KS3 · Biology

Plant nutrition: making their own food

A seed lands in the soil, gets watered, and grows into something enormous. So what is it eating? Surprisingly, it takes in no food at all.

Biology · Plant nutrition

Is it food? Run the two-part test

In science, something only counts as food if it gives an organism BOTH energy AND materials for growth and repair. Sort each thing below by what the plant uses it for. Tick every circle that applies, then check. Watch which item ends up in the middle.

  • A A source of energy for the plant
  • B A source of materials for growth and repair
  1. Light
  2. Water
  3. Minerals
  4. Gases from the air
  5. Carbohydrate the plant makes

Biology · The whole plant

What goes in, and where is the food made?
lightgases from the airwater and minerals

View: What goes in. Showing 2 layers: The plant, What goes in

View

Explore

Switch the view, then tap a region to explore it.

Light and gases in through the leaves. Water and minerals in through the roots.

Switch the view, then tap a region to explore it.

Biology · Why minerals matter

?

Reason it through

Minerals are not food, so why does a plant need them?

Link 1 of 4

First link · your turn

A plant's food is carbohydrate. Which elements is carbohydrate made of?

2
Locked — reveal the link above first
3
Locked — reveal the link above first
4
Locked — reveal the link above first

Biology · A food chain, link by link

Step along the chain and ask each time: who made this food?

Biology · Where does a plant get its food?

Which idea is closest to yours?

A plant grows in a pot of soil. It is watered and sits in the light.

Where does this plant get its food from?
How sure are you?

WHAT YOU'VE LEARNED

A quick recap of today's lesson.

Spoiler: it is not what you think.

What you need to know

  • In science, food is a substance an organism uses as a source of both energy and materials for growth and repair.
  • Plants take in light and gases from the air through their leaves, and water and minerals through their roots. None of these is food.
  • Plants make their own food, carbohydrate, in their leaves and other parts above the ground. It is then transported to all parts of the plant.
  • Plants use carbohydrate as a fuel for respiration, which provides energy for their life processes, and as a source of materials for growth and repair.
  • A producer makes its own food. A consumer gets its food by eating other organisms. Every food chain starts with a producer.

The big picture

A plant takes in light, gases, water and minerals, but none of them is food. A plant makes its own food, carbohydrate, in its leaves and other parts above the ground. That makes plants producers, and every food chain on Earth starts with one.

Key points

1Food has to give both energy and materials. Light, water, minerals and gases each give only one of the two.
2Plants take in no food. They make carbohydrate in their leaves and other parts above ground.
3Minerals are not food, but they supply elements such as nitrogen for making proteins and fats.
4Plants are producers, so all the food in every food chain is first made by a plant or another producer.

Worked example

Problem

Lena eats a leaf salad for lunch. Is Lena a producer or a consumer, and where was the food in her salad first made?

⚠ Watch out

Mixing up "needs" with "food". A plant needs water and minerals to stay alive and grow, but that does not make them food. Food has to give energy and materials. Water and minerals give materials only.

🧠

Memory hook

Food has to pass BOTH halves of the test: energy AND materials. Everything a plant takes in scores one out of two. Only the carbohydrate it makes scores two out of two.

✓

Check yourself

A gardener mixes minerals into the soil and says, "That is my plant's food." Explain why minerals are not food, and where the plant's food really comes from.

Flashcards

(13)
In science, what is food?
Any substance an organism uses as a source of both energy and materials for growth and repair.
How does a plant use light?
Only as a source of energy. It gives no materials, so light is not food.
Which things does a plant use as materials only?
Gases, minerals and water. None of them is food.
Where does a plant take in light and gases from the air?
Through its leaves.
Where does a plant take in water and minerals?
Through its roots, from the soil.
What food does a plant make, and where?
Carbohydrate, in its leaves and other parts above the ground.
Once carbohydrate is made, where does it go?
It is transported to all parts of the plant.
What two jobs does carbohydrate do for a plant?
It is a fuel for respiration, which gives energy for the plant's other life processes, and a source of materials for growth and repair.
Which elements make up carbohydrate?
Carbon, hydrogen and oxygen.
How does a plant make proteins and fats?
It combines carbohydrate with other elements, such as nitrogen from minerals.
What is a producer? What is a consumer?
A producer makes its own food. A consumer gets its food by eating other organisms.
What does every food chain start with?
A producer. All the food in every food chain is made by plants and other producers.
Do plants take in food from the soil?
No. A plant takes in no food from its surroundings. It makes its own.

Tap any card to flip it, or use Study as deck to go through them one at a time. In the full lesson these run as a spaced-repetition deck — you rate each card Hard, Good or Easy and the tricky ones keep coming back until they stick.

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How this lesson was checked. This KS3 Biologylesson was published through Lightbulb Learning's human-designed editorial process — the educational standards, accuracy rules and publication checks it must pass were authored and approved by Philip Halpin. It passed subject-specific assessment, automated educational checks and technical publication verification before going live (publication checks completed 2 October 2026). Published pages are monitored, human spot-checking is ongoing across the lesson library, and anything found wrong is corrected or withdrawn. How our lessons are made and checked. Spotted a mistake? Email hello@lightbulblearning.co and we'll review it.