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Rajasthan Board Class 10 (RBSE) Our Environment — practice questions

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

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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.

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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.

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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.

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More Science topics

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