Basic 5 · Science · Earth Science
Benefits of the Sun to the Earth
In this topic you will describe the benefits of the sun to plants, animals and people on the earth.
By the end of these notes you should be able to:
- State the sun as the main source of light and heat
- Describe how the sun helps plants make food
- Explain other uses of the sun in daily life
What you already know
- How day and night are formed
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
- B5.2.1.2.1 – Describe the benefits of the sun to the earth
Introduction
Without the sun, the earth would be dark and frozen, and nothing could live on it. The sun is a star, a huge ball of hot gas, and it is the main source of energy for the earth.
1. Light and Heat
The sun gives the earth light and heat. Light lets us see during the day. Heat keeps the earth warm enough for living things. Farmers, traders and fishermen in Ghana plan their work around sunlight. Without heat from the sun, all the water on earth would freeze.
2. Food for Plants and Animals
Green plants use sunlight to make their own food. This process is called photosynthesis. The plant takes in carbon dioxide from the air and water from the soil, and uses the energy of sunlight, trapped by the green substance chlorophyll, to make sugar. Oxygen is given out. Animals then eat the plants, and other animals eat those animals. So all food chains start with energy from the sun.
3. Drying and Preserving
The heat of the sun is used to dry crops and foods so they last longer. Cocoa beans are dried in the sun before they are sold. Fishermen dry fish on racks. Farmers dry maize, groundnuts and pepper. Women dry cassava to make kokonte. Clothes dry on a line in the sun.
4. Other Benefits
| Benefit | Example |
|---|---|
| light | we can see and work during the day |
| heat | keeps the earth warm; dries clothes |
| food | plants make food by photosynthesis |
| water cycle | evaporates water to form clouds and rain |
| vitamin D | sunlight on our skin helps make vitamin D for strong bones |
| solar energy | solar panels turn sunlight into electricity |
| killing germs | sunlight kills some germs on drying bedding |
Safety: Never look directly at the sun. It can permanently damage your eyes. Drink water and stay in the shade when the sun is very hot.
New words
- sun
- The star at the centre of our solar system.
- photosynthesis
- How green plants make food using sunlight.
- chlorophyll
- The green substance in leaves that traps sunlight.
- solar energy
- Energy from the sun.
- solar panel
- A device that turns sunlight into electricity.
- vitamin D
- A vitamin the body makes in sunlight.
Summary
- The sun gives light and heat to the earth.
- Plants use sunlight to make food; animals depend on plants.
- Sunlight dries crops and fish and drives the water cycle.
- Solar panels turn sunlight into electricity.
Class activity: Sun or Shade
- Place a damp cloth in the sun and another in the shade.
- Check them every 15 minutes.
- Record which dries first and explain why.
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. What is the main source of light and heat for the earth?
- A. The sun
- B. The moon
- C. Fire
- D. Stars
Show answer
Answer: The sunThe sun is a star.2. Green plants use sunlight to…
- A. make food
- B. drink water
- C. sleep
- D. grow roots only
Show answer
Answer: make foodThat is photosynthesis.3. Which crop is dried in the sun before sale in Ghana?
- A. Cocoa beans
- B. Pineapple
- C. Garden eggs
- D. Lettuce
Show answer
Answer: Cocoa beansDrying preserves them.4. Solar panels use sunlight to produce electricity.
- A. True
- B. False
Show answer
Answer: TrueThey convert solar energy.5. It is safe to look straight at the sun at noon.
- A. True
- B. False
Show answer
Answer: FalseIt damages the eyes.6. The green substance in leaves that traps sunlight is ______.
Show answer
Answer: chlorophyllIt makes leaves green.7. State three ways people in Ghana use the sun.
Show answer
Answer: Drying cocoa/fish, drying clothes, solar electricity.Any three.8. Explain why animals depend on the sun even though they do not photosynthesise.
Show answer
Answer: They eat plants (or animals that eat plants), and plants make food using sunlight.All food chains start with the sun.
Homework
- List five things in your home or community that depend on the sun and explain how.