Ecosystem
CBSE Class 12 Biology · every board question from this chapter, 2022–2026 · 23 of them repeated across years
- Observe the contents 1, 2, 3 and 4 of soil samples I, II and III shown in the graph. If the temperature and moisture of all soil…2026asked 3×
- Which of the following is not a functional unit of an ecosystem?2026asked 2×
- In an ecosystem, different species occupy different levels and vertical distribution of species is found. This is called.2026asked 2×
- Which of the following is not a component of detritus food chain?2026
- Which of the following is a secondary consumer?2026
- Every trophic level has a certain mass of living material at a particular time. What is it called?2026
- Match the items given in Column I with Column II and select the correct option.2026
- Which of the following ecosystem is most productive in terms of net primary productivity?2026
- The biomass available in plants for consumption by herbivores and decomposers, is called:2026
- Assertion: Ecosystems require a constant supply of energy to synthesize the molecules they require. Reason (R): This is to…2026asked 2×
- Assertion: Net Primary Productivity (NPP) is always less than Gross Primary Productivity (GPP). Reason (R): A portion of Gross…2026
- Assertion: In terrestrial ecosystem much larger fraction of energy flows through grazing food chain. Reason (R): Grazing food…2026asked 3×
- Assertion: The pyramid of biomass in a pond aquatic ecosystem is always inverted. Reason (R): The biomass of consumers like…2026asked 2×
- Given below is a pyramid found in an ecosystem, where each bar represents the standing crop available in the trophic level. (i)…2026asked 2×
- Differentiate between grazing food chain and detritus food chain. OR Ecological pyramids are widely accepted but they still have…2026asked 3×
- What is primary productivity? Why does it vary in different types of ecosystems? Why is the assimilation of energy at the…2026
- Below is shown a pond that represents a self-sustaining natural ecosystem with both biotic and abiotic components interacting in…2026asked 3×
- What type of ecological pyramid would be obtained with the following data? Primary producer =10 g Secondary consumer =120 g…2025
- Mohit performed an analysis of two different soil samples from two areas A and B. He recorded these results: Soil Sample A:…2025
- Read the passage given below and answer the question. Food chains 'P' and 'Q' form an interconnection. 'P' initiates with wheat…2025
- Study the table given below showing the relationship between organism, its trophic level and kind of food chain it belongs to.…2025
- How is the interaction between Ophrys and its specific bee pollinator one of the best examples of co-evolution? Explain. OR…2025asked 3×
- Student to attempt either option- or: Analyse the following ecosystems and discuss, which will be more productive in terms of…2025asked 3×
- Student to attempt either option or. Identify the type of pyramid given below and write two identifying features of such a…2025
- Explain how the interaction between sea anemone and clownfish is one of the best examples of commensalism in nature. OR Correctly…2025asked 3×
- Student to attempt either option or. Construct a pyramid of biomass starting with phytoplankton, label its three trophic levels.…2025
- Explain how the interaction between a fig tree and its tight one-to-one relationship with the pollinator species of wasp is one…2025asked 3×
- State the conclusions derived by David Tilman's long term ecosystem experiments using outdoor plots.2025
- Name the type of food chains responsible for the flow of larger fraction of energy in an aquatic ecosystem and a terrestrial…2025asked 3×
- Which one of the following is not a characteristic feature of "humus" that is formed during decomposition of detritus?2024
- The rate of formation of new organic matter by consumers, and the biomass available for consumption of herbivores as well as…2024
- The organism that occupies more than one trophic level in a pond ecosystem is:2024
- The pyramid of biomass in sea is generally inverted because in sea:2024asked 3×
- Assertion: Some aquatic ecosystems have inverted biomass pyramids. Reason (R): More energy is required by the organisms occupying…2024asked 3×
- Study the diagram of a pyramid of biomass given below. Name the two standing crops that could be occupying level 'A' and level…2024
- Differentiate between grazing food chain and detritus food chain. OR Explain Brood parasitism with the help of a suitable example.2024asked 3×
- Study the diagram of a pyramid of biomass given below. Name the two standing crops that could be occupying level 'A' and level…2024
- Write important features of 'humus' formed during the decomposition cycle in a terrestrial ecosystem. OR (i) Graphically…2024asked 3×
- How is the rate of decomposition affected by the nature of detritus and temperature?2024asked 3×
- How is the grazing food chain different from the detritus food chain? "The detritus food chain may be connected to the grazing…2024
- Construct a pyramid of biomass in sea with phytoplankton and fishes. Explain giving reasons about the characteristic of the…2024
- State what is primary productivity and mention its units. 1 1/2 Some ecologists observed that primary productivity of a place in…2024
- The primary productivity in an ecosystem is expressed as:2023asked 3×
- Given below is a diagram of an ecological pyramid of numbers. Choose the correct food chain from the list of food chains given,…2023
- Assertion: Decomposition process is slower if detritus is rich in lignin and cutin. Reason (R): Decomposition is largely an…2023asked 3×
- Given below is a food web that involves nine organisms. Identify two producers and two carnivores shown in the food web. Is it…2023asked 3×
- Ecological pyramids give important information about the ecological system, but do have some limitations. List any two…2023
- Plants capture only 2-10 percent of the photosynthetically active radiation of the Sun and this small amount of energy is able to…2023
- Observe the schematic representation given above and answer the following questions: (i) Identify A and B. (ii) Calculate the…2022
- Observe the schematic representation given above and answer the following questions: (i) Identify A and B. (ii) Calculate the…2022asked 2×
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