Topic: Energy Flow
Lesson 1: The Sun as the Principal Energy Source
| Section | Details |
|---|---|
| Objective | – Understand the Sun as the main source of energy for biological systems. |
| Activities | Starter (5 mins): Ask students to list ways the Sun supports life on Earth (e.g., photosynthesis). Main (25 mins): 1. Explain how the Sun provides light energy used by plants to synthesize carbohydrates through photosynthesis. 2. Discuss how energy flows from plants to herbivores and then to carnivores in a food chain. Plenary (10 mins): Students summarize why life on Earth depends on the Sun. |
| Resources | Diagrams of food chains and food webs, whiteboard for explanations. |
| Time | 40 minutes |
| Homework | Draw a food chain with the Sun as the starting point and label the energy flow at each step. |
| Assessment | Class participation in explaining the Sun’s role in energy flow. |
| Past Paper Practice | IGCSE Biology 0610/12/O/N/18 Q2(a). |
Lesson 2: Flow of Energy Through Living Organisms
| Section | Details |
|---|---|
| Objective | – Describe the energy flow through living organisms and its transfer to the environment. |
| Activities | Starter (5 mins): Show a video or diagram of a simple food chain (e.g., grass → cow → human). Main (25 mins): 1. Discuss the transfer of energy as light energy is converted into chemical energy during photosynthesis. 2. Explain energy transfer through feeding (trophic levels), and the eventual loss of energy as heat to the environment. Plenary (10 mins): Students discuss why energy transfer is inefficient between trophic levels. |
| Resources | Food web diagrams, a video clip of energy flow in ecosystems. |
| Time | 40 minutes |
| Homework | Write a paragraph on why energy transfer between trophic levels is inefficient. |
| Assessment | Students’ ability to explain energy transfer at different trophic levels. |
| Past Paper Practice | IGCSE Biology 0610/22/M/J/19 Q4(b). |
Key Notes for Teachers:
- Highlight the Sun’s role in photosynthesis and energy input into ecosystems.
- Explain the concept of energy loss at each trophic level due to heat and respiration.
Key Notes for Students:
- The Sun is the starting point of energy for most ecosystems.
- Energy flows through food chains as organisms consume one another.
- A significant portion of energy is lost as heat during respiration and other processes.
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