About Nature
All things, including humans, animals, plants, air, water and soil, are parts of Mother Nature. All of us depend on each other for our survival and growth. Living things and non living things interact with each per their needs. We make many things using natural materials. This way, living things and non-living things depend on each other. Nature provides enough for our needs. It is our responsibility to preserve natural resources and use them judiciously.
Importance of Natural Resources
Question 1:
Why Are Plants Important?
Answers:
Plants are important due to the following reasons—
- They provide us oxygen while performing photosynthesis.
- They help in maintaining the temperature of the environment.
- Plants help in bringing rain.
- They are a habitat for many animals and birds.
- Plants provide us with the food we eat.
Question 2:
Is Air a Mixture of Gases? How Is the Level of Oxygen Maintained in the Air?
Answers:
Plants are important due to the following reasons—
- Yes, air is a mixture of different gases surrounding the Earth.
- While performing photosynthesis, plants use carbon dioxide in the air and release oxygen.
- It happens during the day in the presence of the Sun. At night, plants take in oxygen and release carbon dioxide.
- Hence, plants maintain the level of oxygen in the air by photosynthesis.
Question 3:
Is Air a Mixture of Gases? How Is the Level of Oxygen Maintained in the Air?
Answers:
- Life on the Earth depends upon the light it receives from the Sun.
- Plants depend on sunlight to carry out photosynthesis.
- Sunlight maintains an optimum temperature on the Earth.
- In the absence of sunlight, there would be no vegetation, which would also severely affect the animal world.
- Sunlight is vital for the continuity of life on Earth.
Question 4:
How Is Soil Formed?
Answers:
- The process of weathering forms soil that constitutes the topmost layer of the Earth..
- Weathering takes place through natural forces like water and wind.
- Also, small plants like lichen help in weathering by loosening up rocks.
Question 5:
What Gives Colours to the Soils of Different Places?
Answers:
The characteristic colour of soil is because of the following reasons—
- Age of the soil.
- Presence of minerals; the red colour is due to iron, and the white colour is due to salts and silicates.
- Amount of organic matter in soil.
Man-made Things
Question 1:
How Are Man-Made Things Prepared Using Natural Things?
Answers:
- Natural things are used as raw materials for making various things around us.
- Petrol and diesel used in vehicles are products made from crude oil during its purification.
- The furniture we use is made using wood from trees.
- Products like paints and grease are made using the chemicals obtained during the purification of petroleum.
- Iron is obtained from natural minerals.
Question 2:
Why Are Specific Raw Materials Used to Make Different Man-Made Things?
Answers:
- Each natural material has a particular property required to make specific man-made things.
- For example, soil can be a cheap and readily available resource to make clay for pottery.
- Wood has cellulose fibres that are essential for making paper. Therefore, wood is used to make paper.
Living Things and Non-living Things
Question 1:
Robots Can Walk, Dance, Sing, Speak, and Even Think, So Are They Living or Non-living Things?
Answers:
- Robots can do many human activities nowadays. But they are made using non-living things such as plastic, metals, glass, etc.
- Robots can think and perform different activities based on their programming, using a set of instructions.
- They do not require food, water and air to survive; they cannot reproduce; hence they are non-living things.
Question 2:
Why Do Chalks Break Into Pieces, but the Metal Wires Get Bent When We Try to Bend Them?
Answers:
- Specific properties of non-living things make them unique.
- The material with which chalk is made, i.e., limestone, is fragile and soft and can be converted into powder if scratched.
- On the other hand, the material of wires (copper, aluminium, etc.) is flexible.
- Such materials cannot break even if hammered but change their shape to form a wire or sheet.
Question 3:
Wouldn’t It Be Great to Have No Insects Like Mosquitoes or Cockroaches Anywhere?
Do You Agree or Disagree With This Fact?
Answers:
- Many insects are harmful to us as they destroy food, clothes, etc.
- However, they are part of food chains that prevail in the ecosystem. Some other animal species in our ecosystem will be affected if they do not exist.
- Moreover, silkworms, honeybees and lac insects are beneficial for humans as they secrete essential substances.
Question 4:
Do All Plants Make Their Food?
Answers:
- Most plants appear green because chlorophyll gives them their characteristic colour. They make their food using a green pigment called chlorophyll, water, minerals and sunlight.
- Some non-green plants, like mushrooms, do not perform photosynthesis due to the lack of chlorophyll.
- Some plants like pitcher plants and Venus fly trap partially fulfil their nutritional demands by ingesting insects.
Question 5:
Birds Lay Eggs to Reproduce While Few Animals Give Birth to Young Ones. How Does Reproduction Take Place in Plants?
Answers:
- Plants reproduce by forming seeds inside the fruits.
- Fruits are matured flowers.
- These seeds germinate to grow into a new plant.