How Plants Make Food

Define and explain How Plants Make Food in your own words
Use key terms such as photosynthesis accurately
Apply what you have learned to new examples and questions
Avoid the common mistakes learners make with this topic

This lesson focuses on How Plants Make Food: meet photosynthesis in simple words: leaves use sunlight, water and air to make food.

Definition: How Plants Make Food

Meet photosynthesis in simple words: leaves use sunlight, water and air to make food.

Key ideas

The jobs of plant parts

Roots anchor the plant and take in water and minerals. The stem holds the plant upright and carries water up to the leaves. Leaves are the food factories where photosynthesis happens. Flowers make seeds so new plants can grow. Each part has a job, and the plant suffers if any part is damaged.

Green leaves trap energy from sunlight using a green pigment called chlorophyll. The plant uses this energy to turn carbon dioxide from the air and water from the soil into glucose, a sugary food. Oxygen is released as a useful by-product. Because plants make their own food, they are the producers that start every food chain.

Key term — photosynthesis: The process by which green plants use light energy to make food (glucose) from carbon dioxide and water.

Worked example: How Plants Make Food

Why are green plants called producers?

Because they produce their own food by photosynthesis, so they are the starting point of food chains.

Answer: Because they produce their own food by photosynthesis, so they are the starting point of food chains.

Common mistakes

Saying plants eat soil Plants absorb water and minerals from soil, but they make their own food in their leaves using sunlight. Soil is not their food.
Forgetting that roots grow first During germination the root appears before the shoot, so the young plant can absorb water straight away.

Practice

In the fair test example, why must both plants get the same amount of water?

What would happen if only one got water?

So that water cannot explain any difference in growth. If only one plant were watered, you would not know whether light or water caused the result.

Name the four main parts of a flowering plant.

One is underground, one holds the plant up.

Roots, stem, leaves and flower.

What is the job of the roots?

Think about water and holding on.

Roots anchor the plant in the soil and absorb water and minerals.

List three things a plant needs to grow healthily.

Light is one of them.

Any three of: light, water, warmth, air (carbon dioxide).

Quick check

How Plants Make Food — quick check

Which of these best defines "photosynthesis"?

The process by which green plants use light energy to make food (glucose) from carbon dioxide and water.

What happens during germination?

The seed starts to grow: the root emerges first to absorb water, then the shoot grows upwards towards the light.

Key takeaways

How Plants Make Food: meet photosynthesis in simple words: leaves use sunlight, water and air to make food.
The jobs of plant parts: Roots anchor the plant and take in water and minerals.
roots: The part of the plant that grows underground, anchoring the plant and absorbing water and minerals from the soil.
Watch out for: saying plants eat soil

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