CLASS 10 SCIENCE • THE INTERACTIVE ECOSYSTEM LAB
Our Environment Class 10 Worksheet
with Online Quiz and Activities
Build a food chain, trace energy and explore the connections that keep ecosystems functioning. Learn trophic levels, decomposition, biomagnification, ozone and waste through diagrams and practical reasoning.
Build the Connections
Arrange feeding pathways and connect organisms with their roles.
◎Explore the Ecosystem
Change energy inputs, inspect web routes and compare environmental conditions.
✓Explain the Evidence
Calculate energy and distinguish scientific conclusions from assumptions.
Our Environment Class 10 Online Quiz
Question 1 / 20 • Easy
Which is a biotic component of a pond?
Choose an answer to continue, or use the question numbers.
Quiz instructions
Answer 10 easy, five average and five HOTS questions in 20 minutes. The timer starts with your first answer or question-navigation action. Choosing an answer advances except at the final question. Review using Previous or the numbered buttons. One mark per correct answer, no negative marking. Submission or timeout reveals the score and every explanation. Restart clears answers and pauses the timer.
Interactive Ecosystem Food Chain and Waste Games
Choose a game from the raised selector. The topic, challenge and controls share one frame.
Ecosystem Diagram Detective
Choose the labelled feature matching the function or category.
Find the non-living energy input shown in the diagram.
Energy Food Web Decomposition and Ozone Activities
Select a lab, change a setting and check each of its five missions.
How to use these environment models
Five games, five labs and five extra-practice sets provide 75 tasks, separate from the quiz. Games and labs share one active main workspace; extra practice is independent. Entries remain while this page stays open. The energy model uses 10% transfer. The food web tests connectivity, not population growth. Decomposition is qualitative. Pollutant indices are invented teaching values, and the ozone explorer compares explanations rather than predicting real-time chemistry.
Our Environment Class 10 Extra Questions and Numericals
10% Law Numericals
Use the textbook 10% transfer model. Given producer energy is not incident solar energy.
Producers contain 15000 J. Find energy at primary and secondary consumers.
Write the known values, select a relationship and use consistent units. Check the requested unit in each field.
Accepts fractions or rounding to two decimal places. Tolerance ±0.0051 in the stated units.
Eight Revision Tips for Students
- Start trophic-level counting with the producer.
- Read a food-chain arrow as resource to consumer.
- Count transfers before applying the 10% rule.
- Keep sunlight capture separate from trophic transfer.
- Distinguish nutrient cycling from energy flow.
- Separate biomagnification from the energy percentage rule.
- Do not confuse recycling with biodegradation.
- State assumptions before predicting ecosystem changes.
Five Teaching Tips for Parents and Teachers
- Ask students to explain every arrow in a chain.
- Use an omnivore to compare pathway-dependent trophic roles.
- Compare forward and reverse energy calculations.
- Discuss why a connection model cannot predict exact populations.
- Use dated ozone news to distinguish annual variation from long-term trends.
Our Environment Class 10 Notes Important Questions and Solved Examples
Where does energy go when a grasshopper eats grass? Why can a pollutant become more concentrated in a predator? Why is ozone useful high in the atmosphere but harmful near the ground? This Our Environment Class 10 worksheet connects these questions with food-chain diagrams, an online quiz and interactive activities. Attempt the written worksheet independently and use the explanations to improve the reasoning behind your answers.
This guide includes Our Environment Class 10 short notes, ecosystem components, food chains and food webs, trophic levels, the 10 percent law, biological magnification, decomposers, ozone depletion and waste management. It also includes worked energy numericals, extra questions with answers, case-based questions and common mistakes.
Our Environment Class 10 Summary
An ecosystem includes interacting organisms and the non-living conditions around them. Producers make organic food, consumers obtain food from other organisms, and decomposers break down organic remains and wastes. Matter can be reused through nutrient cycles, while energy flows through feeding relationships and is progressively dissipated.
The chapter also asks how human activities affect these systems. Persistent pollutants can move through food webs, waste can accumulate when it is poorly managed, and chemicals can affect the protective stratospheric ozone layer. Explain the mechanism in each case rather than treating every environmental problem as the same process.
Ecosystem Class 10 Biotic and Abiotic Components
Biotic components are living organisms such as plants, animals, fungi and bacteria. Abiotic components include light, water, temperature, air and soil conditions. A pond, forest, garden or aquarium can be studied as an ecosystem, although an aquarium often depends on human inputs and maintenance.
| Group | Role | Example |
|---|---|---|
| Producers | Make organic food from inorganic materials. | Photosynthetic plants and algae. |
| Consumers | Obtain food by feeding on other organisms or their products. | Herbivores, carnivores and omnivores. |
| Decomposers | Break down dead organic material and wastes. | Many bacteria and fungi. |
Common question Is sunlight a producer? No. It is an abiotic energy input. Producers are organisms that store energy in organic matter. Similarly, an earthworm is living, while water temperature is an environmental condition.
Food Chain and Food Web Class 10 with Examples
A food chain is one sequence of feeding relationships. In the example grass → grasshopper → frog → snake, the arrow points from the organism being eaten to the organism that eats it. It represents the direction in which energy and material pass through feeding.
A food web connects several chains. An animal can have more than one food source or predator, so the web often represents an ecosystem more realistically. The web diagram below has one route through insects, frogs and snakes and another through rabbits. Both can lead towards the hawk.
What happens if one organism is removed? Some routes can be interrupted while others remain. However, a connection diagram alone does not provide exact future population sizes. Growth, competition, disease, alternative foods and other environmental conditions also matter. The interactive web is therefore labelled a connectivity model, not a population forecast.
Trophic Levels Class 10 and Consumer Positions
| Organism in the example | Feeding role | Trophic level |
|---|---|---|
| Grass | Producer | First |
| Grasshopper eating grass | Primary consumer | Second |
| Frog eating the grasshopper | Secondary consumer | Third |
| Snake eating the frog | Tertiary consumer | Fourth |
Primary consumer and first trophic level are not the same. Producers occupy level one, so primary consumers occupy level two. Count from the producer rather than starting at the first animal.
An omnivore can occupy different positions in different pathways. A bird eating grain acts as a primary consumer, while the same bird eating a plant-eating insect acts as a secondary consumer. Its feeding role depends on the stated relationship.
10 Percent Law of Energy Transfer Class 10
The textbook model estimates that about 10% of the energy available at one trophic level becomes available at the next. Organisms use energy in life processes, and not all biomass is eaten or assimilated. Much energy is eventually dissipated as heat. Actual transfer efficiencies vary; 10% is a useful classroom approximation rather than an exact universal measurement.
For these questions, energy at level n = producer energy × (0.1)n − 1. Going forward one transfer means multiplying by 0.1. Going backwards one transfer means multiplying by 10. The number of transfers from producers is one less than the trophic-level number.
Important starting-point check Energy arriving as sunlight is not the same as energy already stored in producers. The 10% trophic-transfer rule does not itself specify the photosynthetic capture of sunlight. If a question gives incident solar energy and a capture efficiency, apply that separate step first.
Our Environment Class 10 Numericals with Solutions
Example 1 - calculate energy at successive levels
Producers contain 30000 J. Estimate primary-, secondary- and tertiary-consumer energy.
Primary consumers = 30000 × 0.1 = 3000 J.
Secondary consumers = 3000 × 0.1 = 300 J.
Tertiary consumers = 300 × 0.1 = 30 J.
Three transfers separate producers from tertiary consumers.
Example 2 - work backwards from level four
The fourth trophic level contains 5 kJ. Estimate producer energy.
Fourth to third level = 5 × 10 = 50 kJ.
Third to second level = 50 × 10 = 500 kJ.
Second to first level = 500 × 10 = 5000 kJ.
Keep the unit kJ consistent throughout.
Example 3 - keep sunlight capture separate
Suppose a question explicitly states that producers capture 1% of 200000 J of incoming light energy. Use the stated 10% model for the next transfer.
Producer energy = 200000 × 0.01 = 2000 J.
Primary-consumer energy = 2000 × 0.1 = 200 J.
The assumed 1% capture is given for this problem. It is not the trophic-transfer percentage.
Why Are Food Chains Usually Short?
Less energy is available at each successive trophic level. This limits the energy that can support later consumers, so many textbook chains have only a few levels. Do not turn this into a rule that no real food chain can ever have more than four organisms. The available energy, ecosystem conditions and actual feeding relationships determine what can be supported.
Role of Decomposers in an Ecosystem
Many bacteria and fungi break down dead organic matter and wastes. This helps return nutrients to the surroundings so that producers can use available nutrients again. Decomposers receive organic material originating from several trophic levels; they do not belong only at the end of every chain.
Do decomposers recycle energy? They recycle matter through decomposition and nutrient return. They do not convert dissipated heat back into sunlight. Energy flows through the system, while nutrient atoms can be reused. Scavengers and detritivores may also process remains, but their feeding should not be confused with every aspect of microbial decomposition.
Biological Magnification Class 10 Explained
Biological magnification, or biomagnification, is an increase in the concentration of certain pollutants across successive feeding levels. A predator can consume many contaminated prey. If the substance persists and is retained rather than readily metabolised or eliminated, its concentration may become higher in upper consumers.
Bioaccumulation and biomagnification differ. Bioaccumulation concerns build-up within an organism over time; biomagnification concerns increasing concentration across feeding levels. Not every persistent or non-biodegradable material must biomagnify in every chain. Chemical properties, uptake, retention and feeding relationships matter.
The pollutant lab uses invented concentration indices and a chosen multiplier to make a possible trend visible. It is not a measured dataset. The 10% law concerns energy transfer and must not be used as a universal pollutant-concentration rule.
Biodegradable and Non-Biodegradable Waste Difference
| Feature | Biodegradable material | Not ordinarily biodegradable |
|---|---|---|
| Ordinary biological breakdown | Can be broken down by suitable organisms under suitable conditions. | Does not undergo ordinary microbial decomposition into compost on relevant timescales. |
| Examples | Vegetable peel, leaves, untreated cotton and plain paper. | Glass, metals and conventional plastics. |
| Management point | Suitable organic material may be composted appropriately. | Reuse, accepted recycling or appropriate collection may be needed. |
Recyclable does not mean biodegradable. Glass and aluminium can be recycled without being decomposed by ordinary compost microbes. Similarly, a material described as compostable may require particular facilities or conditions; it should not automatically be treated as harmless litter.
Is biodegradable waste always harmless? No. Large quantities or poor management can cause pollution, odour and other problems. Dryness can limit microbial activity; limited air can change the processes involved. A wet unmanaged pile is not automatically the same as a well-managed aerobic compost system.
Waste Management Reduce Reuse and Recycling
Preventing waste is often useful before treating it. Reduce avoidable packaging, reuse durable items, repair what can be repaired and separate materials for appropriate processing. Keep batteries, hazardous materials and sharp glass out of ordinary compost. Use the collection arrangements applicable to the material and location rather than assuming one bin-colour system works everywhere.
Recycling can recover materials, while composting can process suitable organic material. Neither process excuses wasteful consumption or indiscriminate mixing. A school waste audit can compare what is generated, what can be avoided and which streams need separate handling.
Ozone Layer Depletion Class 10
Ozone is O₃, a molecule containing three oxygen atoms. Stratospheric ozone absorbs part of the Sun’s ultraviolet radiation and helps protect living systems. This is different from ground-level ozone, which is an air pollutant. The same molecule’s environmental role depends on where it occurs.
Certain ozone-depleting substances, including CFCs, can release chlorine through atmospheric processes and contribute to ozone destruction. An ozone hole refers to severe thinning, especially seasonal Antarctic depletion, rather than an empty opening in the atmosphere. The Montreal Protocol coordinates international action to phase out ozone-depleting substances.
Ozone depletion is not identical to global warming. Some substances can affect both issues, but the mechanisms differ. HFCs do not directly deplete ozone, yet many are potent greenhouse gases. The Kigali Amendment addresses their phase-down within the Montreal Protocol framework.
Our Environment Important Questions with Answers
- Why are producers essential in the food chains studied here?
They store energy in organic food and provide a starting resource for consumers.
- Why do food-chain arrows point towards the consumer?
They indicate the direction of feeding-related energy and material transfer from resource to consumer.
- Why can top consumers have higher pollutant concentrations?
They may eat many contaminated prey and retain a substance that is not readily removed.
- What happens when decomposer activity is reduced?
Organic remains may accumulate and nutrient return can be affected. The exact outcome depends on the ecosystem.
- Why does one missing species not always destroy every web pathway?
Some consumers can have alternative feeding connections. The remaining routes need to be traced rather than assumed.
- Why is a smaller ozone hole in one year not proof of complete recovery?
Annual variability and long-term trends are different. Continued observations are needed to assess recovery.
Our Environment Class 10 Case-Based Questions and Solutions
A simplified pathway is algae → larvae → small fish → fish-eating bird.
Identify the fish’s role Secondary consumer, at the third trophic level.
Where could a biomagnifying pollutant be most concentrated? Potentially in the bird, provided the pollutant is taken up, retained and transferred through this pathway.
If producers have 12000 J, what is estimated for the bird? Three transfers give 12000 → 1200 → 120 → 12 J.
Should energy and pollutant concentration use the same rule? No. The energy model and pollutant behaviour describe different processes.
Assertion Decomposers support nutrient cycling. Reason Their activity helps return nutrients from organic remains to the surroundings. Both are true, and the reason explains the assertion.
Assertion Every recyclable material is biodegradable. Reason Recycling and microbial decomposition are different processes. The assertion is false and the reason is true.
Current CBSE Practice and Ozone Recovery Update
The CBSE Science syllabus for 2026–27 lists ecosystems, environmental problems, ozone depletion, waste and biodegradable/non-biodegradable substances. Questions 7, 9 and 14 of the official Science sample paper include trophic classification, energy-transfer reasoning, reverse energy calculation and pollutant concentration. These are verified sample-paper themes, not repeated-past-paper claims or predictions.
In its 16 September 2026 ozone update, WMO reported continued long-term recovery while noting year-to-year variability. Its discussion of a relatively small Antarctic ozone hole concerned observations from 2025, not proof that recovery was complete. This is a useful example of why publication date and observation year must be distinguished.
The UNEP World Ozone Day campaign also highlighted sustainable cooling and the Kigali Amendment. The classroom takeaway is to distinguish ozone protection from climate-warming mechanisms while recognising the role of coordinated environmental action.
Reference NCERT Our Environment. Reviewed 23 October 2026. Interactive questions are original practice material; no fixed chapter marks or guaranteed examination questions are claimed.
Related Class 10 Science Resources
Frequently Asked Questions
What is an ecosystem in Class 10 Science?
An ecosystem includes interacting living organisms and their non-living surroundings. Biotic organisms and abiotic conditions influence one another.
What is the difference between biotic and abiotic components?
Biotic components are living organisms, such as algae and fungi. Abiotic components are non-living factors such as sunlight, water and temperature.
What is the difference between a food chain and a food web?
A chain is one feeding pathway. A web connects several pathways and can show alternate food sources and predators. Arrows point from resource to consumer.
How do I identify trophic levels?
Start with producers at level one. Primary consumers are level two, secondary consumers level three and tertiary consumers level four. Use the stated feeding pathway.
How do I solve 10 percent law numericals?
Multiply by 0.1 for each forward trophic transfer or by 10 for each reverse transfer. Count transfers carefully and keep units consistent. Sunlight capture is a separate step if specified.
Why do food chains usually have few trophic levels?
Available energy declines through successive transfers. This limits the energy supporting later consumers. It is not a universal rule that every chain has exactly four levels.
Do decomposers recycle energy?
They help recycle nutrients from organic remains. Energy is transferred and dissipated; it does not return to the Sun through decomposition.
What is biological magnification?
It is increasing concentration of certain retained pollutants across feeding levels. Persistence, uptake and retention matter; not every non-biodegradable material necessarily biomagnifies.
Is every recyclable material biodegradable?
No. Glass and aluminium can be recycled but do not biodegrade in ordinary compost. Recycling and microbial decomposition are different processes.
Is biodegradable waste always harmless?
No. Quantity, disposal conditions and management matter. Large unmanaged accumulations can still create environmental problems.
Why is ozone useful in the stratosphere but harmful near the ground?
Stratospheric ozone helps absorb ultraviolet radiation. Ground-level ozone is an air pollutant. The molecule’s location changes its environmental role.
Which Our Environment questions appear in the current sample-paper themes?
The official paper includes trophic levels, the 10% model, reverse energy calculations and pesticide concentration in a chain. Practise both the calculation and its assumptions. These are sample-paper themes, not guaranteed future questions.
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