Class 10 • Biology • Chapter 13
Our Environment
True & False Quiz
Ecosystem. Food Web. Sustain.
✓True
✗False
25
Questions
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Ch.13
Chapter
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Class
Why True & False for Our Environment?
How this format sharpens your conceptual clarity
🔵 Environmental science connects ecology, conservation, and sustainability — directly relevant to climate change and global policy discussions.
✅ T/F tests the 10% energy rule, food chains vs webs, biodegradable vs non-biodegradable, and ozone layer depletion.
🎯 Only 10% of energy is transferred to the next trophic level — 90% is LOST as heat. This limits food chains to 3–4 levels.
📋
Read each statement carefully. Click True or False — instant feedback with explanation appears. Submit anytime; unattempted questions are marked Skipped.
Q 1
Environment includes only living things around us.
Q 2
An ecosystem is a self-sustaining unit formed by interaction of biotic and abiotic components.
Q 3
Producers occupy the first trophic level in any food chain.
Q 4
Herbivores are primary consumers in a food chain.
Q 5
Decomposers are not part of the food chain, so they are unimportant for ecosystems.
Q 6
A food web is made up of many interconnected food chains in the same ecosystem.
Q 7
Trophic level means the number of organisms in a population.
Q 8
Energy flow in an ecosystem is cyclic, returning to the sun.
Q 9
Only about 10% of energy is transferred from one trophic level to the next higher level.
Q 10
Because of energy loss, food chains are usually limited to four or five trophic levels.
Q 11
Biodegradable wastes are easily broken down by microorganisms.
Q 12
Plastics and metals are good examples of biodegradable wastes.
Q 13
Non-biodegradable waste always remains harmless in the environment.
Q 14
Biological magnification means gradual increase in concentration of persistent pollutants along a food chain.
Q 15
In biomagnification, organisms at the producer level show the highest concentration of toxic chemicals.
Q 16
Ozone in the upper atmosphere protects life on Earth from harmful ultraviolet radiation.
Q 17
Chlorofluorocarbons (CFCs) released from old refrigerators and aerosols contribute to ozone layer depletion.
Q 18
Ozone is completely harmless at ground level.
Q 19
Managing garbage we produce mainly means mixing all waste and dumping it in open areas.
Q 20
The three R’s—Reduce, Reuse and Recycle—help in decreasing the amount of solid waste.
Q 21
Composting is a useful method for managing biodegradable household waste.
Q 22
Waste segregation at source makes recycling and treatment of garbage easier.
Q 23
All human activities only improve the environment and never harm it.
Q 24
Forests and ponds are examples of natural ecosystems, whereas crop fields and aquariums are artificial ecosystems.
Q 25
Decomposers act only on producers and never on consumers.
Key Takeaways — Our Environment
Core facts for CBSE Boards & exams
1
Ecosystem = biotic (living) + abiotic (non-living) components interacting together.
2
Food chain: Producer → Primary Consumer → Secondary Consumer → Tertiary Consumer.
3
10% Law (Lindemann): only 10% of energy transfers to the next trophic level.
4
Biodegradable waste: decomposed by microbes (paper, food); Non-biodegradable: does not decompose (plastic, DDT).
5
Ozone (O₃) layer absorbs harmful UV-B and UV-C radiation; CFCs deplete the ozone layer.
6
Biological magnification: concentration of non-biodegradable chemicals INCREASES up the food chain.