Class 10 Science Chapter 13: Our Environment — 3 Marker Important Questions
Practice Our Environment 3 Marker important questions and mock-test sets for CBSE revision.
Topic-wise important and practice questions
Review question distribution across chapter topics for 3 Mark questions.
| Topic | 3 Mark |
|---|---|
| Biodegradable Substances | 5 |
| Food Chains and Trophic Levels | 3 |
| Non-Biodegradable Substances | 2 |
| Environmental Effects of Biodegradable Waste | 2 |
| Natural and Human-Made Ecosystems | 2 |
| CFCs and Ozone Depletion | 2 |
| Ecosystem: Biotic and Abiotic Components | 0 |
| Limits on Food-Chain Length | 2 |
| Ozone Layer and UV Protection | 3 |
| Waste Segregation and Local Waste Management | 3 |
| Biological Magnification | 1 |
| Environment-Friendly Practices | 2 |
| Food Webs and Interdependence | 2 |
| International Action on Ozone-Depleting Substances | 2 |
| Removing a Trophic Level and Ecosystem Balance | 2 |
| Producers and Photosynthetic Autotrophs | 1 |
| Trophic Position and Pollutant Concentration | 2 |
| Environmental Effects of Non-Biodegradable Waste | 1 |
| Enzyme Specificity and Biodegradability | 2 |
| Formation of Ozone in the Upper Atmosphere | 0 |
| Lifestyle, Disposable Materials and Waste Generation | 3 |
| Unidirectional Flow of Energy | 1 |
| Decomposers and Nutrient Recycling | 1 |
| Energy Capture by Producers | 2 |
| Entry of Pesticides into Food Chains | 1 |
| Consumers: Herbivores, Carnivores, Omnivores and Parasites | 1 |
| Ten Percent Law of Energy Transfer | 2 |
3 Marker Preparation & Exam Strategy
3 Mark questions evaluate conceptual depth, multi-step problem solving, diagram explanations, and cause-effect reasoning.
- Organize responses into three well-defined points or three logical reasoning steps.
- Support answers with neat labeled diagrams, chemical equations, or relevant citations where applicable.
- State intermediate values and units clearly in multi-step derivations or numerical problems.
Sample Questions
Q1. Describe the principle, working, or main process in Our Environment with the help of a labeled diagram.
Model Answer: Provide the governing principle, concise step-by-step description, and neat schematic representation with key labels.
Q2. Derive or explain the relationship between quantities involved in Our Environment.
Model Answer: State initial assumptions, apply governing laws, and show logical progression to the final expression.
Q3. Analyze a scenario or numerical problem based on Our Environment and calculate the required outcome.
Model Answer: List given parameters, apply the governing relationship, and state the final result with appropriate units.