11.1 · How Producers Make Their Own Food

From Ohio 5th Grade Science Power Workbook · Chapter 11 · Lesson 11.1.

Big idea: Producers use the sun's energy to make their own food.

Learning goals: Explain where a producer's energy comes from

Explain why soil and water are not the plant's energy

Name Ohio producers

The sun is the energy

A producer does not eat. It makes its own food.

Sunlight lands on the plant. The plant uses that energy to make food. The food stores the energy until the plant needs it.

This process has a name: photosynthesis. You do not need to know its steps. You do need to know what it does — it turns the sun's energy into food.

Soil and water are not food

Plants do need water. They do need things from the soil.

But those are not where the energy comes from. The energy comes from sunlight. Water, air and a little from the soil are the building materials, not the fuel.

A plant kept in the dark with plenty of water and soil will still run out of energy.

Worked examples

Question: A student puts one plant on a windowsill and one in a dark closet. Both get the same water and the same soil. After two weeks the closet plant is pale and weak. Explain why.

Steps: Check what was the same. Water and soil were the same for both.

Check what was different. Only the light.

A producer needs light to make its food. Without light it cannot make food, however much water it gets.

Answer: The closet plant had no light, so it could not make food. Water and soil are not the plant's energy — sunlight is.

Common mistakes

Plants do not eat soil

Plants grow in soil and need watering, so it feels obvious that soil and water must be their food.

They are not. The sun supplies the energy. Water, air and soil supply materials the plant builds with. A plant in the dark starves no matter how well it is watered.

Check your thinking: Ask where the energy comes from, not what the plant is sitting in.

Not everything gets energy by eating

Animals eat, so it is easy to assume every living thing must.

Producers do not eat at all. They make their own food using the sun's energy. That is exactly what makes them producers.

Check your thinking: Before you answer, ask whether the organism is a producer. If it is, it makes food rather than eating it.

Ohio connection

Why an Ohio corn field looks the way it does

Ohio farmers plant corn in long rows with space between them, not packed tightly together.

Space means sunlight reaches more of each plant. The sunlight is the energy the corn uses to make its food, so more light means more growth.

Think: A weed growing in the shade of a corn plant often stays small. Explain why, using what you know about producers.

Remember

Sun is fuel; water, air and soil supply the materials

A plant needs all of them, for different jobs. The sun gives the energy. Water, air and soil give materials to build with. Only one of them is the fuel.

Practice tip

Remember: Ohio wants the concept, not the chemistry.

Tip: Ohio does not ask for the steps of photosynthesis. You will be asked where a plant's energy comes from. The answer is the sun.

Written practice

A classmate says plants get their energy from the soil. Explain why this is wrong and say where the energy really comes from.

Sample response: Plants get their energy from sunlight, not from soil. Water, air and soil do matter, but they supply materials the plant builds with rather than energy. You can show this by putting a watered plant in the dark. It still has soil and water, but with no light it cannot make food and it weakens.

Scoring guide: 1 point: says the energy comes from sunlight.

1 point: explains that soil and water supply materials the plant needs, but not the energy — or gives the dark-room evidence.

This targets Ohio's listed misconception that plants get their energy from the ground or water. The energy comes from sunlight.