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Discover how energy moves in a straight line from one organism to another.
Did you know that the sandwich you ate for lunch is actually 'recycled' sunlight? Every bite of food you take contains energy that originally came from a star 93 million miles away!
Every food chain begins with the sun. However, animals can't eat sunlight! That's where producers come in. Producers, like green plants, algae, and some bacteria, use a process called photosynthesis to turn sunlight into food energy. Because they 'produce' their own energy, they are always the first link in the chain. Without producers, no other life could exist because there would be no way to capture the sun's power.
Quick Check
Why must a food chain always start with a producer?
Answer
Because producers are the only organisms that can capture energy from the sun to create food.
When a rabbit eats a carrot, the energy from the carrot moves into the rabbit. In science, we show this using an arrow. A common mistake is thinking the arrow points to what is being eaten. Actually, the arrow points in the direction of the energy flow. Think of the arrow as a sign saying 'The energy goes here!' or 'Into the mouth of...' If we have a chain where , it means organism is getting energy from organism .
Let's look at a basic three-step chain: 1. Grass (Producer): Captures sunlight. 2. **Grass Grasshopper**: The grasshopper eats the grass. Energy moves to the grasshopper. 3. **Grasshopper Frog**: The frog eats the grasshopper. Energy moves to the frog.
Quick Check
In the chain: Flower Butterfly Bird, which organism is the producer?
Answer
The Flower.
Food chains are like delicate machines. If you remove one part, the whole thing can break down. This is called a disruption. If a producer is removed, the animals that eat it will starve. If a middle organism (a consumer) is removed, the animals 'above' it lose their food source, and the organisms 'below' it might overpopulate because nothing is eating them anymore. Everything in nature is connected!
Imagine a pond chain: . 1. If a chemical kills all the Algae, the Small Fish will have nothing to eat and will die. 2. Because the Small Fish die, the Large Bass will also run out of food and disappear. 3. One change at the bottom affected the entire top of the chain.
Consider this forest chain: . If a disease removes all the Hawks, what happens? 1. The Squirrel population will grow very fast because no one is hunting them. 2. Too many squirrels will eat all the Acorns. 3. Eventually, the squirrels will run out of food because they over-consumed their own resource.
Which of these is the correct order for a food chain?
What does the arrow in a food chain represent?
If the primary consumer is removed from a food chain, the producer population will likely increase at first.
Review Tomorrow
Tomorrow morning, look at your breakfast and try to trace it back to a producer and the sun. For example: Milk Cow Grass Sun.
Practice Activity
Draw a food chain for an ocean ecosystem using these three items: Shark, Algae, and Small Fish. Remember to point your arrows correctly!