Class 5 Science - Our Environment - CBSE Worksheets Solutions - 1

Q1: Multiple Choice Questions (MCQs).

(i) An ecosystem is made up of:
(a) Living organisms only
(b) Non-living things only
(c) Both living organisms and non-living things
(d) None of the above
Ans: (c)

An ecosystem is a community of living organisms (plants, animals, and microbes) interacting with one another and their non-living environment (air, water, and soil).

(ii) Which of the following is a biotic component of the environment?
(a) Soil
(b) Water
(c) Air
(d) Plants
Ans: (d)

Biotic components are the living organisms in an ecosystem. Plants are living organisms and are therefore a biotic component of the environment.

(iii) Which of the following is an abiotic component of the environment?
(a) Animals
(b) Sunlight
(c) Bacteria
(d) Fungi
Ans: (b)

Abiotic components are the non-living factors of an ecosystem. Sunlight is a non-living factor and is therefore an abiotic component of the environment.

(iv) The process by which green plants make their food is called:
(a) Respiration
(b) Photosynthesis
(c) Transpiration
(d) Decomposition
Ans: (b)

Photosynthesis is the process by which green plants convert sunlight, carbon dioxide, and water into glucose (food) and oxygen.

(v) Which of the following is not a natural resource?
(a) Water
(b) Soil
(c) Plastic
(d) Air
Ans: (c)

Natural resources are materials or substances that occur in nature and can be used for economic gain. Water, soil, and air are all natural resources, while plastic is a man-made material.

Q2: Fill in the blanks.

(i) The _____ is made up of living and non-living things.
(ii) _____ are natural resources that can be used again and again.
(iii) The _____ is the layer of the atmosphere closest to the Earth's surface.
(iv) The process of converting waste materials into new products is called _____.
(v) Plants release _____ into the atmosphere during the process of photosynthesis.
Ans: 
(i) environment
(ii) Renewable resources
(iii) troposphere
(iv) recycling
(v) oxygen

Q3: True or False.

(i) The environment consists only of living things.
(ii) Renewable resources can never be used up completely.
(iii) The ozone layer is found in the stratosphere.(iv) Burning fossil fuels does not contribute to air pollution.
(v) Cutting down trees helps in maintaining the balance of the ecosystem.
Ans: 
(i) False: The environment consists of both living (biotic) and non-living (abiotic) components.
(ii) True: Renewable resources can be replenished naturally and can be used again and again.
(iii) True: The ozone layer is found in the stratosphere, which is the second layer of the Earth's atmosphere.
(iv) False: Burning fossil fuels contributes to air pollution by releasing harmful gases and particulates into the atmosphere.
(v) False: Cutting down trees disrupts the balance of the ecosystem, as trees provide oxygen, absorb carbon dioxide, and provide a habitat for various species.

Q4: Match the column.

Ans:

Q5: Short Answer Questions.

(i) What is an ecosystem?
Ans: An ecosystem is a community of living organisms (plants, animals, and microbes) interacting with one another and their non-living environment (air, water, and soil).

(ii) Give an example of a biotic component and an abiotic component of the environment.
Ans: An example of a biotic component is a tree, and an example of an abiotic component is sunlight.

(iii) What is the role of decomposers in the environment?
Ans: Decomposers play a crucial role in the environment by breaking down dead plants and animals into simpler substances. This helps in recycling nutrients and maintaining soil fertility.

(iv) Why is it important to conserve natural resources?
Ans: It is essential to conserve natural resources because they provide us with the materials and energy needed for our survival and well-being. Moreover, conserving natural resources helps maintain a balance in the ecosystem and ensures the availability of resources for future generations.

(v) What is the difference between renewable and non-renewable resources?
Ans: Renewable resources are those resources that can be replenished naturally on a human timescale, such as sunlight, wind, and water. Non-renewable resources are those that cannot be replenished within a human timescale or are formed at a much slower rate than their consumption, such as fossil fuels (coal, oil, and natural gas) and minerals.