through photosynthesis, and animals consume the plants or other animals to obtain energy and nutrients while returning waste.

1. Lesson 4.
ECOSYSTEM: LIGHT ENERGY
Internal Structure of the Leaf of a
Typical Dicotyledonous Plant

3. 1. How do plants manufacture food?
2. What are the factors that affect
the rate of photosynthesis?
3. How do materials and energy
flow in the ecosystem?