Our Environment

CBSE Class 10 Science · every board question from this chapter, 2022–2026

• Given below are some of the statements regarding our environment: (i) Change in our life-styles have resulted in greater amounts…2026
• An ecosystem contains maximum number of:2026
• Organisms of a higher trophic level which feed on several types of organisms belonging to a lower trophic level form the:2026
• Select the incorrect statement from the following:2026
• In accumulation of toxic substances at higher trophic levels of an ecosystem through the food chain, which of the following…2026
• In terms of various trophic levels of a food chain, which of the following organisms belong to the same level?2026
• In the given figure, identify the trophic level having maximum concentration of harmful chemicals.2026
• Which of the following is a non-biodegradable pollutant?2026
• Which of the following group is not 'biodegradable'?2026
• In an ecosystem, the decomposers perform an important role. Select the option indicating the role of decomposers.2026
• Which of the following limits the number of trophic levels in a food chain?2026
• Assertion (A): Ozone (O_3) gas at higher levels of atmosphere is a product of UV radiation acting on Oxygen (O_2). Reason (R):…2026
• Assertion: Ozone at higher levels of atmosphere is a product of UV radiation acting on oxygen molecule. Reason (R): The higher…2026
• Assertion: There are generally a greater number of individuals at the lower trophic levels of an ecosystem. Reason (R): The…2026
• Assertion: Highest percentage of pesticides is found in tertiary consumers in a food chain. Reason (R): Chemicals / pesticides…2026
• What are decomposers? List two important roles they play in the environment.2026
• (i) Chlorofluorocarbons (CFCs) have been linked to depletion of ozone layer. In 1987, the United Nations Environment Programme…2026
• Explain why food chains generally consist of three or four steps.2026
• Suggest one best way to dispose of the following wastes: (i) Kitchen waste (ii) Metallic waste (iii) Plastic bottles (iv)…2026
• In the following food chain, 5 J of energy is available to man. Calculate, how much energy was available at the producer level.…2026
• Explain the role of UV radiation in the formation of ozone layer. Why is UV radiation considered as highly damaging to organisms?2026
• Suggest two ways of dealing with waste generated at home.2026
• Give differences between the following: Sensory nerve and motor nerve Consumers and decomposers2026
• Given below is a pyramid showing various trophic levels in an ecosystem: From the organisms listed below, identify which one is…2026
• Mention any one harmful effect of using plastic bags on the environment. Suggest better alternatives to the usage of plastic…2026
• The examples of natural and manmade (artificial) ecosystems are respectively2025
• Which of the following groups do not constitute a food chain? (i) Wolf, rabbit, grass, lion (ii) Plankton, man, grasshopper, fish…2025
• In the following groups of wastes, which group contains only non- biodegradable wastes?2025
• Consider the following food chain: Grass → Grasshopper → Frog → Snake → Eagle If the amount of energy available at third trophic…2025
• In the food chains given below. Select the most efficient food chain in terms of energy:2025
• Other than the abiotic components, which of the given biotic components are not required to make an aquarium with small…2025
• Which one of the following gets biomagnified at different levels in a food chain?2025
• Identify from the following a group containing all non-biodegradable substances.2025
• The incorrect statement about ozone is2025
• Green plants occupy the first trophic level in every food chain because they2025
• Human activities that are affecting the environment are:2025
• Assertion: The amount of ozone in the atmosphere began to drop sharply in the 1980s. Reason (R): The oxygen atoms combine with…2025
• Assertion (A): Use of jute bags for shopping reduces pollution. Reason (R): Jute is biodegradable and its bag may be reused as…2025
• Assertion: Food web is a network of several food chains operating in an ecosystem. Reason (R): Food web decreases the stability…2025
• A gas 'X' is found in the upper layer of atmosphere. It is a deadly poison, but still essential for all life forms on earth.…2025
• Study the food web given below: Identify the food chain(s) in which the eagle receives the highest energy from the producers.…2025
• Why are the organisms of first trophic level important in any food chain? Justify the following statement: 'The flow of energy in…2025
• "Excessive use of chemicals and pesticides in agriculture adversely effect the environment." Justify this statement.2025
• Indicate the flow of energy in a food chain operating in an ecosystem. Why is it uni-directional? Give reason.2025
• We do not clean natural ponds or lakes whereas an aquarium or a swimming pool needs to be cleaned regularly. Why?2025
• Some harmful chemicals get accumulated in human bodies through the food chain. Name this phenomenon. Explain the reason of…2025
• Write the essential function performed by ozone at the higher levels of the atmosphere. How is it formed in the upper atmosphere?…2025
• "In a food chain energy flow is unidirectional." Give two reasons for the given statement. If 10,000 J energy is available at the…2025
• What are decomposers? Give two examples. State how they maintain a balance in an ecosystem.2025
• A food chain will be more advantageous in terms of energy if it has2024
• Identify the food chain in which the organisms of the second trophic level are missing:2024
• Consider the following statements about ozone: Ozone is poisonous gas. Ozone shields the earth's surface from the infrared…2024
• Some wastes are given below: (i) Garden waste (ii) Ball point pen refills (iii) Empty medicine bottles made of glass (iv) Peels…2024
• Which one of the following is not a natural ecosystem?2024
• Assertion: Accumulation of harmful chemicals is maximum in the organisms at the highest trophic level of a food chain. Reason…2024
• Assertion: Producers are capable of using light energy from the sun to make food available in an ecosystem. Reason (R): All food…2024
• Assertion: Ozone layer protects the surface of the Earth from harmful UV radiations. Reason (R): Chlorofluorocarbons (CFCs) are…2024
• Assertion: Oxygen is essential for all aerobic forms of life. Reason (R): Free oxygen atoms combine with molecular oxygen to form…2024
• Assertion: Green plants trap only 1\% of the energy of sunlight that falls on their leaves. Reason (R): All green plants are the…2024
• Assertion: The waste we generate daily may be biodegradable or non-biodegradable. Reason (R): The waste generated, if not…2024
• Name the term used for the materials which cannot be broken down by biological processes. Give two ways by which they harm…2024
• What are decomposers? List two consequences of their absence in an ecosystem.2024
• Define the terms biodegradable and non-biodegradable substance. Classify the following items into these two categories:…2024
• Give reasons for the following: Food web is more stable than a food chain in an ecosystem. A food chain should not have more than…2024
• Use of pesticides to protect our crops affect organisms at various trophic levels especially human beings. Name the phenomenon…2024
• Plants → Deer → Lion In the given food chain, what will be the impact of removing all the organisms of second trophic level on…2024
• Differentiate between food chain and food web. In a food chain consisting of deer, grass and tiger, if the population of deer…2024
• Study the picture given below showing three food chains, and and answer the following questions: (i) Name the type of ecosystems…2024
• Differentiate between biodegradable and non-biodegradable wastes. We generate a lot of non-biodegradable wastes in our daily…2024
• Study the given figure of a Food web and identify the primary consumer in the food web:2023
• Assertion: The energy which passes to the herbivores does not come back to autotrophs. Reason (R): The flow of energy in a food…2023
• Assertion: An ecosystem consists of biotic components and abiotic components. Reason (R): Biotic and abiotic components play…2023
• List two reasons to show that the existence of decomposers is essential in an ecosystem.2023
• State two reasons why human-made materials like plastics persist for a long time in the environment.2023
• (i) State the essential function performed by ozone at the higher levels of the atmosphere. (ii) Why was there a sharp drop in…2023
• "Although gardens are created by man but they are considered to be an ecosystem. "Justify this statement.2023
• Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?2023
• What is the difference between biodegradable and non-biodegradable substances? List two methods of safe disposal of biodegradable…2023
• We do not clean ponds or lakes but an aquarium needs to be cleaned regularly. Why?2023
• Use of several pesticides which results in excessive accumulation of pesticides in rivers or ponds, is a matter of deep concern.…2023
• "Ozone, although a deadly poison, performs an essential function for the earth and its inhabitants." Explain.2023
• How do harmful chemicals get accumulated progressively at each trophic level in a food chain?2023
• In the following food chain, if 50 J of energy was available to the hawk, how much energy would have been present at the first…2023
• What is meant by trophic level? On an average, what percentage of energy is transferred to the second trophic level from the…2023
• Explain how some harmful chemicals enter our bodies through the food chain. Why is the concentration of these harmful chemicals…2023
• Write the percentage of (i) solar energy captured by the autotrophs and (ii) energy transferred from autotrophs to the next level…2023
• If a harmful chemical enters in a food chain comprising peacock, plants, rats and snakes, which of these organisms is likely to…2023
• (i) Why does a kitchen garden called an artificial ecosystem while a forest is considered to be a natural ecosystem? (ii) While…2023
• Write the percentage of (i) solar energy captured by the autotrophs and (ii) energy transferred from autotrophs to the next level…2023
• Write one difference between biodegradable and non-biodegradable wastes. List two impacts of each type of the accumulated waste…2023
• How is ozone formed in the higher levels of the atmosphere? "Damage to the ozone layer is a cause of concern." Justify this…2023
• Explain how some harmful chemicals enter our bodies through the food chain. Why is the concentration of these harmful chemicals…2023
• In the following food chain, only 2J of energy was available to the peacocks. How much energy would have been present in Grass?…2022
• Kulhads (disposable cups made of clay) and disposable paper cups both are used as an alternative for disposable plastic cups.…2022
• "The improvement in our lifestyle has led to the generation of large amount of waste material." List two reasons to justify this…2022
• In the following food chain, only 2J of energy was available to the peacocks. How much energy would have been present in Grass?…2022
• What is ozone? How is it formed in the upper layers of the Earth's atmosphere? How does ozone affect our ecosystem? OR (i) List…2022
• In the following food chain, only 2J of energy was available to the peacocks. How much energy would have been present in Grass?…2022
• What are human-made ecosystems? Give an example. Can a human-made ecosystem become a self-sustaining ecosystem? Give reason to…2022
• What are trophic levels? Why are autotrophs considered to be at the first trophic level of all food chains? State the reason for…2022
• What are decomposers? State the role of decomposers in the natural replenishment of the soil. Why are decomposers not helpful in…2022
• In 1987, the United Nations Environment Programme (UNEP) forged an agreement to freeze the production of a certain chemical to…2022
• Draw a diagram showing flow of energy from solar input to a food chain having four trophic levels in an eco system. List two…2022
• Name the group of organisms which form in the first trophic level of all food chains. Why are they called so? Why are the human…2022
• We do not clean ponds or lakes, but an aquarium needs to be cleaned regularly. Why? Why is ozone layer getting depleted at the…2022
• Explain the reason why in a food chain the number of individuals decreases as we move from lower trophic level to higher trophic…2022

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