Our Environment — Class 10 Biology NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 10 Biology chapter "Our Environment" — 7 important questions with detailed answers for CBSE board exam preparation.
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TL;DR: Free step-by-step NCERT solutions for Class 10 Biology chapter "Our Environment" — 7 important questions with detailed answers for CBSE board exam pre…
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Key Questions Covered:
- Define ecosystem. Describe the biotic and abiotic components of an ecosystem.
- What is a food chain? Explain with examples and describe the 10% rule (10% en…
- What is a food web? How does it differ from a food chain?
- What is pollution? Distinguish between biodegradable and non-biodegradable su…
- What is the ozone layer? Why is ozone depletion a concern? What are ozone-dep…
- What is bioaccumulation and biomagnification? How do they occur and why are t…
- + 1 more questions in the full chapter
Solutions Summary:
| Question | Status |
|---|---|
| Define ecosystem. Describe the biotic and abiotic compone… | ✓ Solved |
| What is a food chain? Explain with examples and describe … | ✓ Solved |
| What is a food web? How does it differ from a food chain? | ✓ Solved |
| What is pollution? Distinguish between biodegradable and … | ✓ Solved |
| What is the ozone layer? Why is ozone depletion a concern… | ✓ Solved |
| What is bioaccumulation and biomagnification? How do they… | ✓ Solved |
Showing 6 of 7 questions
Q1: Define ecosystem. Describe the biotic and abiotic components of an ecosystem.
Ecosystem is a functional unit consisting of all living organisms and their physical environment interacting together. It is self-sustaining and capable of recycling nutrients.
Biotic components (living):
1. Producers (Autotrophs):
- Green plants that manufacture their own food through photosynthesis
- Form the base of food chain and food web
- Example: grasses, trees, algae
2. Consumers (Heterotrophs):
a) Primary consumers (Herbivores) - eat producers
Example: grasshoppers,...
Q2: What is a food chain? Explain with examples and describe the 10% rule (10% energy law).
Food chain:
- A linear sequence showing energy flow from one organism to another
- Each organism eats the one before and is eaten by the one after
- Starts with producer (plant) and ends with top carnivore
- Simple representation of who eats whom
Example food chain in a forest:
Grass → Grasshopper → Bird → Hawk
(Producer) → (Primary consumer) → (Secondary consumer) → (Tertiary consumer)
Another example in aquatic ecosystem:
Alga → Small fish → Large fish → Eagle
Trophic levels:
- Trophic leve...
Q3: What is a food web? How does it differ from a food chain?
Food web:
- A complex network of interconnected food chains
- Shows multiple feeding relationships in an ecosystem
- Many organisms can eat multiple food sources
- Realistic representation of feeding relationships
- Shows that energy flow in ecosystems is not linear but branching
Example food web in a forest:
- Grass is eaten by grasshopper, rabbit, and deer
- Grasshopper is eaten by bird and lizard
- Rabbit is eaten by hawk and fox
- Bird is eaten by hawk
- Lizard is eaten by snake
- Snake is ...
Q4: What is pollution? Distinguish between biodegradable and non-biodegradable substances.
Pollution:
- The introduction of harmful substances into the environment
- Causes adverse effects on living organisms and physical environment
- Can be in air, water, or soil
- Sources: factories, vehicles, agriculture, households, plastic waste
- Types: air pollution, water pollution, soil pollution, noise pollution, light pollution, thermal pollution
Biodegradable substances:
- Can be broken down by natural decomposers (bacteria, fungi)
- Decompose through chemical and biological processes
- ...
Q5: What is the ozone layer? Why is ozone depletion a concern? What are ozone-depleting substances?
Ozone layer:
- Layer of ozone (O3) gas in Earth's stratosphere
- Located 10-50 km above Earth's surface
- Formed when UV radiation splits O2 molecules
- Protects life on Earth from harmful ultraviolet (UV) radiation
Functions of ozone layer:
1. Absorbs UV-B and UV-C radiation from Sun
2. Prevents harmful radiation from reaching Earth's surface
3. Makes life on land possible
4. Prevents skin cancer, cataracts, and immune system damage
5. Protects phytoplankton in oceans
Ozone depletion:
- Reduc...
Q6: What is bioaccumulation and biomagnification? How do they occur and why are they dangerous?
Bioaccumulation:
- Accumulation of non-biodegradable substances in the body of an organism
- Substance enters organism through various routes (ingestion, absorption)
- Cannot be broken down or excreted efficiently
- Concentration increases over time
- Happens within a single organism
Example of bioaccumulation:
- DDT pesticide sprayed on crops
- Enters plant tissues
- Animals eating plants consume DDT
- DDT accumulates in animal tissues over years
- Concentration in animal becomes much higher t...
Showing 6 of 7 questions. Visit the full page for complete solutions.