MCQ & Extra Questions: Nature's Treasures

Extra Questions 

Q1: What percentage of air is nitrogen?

Ans: 78%.

Q2: Name the gas in the air that is essential for human survival.

Ans: Oxygen.

Q3: What is the moving air called?

Ans: Wind.

Q4: What is the main source of energy for all living beings on Earth?

Ans: The Sun.

Q6: How do forests contribute to the conservation of soil?

Ans: Forests prevent soil erosion by their roots, which hold soil particles together and reduce the speed of flowing water and wind. Fallen leaves and other decaying plant matter add nutrients and organic matter to the soil, improving its fertility and structure.

Q7: Explain the importance of rainwater harvesting.

Ans: Rainwater harvesting collects and stores rainwater for later use. It reduces dependence on groundwater, helps recharge underground water sources, conserves water for dry periods and reduces surface runoff that can cause flooding and soil erosion.

Q8: Why are fossil fuels considered non-renewable resources?

Ans: Fossil fuels are formed from the remains of plants and animals over millions of years. Because they take such a long time to form and are used much faster than they are produced, they cannot be replenished within a human lifetime and will eventually run out.

Q9: What role do solar panels play in conserving natural resources?

Ans: Solar panels convert sunlight into electricity, reducing the need to burn fossil fuels. By producing clean energy, they help lower air pollution and decrease the consumption of non-renewable resources.

Q10: Describe the concept of renewable and non-renewable resources with examples.

Ans: Renewable resources are those that can be naturally replenished over a short time, for example solar energy, wind and water. Non-renewable resources cannot be replaced quickly because they take millions of years to form, for example coal, oil and natural gas.

Multiple Choice Questions

Q1: What is the role of trees in maintaining the quality of soil?
a) Trees absorb water from the soil.
b) Trees prevent soil erosion.
c) Trees harden the soil.
d) Trees deplete nutrients from the soil.
Ans: (b) Trees prevent soil erosion.

Explanation: The roots of trees hold the soil in place, preventing it from being washed or blown away. Trees also reduce surface runoff and add organic matter from fallen leaves, which helps to keep the soil fertile and stable.

Q2: What is the primary purpose of a windmill?
a) To make paper
b) To generate electricity and perform mechanical tasks
c) To grow crops
d) To create art
Ans: (b) To generate electricity and perform mechanical tasks

Explanation: Windmills use the energy of moving air to turn blades and create mechanical power. This power can be used directly for tasks such as grinding grain, or it can be converted to electricity by attaching a generator.

Q3: Which of the following is a renewable resource?
a) Coal
b) Oil
c) Solar energy
d) Natural gas
Ans: (c) Solar energy

Explanation: Solar energy comes from the Sun and is continuously available each day, so it can be replenished naturally. This makes it a renewable resource, unlike coal, oil and natural gas which take millions of years to form.

Q4: What is the role of earthworms in soil?
a) They cause soil erosion.
b) They make soil acidic.
c) They help in turning and loosening the soil.
d) They compact the soil.
Ans: (c) They help in turning and loosening the soil.

Explanation: Earthworms burrow through the soil, which aerates and loosens it. Their movement mixes organic matter into the soil and improves drainage and soil structure, helping plants to grow better.

Q6: What are stepwells used for?
a) Growing crops
b) Building houses
c) Generating electricity
d) Harvesting rainwater
Ans: (d) Harvesting rainwater

Explanation: Stepwells are traditional structures built to collect and store rainwater. They allow people to access stored water and can help recharge groundwater during dry seasons.

Q7: What is the main reason for the depletion of fossil fuels?
a) Overuse
b) Natural disasters
c) Solar radiation
d) Soil erosion
Ans: (a) Overuse

Explanation: Fossil fuels are being used faster than they are formed. Continuous and increasing consumption in industries, transport and power generation leads to rapid depletion of these non-renewable resources.

Q8: Which of the following contributes to air pollution?
a) Solar panels
b) Wind turbines
c) Burning of fossil fuels
d) Rainwater harvesting
Ans: (c) Burning of fossil fuels

Explanation: Burning fossil fuels releases gases such as carbon dioxide and sulfur dioxide into the air. These gases and other particles contribute to air pollution and can harm human health and the environment.

Q9: Which of the following is a non-renewable resource?
a) Wind energy
b) Solar energy
c) Coal
d) Biomass
Ans: (c) Coal

Explanation: Coal is formed over millions of years from ancient plant remains. Because it cannot be replaced within a human lifetime once used, it is classified as a non-renewable resource.

Q10: What percentage of air is composed of oxygen?
a) 10%
b) 21%
c) 30%
d) 78%
Ans: (b) 21%

Explanation: Oxygen makes up about 21% of the Earth's atmosphere. It is the second most abundant gas after nitrogen, which is about 78%.