Back to: ZOOLOGY 100 Level
It’s always a joy to see you here, ready to learn and grow. You are truly doing something special for yourself! Today, we will talk about trophic levels and energy flow. Don’t worry — it’s easier than it sounds. Think of it like how food passes from one person to another at a party — but in nature! Let’s go!
Trophic levels and energy flow
What are Trophic Levels?
Trophic levels are the different stages in a food chain where energy is transferred from one group of living things to another.
Each level shows who eats who and who gets energy from where.
Here are the main trophic levels:
- Producers (First Trophic Level):
These are plants. They make their own food using sunlight through a process called photosynthesis. - Primary Consumers (Second Trophic Level):
These are herbivores — animals that eat plants (e.g., cows, goats, rabbits). - Secondary Consumers (Third Trophic Level):
These are carnivores that eat primary consumers (e.g., snakes that eat rats). - Tertiary Consumers (Fourth Trophic Level):
These are bigger carnivores that eat other carnivores (e.g., lions, hawks). - Decomposers:
These are organisms like fungi and bacteria that break down dead plants and animals, returning nutrients to the soil.
What is Energy Flow?
Energy flow is the movement of energy through the trophic levels of a food chain or food web.
- Energy starts from the sun.
- Plants capture the sun’s energy.
- Animals eat the plants and get the energy.
- Other animals eat those animals and get part of the energy.
But something important happens — energy is lost at every level!
Most of the energy is used for activities like running, breathing, and even producing heat. Only a small part (about 10%) is passed on to the next level.
Simple Example:
If a plant gets 100 units of energy from the sun, only about 10 units go to the goat that eats it. Then only about 1 unit reaches the lion that eats the goat.
This is called the 10% rule!
Energy Pyramid
If we draw the flow of energy in a picture, it looks like a pyramid:
- Big energy at the bottom (plants).
- Smaller and smaller as you go up (animals).
- Top predators have the least energy.
Summary
- Trophic levels show the different feeding stages in a food chain.
- Energy flows from the sun → plants → herbivores → carnivores.
- At every step, most of the energy is lost, and only a small amount moves up.
- The energy pyramid shows that there’s less energy at higher trophic levels.
Evaluation
- What is a trophic level?
- Name the first trophic level in a food chain.
- Explain the 10% rule in energy flow.
- Why is less energy available at higher trophic levels?
- What role do decomposers play in the energy flow?
Never forget how brilliant you are! Every lesson you complete adds another golden brick to the strong future you are building. Afrilearn is super proud of you, and we can’t wait to see you shine even brighter. Keep moving forward, champion!