Welcome to GattPrep!
Welcome, energy tracker! ⚡🌾🦅
Have you ever wondered how energy moves from plants to lions—or from grass to goats? Nature has its own “supply chain” for energy and nutrients. In this final lesson of the module, we’ll explore food chains and food webs, how they work, and why they’re essential for survival in every ecosystem.
A food chain is a simple, one-way path showing how energy passes from one living thing to another in an ecosystem.
It always starts with a producer and moves through different levels of consumers.
Basic Example:
| Trophic Level | Organism Type | Example |
|---|---|---|
| 1st | Producers | Grass, algae, maize |
| 2nd | Primary consumers (herbivores) | Grasshopper, cow |
| 3rd | Secondary consumers (carnivores) | Frog, cat |
| 4th | Tertiary consumers (top predators) | Eagle, lion |
| Any Level | Decomposers | Fungi, bacteria (break down dead matter) |
A food web is a network of connected food chains. It shows that most organisms eat and are eaten by more than one organism.
Food webs are more realistic than food chains because they reflect the complexity of nature.
In both food chains and webs, arrows (→) point from the food to the feeder.
For example:Plant → Rabbit means the rabbit gets energy by eating the plant.
| Role | What They Do | Example |
|---|---|---|
| Producers | Make food using sunlight | Green plants |
| Consumers | Eat other organisms | Cow, bird, snake |
| Decomposers | Break down waste/dead things | Mushroom, earthworm |
Understanding food chains and food webs helps us:
📊 Track energy flow in nature
🧬 Understand who eats whom
🐾 Protect endangered species by knowing their role
🔄 Keep ecosystems balanced
Savanna Food Web
Producers: Grass, shrubs
Herbivores: Antelope, zebra
Carnivores: Lion, cheetah
Omnivores: Baboons
Decomposers: Termites, fungi
If lions disappear, the herbivores may overgraze and destroy vegetation—causing imbalance in the ecosystem.
🧠 Problem:
In a pond, algae are eaten by tadpoles, which are eaten by fish. The fish are eaten by birds. Draw the food chain and identify the trophic levels.
✅ Step-by-Step Solution:
Food chain:Algae → Tadpole → Fish → Bird
Trophic levels:
Algae = Producer
Tadpole = Primary consumer
Fish = Secondary consumer
Bird = Tertiary consumer
✔️ Answer:
The food chain shows energy moving from algae to bird, and each step represents a trophic level.
1. Fill in the blanks
(a) Organisms that make their own food are called ______.
(b) A food web is made up of many ______.
Answers:
(a) producers
(b) food chains
2. Match the Organism to Its Role
| Organism | Role |
|---|---|
| (i) Cow | A. Producer |
| (ii) Fungi | B. Decomposer |
| (iii) Grass | C. Consumer |
Answers:
(i) → C, (ii) → B, (iii) → A
3. Short Answer
Why are decomposers important in a food chain or web?
Sample Answer: Because they break down dead plants and animals, returning nutrients to the soil for producers to use.
A food chain is a simple energy path: producer → consumer → top predator
A food web shows how food chains are connected
Producers make food, consumers eat it, and decomposers clean up and recycle nutrients
All parts are connected—losing one can affect the entire system
Create your own food chain using animals and plants found in your community. Label each level: producer, primary consumer, etc. Then think—what would happen if one link in your chain disappeared?
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