Ecology & Food Web Lab
Explore food chains, food webs, trophic levels, energy transfer and the effects of changing populations in a simplified ecosystem.
Grass uses light energy to make organic matter through photosynthesis and forms the base of this simplified food web.
Explore organisms, trace food chains or change population levels to investigate this simplified ecosystem.
🎯 Aim
To study feeding relationships, trophic levels, energy flow and the possible effects of population changes within a simplified terrestrial ecosystem.
🧰 Virtual Apparatus
Food-web model, organism cards, population controls, food-chain tracer, disturbance scenarios, energy pyramid and observation table.
📘 Theory
Organisms in ecosystems are connected through feeding relationships. A food chain shows one pathway, while a food web shows several interconnected pathways.
🌿 Trophic Levels
Plants capture light energy and produce organic matter through photosynthesis.
Herbivores obtain energy by feeding on producers.
These consumers feed on organisms at lower trophic levels.
Predators may occupy higher positions in a particular food chain.
🔗 Example Food Chains
🌾 Grass → 🦗 Grasshopper → 🐸 Frog → 🐍 Snake → 🦅 Hawk
🌾 Grass → 🐇 Rabbit → 🦅 Hawk
Because the hawk can receive energy through more than one feeding pathway, these chains can form part of a larger food web.
⚡ Energy Transfer
Energy available to organisms generally decreases as energy moves through successive trophic levels because organisms use energy for metabolism, movement, maintenance and other life processes, and some energy is dissipated as heat.
🍄 Role of Decomposers
Decomposers such as fungi and many microorganisms break down dead organic matter. This process helps return nutrients to the environment where they can become available to producers again.
📋 Observation Table
| Trial | Grass | Insects | Rabbits | Frogs | Snakes | Hawks | Condition |
|---|---|---|---|---|---|---|---|
| Change the ecosystem and press Record. | |||||||
📝 Procedure
- Identify the producer in the ecosystem.
- Identify the primary consumers.
- Identify the higher-level consumers and decomposer.
- Click organisms to read their ecological roles.
- Select Food Chain and trace a feeding pathway.
- Select Food Web to observe interconnected pathways.
- Increase or decrease one population.
- Press Run to evaluate the simplified model.
- Apply a drought or predator-loss scenario.
- Compare the resulting population balance.
- Press Record to add an observation.
- Reset the ecosystem and test another scenario.
🧠 Ecology Challenge
🎓 Quick Viva
1. What is a producer?
An autotrophic organism that produces organic matter using an energy source; green plants commonly do this through photosynthesis.
2. What is a primary consumer?
A consumer that feeds directly on producers in a particular food chain.
3. What is the difference between a food chain and food web?
A food chain represents one feeding pathway, while a food web represents multiple interconnected feeding pathways.
4. What do arrows represent in this food web?
They show the direction of energy transfer from food or prey toward the consumer.
5. Why is less energy generally available at higher trophic levels?
Organisms use much of the energy they obtain for metabolism and other life processes, and energy is dissipated as heat.
6. What is the role of decomposers?
They break down dead organic matter and contribute to nutrient cycling.
7. Is the 10% energy-transfer rule exact?
No. It is a simplified educational approximation. Actual transfer efficiency varies.
✅ Result
The virtual experiment demonstrates that organisms are linked through feeding relationships and that multiple food chains can form a food web. Changes to one population can potentially influence other parts of the ecosystem.