Start learning →

Bihar Board Class 10 (BSEB) Our Environment — practice questions

Explore 33 free Our Environment questions in Bihar Board Class 10 (BSEB) Science. Open each question or exercise to read its content, reference answers and available explanation.

Practise Our Environment with Quill →

Our Environment questions and exercises with answers

Showing questions 1–30 of 33.

Which of the following is a DECOMPOSER in a typical ecosystem?Read the answer and worked solution →The ozone layer protects life on Earth by:Read the answer and worked solution →Which of the following is BIODEGRADABLE waste?Read the answer and worked solution →The principle of '3 R's' for environmental conservation refers to:Read the answer and worked solution →An ecosystem consists of:Read the answer and worked solution →Organisms that produce their own food using sunlight are called:Read the answer and worked solution →Decomposers help in the ecosystem by:Read the answer and worked solution →The 10% law of energy transfer states that:Read the answer and worked solution →In a typical food chain "grass → grasshopper → frog → snake", the frog is at the:Read the answer and worked solution →The flow of energy in an ecosystem is:Read the answer and worked solution →Ozone in the stratosphere is important because:Read the answer and worked solution →Stratospheric ozone is formed by the action of UV radiation on:Read the answer and worked solution →Chlorofluorocarbons (CFCs) damage the ozone layer because they:Read the answer and worked solution →The Montreal Protocol (1987) aimed at:Read the answer and worked solution →A substance broken down by biological processes is:Read the answer and worked solution →Which of the following is non-biodegradable?Read the answer and worked solution →A food web is best described as:Read the answer and worked solution →In any ecosystem, the largest population in numbers usually belongs to the:Read the answer and worked solution →The phenomenon by which non-biodegradable chemicals get progressively concentrated up the food chain is called:Read the answer and worked solution →The ozone "hole" first widely reported in the 1980s was located over:Read the answer and worked solution →A pond ecosystem provides examples of all of the following EXCEPT:Read the answer and worked solution →Why do food chains rarely have more than four or five trophic levels?Read the answer and worked solution →In which form is energy lost as it moves up the trophic levels?Read the answer and worked solution →Which gas is produced in the largest quantity by anaerobic decomposition of organic waste in landfills?Read the answer and worked solution →Ozone (O₃) at ground level is:Read the answer and worked solution →Which is the simplest correct food chain in a grassland ecosystem?Read the answer and worked solution →Increased UV radiation due to ozone depletion can cause:Read the answer and worked solution →Which group of organisms recycles nutrients in an ecosystem?Read the answer and worked solution →Composting kitchen waste at home contributes to:Read the answer and worked solution →The Tyndall effect in air refers to scattering of light by:Read the answer and worked solution →

Worked practice questions

Which of the following is a DECOMPOSER in a typical ecosystem?

  1. Tiger in a forest food chain ecosystem
  2. Mango tree in a garden ecosystem
  3. Bacteria breaking dead leaves in soil
  4. Wheat plant in a Punjab field farm
Show answer and solution

Correct answer: C. Bacteria breaking dead leaves in soil

Decomposers break down dead organic matter into simple compounds, recycling nutrients to soil. Bacteria and fungi are the main decomposers.

Open this question →

The ozone layer protects life on Earth by:

  1. Reflecting visible sunlight back into space at noon
  2. Holding Earth's heat through the greenhouse effect
  3. Generating breathable oxygen continuously each day
  4. Blocking harmful UV-B and UV-C radiation from the Sun
Show answer and solution

Correct answer: D. Blocking harmful UV-B and UV-C radiation from the Sun

Ozone in the stratosphere blocks harmful UV-B and UV-C radiation. Without it, skin cancer, cataracts, and ecological damage would surge.

Open this question →

Which of the following is BIODEGRADABLE waste?

  1. Plastic bags and disposable bottles
  2. Glass containers and aluminium cans
  3. Vegetable peels and dry tree leaves
  4. Mercury-bearing batteries and CFL lamps
Show answer and solution

Correct answer: C. Vegetable peels and dry tree leaves

Biodegradable waste is broken down by microorganisms: vegetable peels, tree leaves, paper, cloth, kitchen waste. Plastic, glass, metals and batteries are non-biodegradable.

Open this question →

How to practise

  1. Choose a Our Environment question and try to work out your answer.
  2. Open the question to check the correct answer and read its worked solution.
  3. Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.

More Science topics

Light - Reflection and RefractionLife ProcessesScienceChemical Reactions and EquationsThe Human Eye and the Colourful WorldElectricityCarbon and its CompoundsMetals and Non-metals