Basic 3 · Science · Earth Science
Why the Sun is Important
In this topic you will learn why the sun is important to life on Earth.
By the end of these notes you should be able to:
- State the importance of the sun
- Explain how plants use the sun
- Describe how people use the sun's heat
What you already know
- Sources of light (Basic 2)
Copy everything that has a blue line on its left into your notebook. The other parts are for reading.
- Strand
- Cycles
- Sub-strand
- Earth Science
- Indicator
- B3.2.1.2.1 – Know the importance of the sun to the earth
Introduction
Without the sun, the Earth would be dark and frozen. Plants could not grow and we would have no food.
1. Importance of the Sun
| Gift | Example |
|---|---|
| light | we see during the day |
| heat | keeps the Earth warm |
| food for plants | plants make food using sunlight |
| drying | cocoa beans, fish, clothes |
| solar energy | solar panels make electricity |
| vitamin D | sunshine helps our bones |
2. A Simple Test
- Put one potted seedling in the sun and one in a dark cupboard.
- Water both the same.
- After a week, compare them.
The seedling in the dark becomes pale and weak.
Safety: Never look directly at the sun.
New words
- solar
- From the sun.
- solar panel
- A board that turns sunlight into electricity.
- vitamin D
- Something our body makes in sunshine for strong bones.
- energy
- The power to do work.
Summary
- The sun gives light and heat.
- Plants need sunlight to make food.
- People use the sun to dry crops and make electricity.
Class activity: Sun and Shade Seedlings
- Put a damp cloth on one seedling's pot and keep both watered.
- Place one in the sun and one in the dark.
- Record what happens after a week.
You need: Potted maize seedling, Damp cloth, Printed photographs of sun-dried fish, Cocoa
Exercises
Answer in your exercise book first, then check your answers.
1. Which do plants need sunlight for?
- A. Making food
- B. Sleeping
- C. Walking
- D. Swimming
Show answer
Answer: Making foodPlants use sunlight to make food.2. What turns sunlight into electricity?
- A. Solar panel
- B. Fan
- C. Bucket
- D. Radio
Show answer
Answer: Solar panelSolar panels use sunlight.3. The sun dries cocoa beans.
- A. True
- B. False
Show answer
Answer: TrueFarmers dry beans in the sun.4. A seedling grows best in a dark cupboard.
- A. True
- B. False
Show answer
Answer: FalseIt needs sunlight.5. Power from the sun is called ______ energy.
Show answer
Answer: solarSolar means from the sun.6. Give three ways the sun is important.
Show answer
Answer: Any three: light, heat, plant food, drying, solar energy, vitamin D.The sun supports life.
Homework
- Dry a wet cloth in the sun and one in the shade. Which dries faster?