Our Environment - 1 Class 3 Worksheet Science

Q1: Multiple Choice Questions (MCQs)

(i) Which of these is not a part of the environment of a fish?
(a) Trees
(b) Water
(c) Underwater plants
(d) Water insects
Ans: (a)
Fish live in water and have nothing to do with trees.

(ii) Which of the following is a non-living part of the environment?
(a) Animals
(b) Birds
(c) Soil
(d) Plants
Ans: (c)
The non-living components of the environment are known as abiotic factors. Abiotic factors include things such as rocks, water, soil, light, rocks etc.

(iii) Plants depend on animals for
(a) food
(b) carbon dioxide
(c) oxygen
(d) shelter
Ans: (b)
Plants depend upon animals for pollination, Seed dispersal and Carbon dioxide.

(iv) Animals depend on plants for
(a) food
(b) oxygen
(c) shelter
(d) all of these
Ans: (d)
Animals are consumers and they all depend on plants for survival. Some eat plants directly, while others eat animals that eat the plants. In turn, some plants depend on animals to help spread their seed. Decomposing animal carcasses can also provide nutrients for plants to grow.

Q2: True & False

(i) Our body is made up of 70% of water.
(ii) Fertile soil supports rich variety of plants.
(iii) Birds and animals help plants to reproduce.
(iv) Sunlight gives warmth to plants only.
(v) Our environment includes only living organisms and not non-living elements.
Ans:
(i) True
(ii) True
(iii) True
(iv) False
(v) False

Q3: Fill in the Blanks

(i) Our environment includes __________ living and non-living elements.
Ans: all

(ii) __________ from factories and motor cars can disturb the environment.
Ans: Smoke

(iii) Excessive noise can harm the __________ of living beings.
Ans: health

(iv) Environment has a __________ level in every area.
Ans: tolerance

(v) Tree plantation improves the environment by increasing __________ cover.
Ans: green

Q4: Answer the following questions in brief.

(i) Explain why excessive noise pollution is harmful to both humans and animals.
Ans: Excessive noise pollution can cause stress, hearing problems, and other health issues in humans. It can also disrupt animal behavior, affecting their feeding, mating, and communication patterns. Continuous exposure to high noise levels can lead to chronic health problems and disturb the overall well-being of both humans and animals.

(ii) Describe one activity that can improve the environment and its impact on the surroundings.
Ans: Tree plantation is an activity that can significantly improve the environment. Trees absorb carbon dioxide, provide oxygen, and offer habitat to various organisms. They also prevent soil erosion and enhance biodiversity. Tree plantation helps combat climate change and creates a healthier and more balanced environment for both humans and wildlife.

(iii) What is the significance of recognizing the tolerance level of the environment?
Ans: Understanding the tolerance level of the environment is crucial because it indicates the maximum stress or disturbance it can endure without suffering significant harm. By recognizing this limit, humans can make informed decisions about their activities and strive to keep environmental factors within acceptable limits. This knowledge guides environmental conservation efforts and sustainable practices, ensuring the well-being of both nature and living beings.

(iv) Explain why controlling the use of insecticides and pesticides is essential for maintaining a healthy environment.
Ans: Insecticides and pesticides, while intended to control pests, can harm non-target organisms, including beneficial insects, birds, and aquatic life. Their excessive use can disrupt ecosystems and lead to the decline of natural predators, upsetting the balance in nature. Controlling their use is essential to prevent environmental pollution, protect biodiversity, and maintain a healthy environment. Integrated pest management techniques can offer effective alternatives, minimizing the adverse impact on the ecosystem.