MAK LABS — Std 5 EVS 1 Chapter 3 The Earth and its Living World

1What’s the solution? Dark patches appear on the skin after exposure to the sun.

When you spend time in the sun, dark patches can appear on your skin. This happens because the skin produces more of the pigment called melanin to protect itself from the sun’s harmful rays. The extra melanin can cause uneven dark spots on the skin. Protecting the skin from excessive sun exposure can help prevent these dark patches.

2Use your brain power!

(a) Why are micro-organisms important?

Microorganisms are important because they help recycle nutrients in nature, make food, support medicines, and clean up pollution. They break down dead plants and animals and release nutrients back into the environment. Some microorganisms are used to make foods such as cheese and yogurt. They are also useful in producing medicines and in cleaning harmful substances from the environment.

(b) Think about all the foodstuffs obtained from the sea. Find more information and write ten lines about them.

1. Fish is a nutritious food obtained from the sea.

2. Shrimp is a tasty seafood that provides useful nutrients.

3. Lobster has edible meat and provides important nutrients.

4. Crab meat contains vitamins and minerals.

5. Oysters are rich in nutrients such as iron and vitamin B12.

6. Mussels are shellfish that provide vitamins and minerals.

7. Seaweed is a nutritious sea plant used in salads and other foods.

8. Calamari, or squid, is a seafood eaten in many parts of the world.

9. Tuna is a popular fish and is a source of useful oils and protein.

10. Scallops are shellfish that provide vitamins and minerals.

These foods from the sea provide a variety of nutrients and are important sources of food for people.

This is a model answer. Write the information in your own words in the notebook.

3Answer the following questions.

(a) What are clouds made of?

Clouds are made up of water vapour.

(b) What is meant by ‘biosphere’?

Living things exist in the lithosphere, hydrosphere and atmosphere. They also interact with these spheres. This living world constitutes the biosphere.

(c) Make a list of the landforms you see in your surroundings and give a description of any two of them.

The exact landforms depend on your surroundings, so the list must be based on what you observe. Worked example: Hill — a raised area of land that is smaller and lower than a mountain. Plain — a broad area of mostly level land.

Write the landforms you actually see around your home or school and describe any two in your own words.

4In the following sentences, underline the words that refer to landforms.

(a) Anil lives at the foot of a hill.

Hill

(b) Ria lives in the plateau region.

Plateau

5Write a note about the following.

(a) Evaporation

Evaporation is the process in which water changes into water vapour because of the heat of the Sun. Water from the ground and oceans enters the atmosphere in the form of vapour. Evaporation is an important part of the water cycle.

(b) Condensation

Condensation is the process in which water vapour cools and changes into liquid water. It helps form clouds and is an important part of the water cycle.

(c) The water cycle

1. Evaporation: Water on the Earth evaporates continuously because of the heat of the Sun. Water that has entered the soil also evaporates and enters the atmosphere.

2. Condensation: Water vapour rises high into the atmosphere. As it rises, it cools and condenses into very fine droplets of water. These droplets float in the atmosphere and form clouds. When they join together to form bigger, heavier drops, they fall to the Earth as rain.

3. Collection and flow: Rainwater flows into rills, streams and rivers and finally reaches the sea. Ice in snow-covered regions also melts because of the heat of the Sun and flows into rivers.

4. Continuous cycle: Evaporation, condensation and rainfall continue again and again. This continuous process is called the water cycle.

6Give two examples of each.

Category	Examples
(a) Weather-related events	Rainfall, Snowfall
(b) Sources of water	Well, River

7Draw a labelled diagram showing the water cycle.

Labelled diagram showing evaporation, condensation, rainfall and collection in the water cycle.

3. The Earth and its Living World

Exercise