Our Environment Class 10 Notes in Hindi + English | Complete Chapter Explanation, Important Questions & Summary

Our Environment Class 10 Notes: “हमारा पर्यावरण (Our Environment)” कक्षा 10 विज्ञान का एक बेहद महत्वपूर्ण अध्याय है, जो बोर्ड परीक्षा के दृष्टिकोण से भी काफी अहम माना जाता है। इस अध्याय में हम पारिस्थितिकी तंत्र (Ecosystem), खाद्य श्रृंखला (Food Chain), खाद्य जाल (Food Web), पोषण स्तर (Trophic Levels), जैव अपघटनीय और अजैव अपघटनीय पदार्थ, तथा जैव आवर्धन (Biological Magnification) जैसे महत्वपूर्ण टॉपिक्स को सरल भाषा में समझते हैं।

आज के समय में पर्यावरण संरक्षण (Environment Protection) की आवश्यकता पहले से कहीं अधिक बढ़ गई है, इसलिए इस अध्याय की जानकारी न केवल परीक्षा के लिए बल्कि जीवन के लिए भी जरूरी है। इस पोस्ट में आपको “Our Environment Class 10 Notes” हिंदी और अंग्रेज़ी दोनों माध्यम में आसान उदाहरणों के साथ मिलेंगे, जिससे आपकी तैयारी मजबूत होगी और आप परीक्षा में अच्छे अंक प्राप्त कर पाएंगे। For Objective Questions, Visit Learneasily8.

Our Environment Class 10 Notes: Complete Details

English:
Environment includes all the living (biotic) and non-living (abiotic) components around us that affect life.

Hindi:
पर्यावरण वह सब कुछ है जो हमारे चारों ओर मौजूद है—जीवित (जैविक) और निर्जीव (अजैविक) तत्व, जो जीवन को प्रभावित करते हैं।

Examples: Air (वायु), Water (जल), Plants (पौधे), Animals (जानवर)

Ecosystem (पारिस्थितिकी तंत्र)

English:
An ecosystem is a system where living organisms interact with each other and with their environment.

Hindi:
पारिस्थितिकी तंत्र वह प्रणाली है जिसमें जीवित जीव आपस में और अपने पर्यावरण के साथ अंतःक्रिया करते हैं।

Examples: Forest, Pond, Grassland (जंगल, तालाब, घासभूमि)

Components of Ecosystem (पारिस्थितिकी तंत्र के घटक)

(A) Biotic Components (जैविक घटक)

1. Producers (उत्पादक)
   • Plants (पौधे)
   • Make food using sunlight (Photosynthesis)
   • Example: Grass, Trees
2. Consumers (उपभोक्ता)
   • Depend on others for food
   • Types:
     • Primary consumers (शाकाहारी) – Goat, Deer
     • Secondary consumers (मांसाहारी) – Frog
     • Tertiary consumers – Lion, Tiger
3. Decomposers (अपघटक)
   • Break down dead organisms
   • Example: Bacteria, Fungi
   • Help in recycling nutrients

(B) Abiotic Components (अजैविक घटक)

• Air (वायु), Water (जल), Soil (मिट्टी), Temperature (तापमान)

Read More: Class 10 Life Processes Case Study Questions | जीवन प्रक्रियाएँ केस स्टडी प्रश्न (CBSE Board Pattern)

Food Chain (खाद्य श्रृंखला)

English:
A food chain shows how energy flows from one organism to another.

Hindi:
खाद्य श्रृंखला बताती है कि ऊर्जा एक जीव से दूसरे जीव तक कैसे पहुँचती है।

Example:
Grass → Deer → Lion
घास → हिरण → शेर

Food Web (खाद्य जाल)

English:
A network of interconnected food chains.

Hindi:
कई खाद्य श्रृंखलाओं का आपस में जुड़ा हुआ जाल खाद्य जाल कहलाता है।

More stable than a single food chain.

Trophic Levels (पोषण स्तर)

• Each step in food chain is called trophic level

Level	English	Hindi Example
1	Producers	Plants (पौधे)
2	Primary consumers	Goat (बकरी)
3	Secondary consumers	Snake (साँप)
4	Tertiary consumers	Eagle (गरुड़)

10% Law (ऊर्जा का नियम)

English:
Only 10% of energy is transferred from one trophic level to the next.

Hindi:
हर पोषण स्तर से अगले स्तर तक केवल 10% ऊर्जा ही पहुँचती है।

👉 Example:
1000 J → 100 J → 10 J → 1 J

Read Also: Periodic Classification of Elements Class 10 Notes | Trends, MCQs, Case Study Questions (Hindi + English)

Environmental Problems (पर्यावरणीय समस्याएँ)

1. Pollution (प्रदूषण)

• Air pollution (वायु प्रदूषण)
• Water pollution (जल प्रदूषण)
• Soil pollution (मिट्टी प्रदूषण)

👉 Causes: Vehicles, factories, plastic

2. Non-biodegradable Waste (अविघटनीय कचरा)

• Plastic, glass, metals
• Do not decompose easily

👉 Harm environment for long time

9. Biodegradable and Non-biodegradable Substances

Type	English	Hindi
Biodegradable	Decompose naturally	जैव अपघटनीय
Non-biodegradable	Do not decompose	अजैव अपघटनीय

👉 Examples:

• Biodegradable: Food waste
• Non-biodegradable: Plastic

Biological Magnification (जैव आवर्धन)

English:
Increase in concentration of harmful substances at higher trophic levels.

Hindi:
खाद्य श्रृंखला के उच्च स्तरों पर विषैले पदार्थों की मात्रा बढ़ना जैव आवर्धन कहलाता है।

👉 Example:
Pesticides → Fish → Humans

Waste Management (कचरा प्रबंधन)

3R Rule:

• Reduce (कम करें)
• Reuse (दोबारा उपयोग करें)
• Recycle (पुनर्चक्रण करें)

👉 Example: Use cloth bags instead of plastic

Ozone Layer (ओजोन परत)

• Protects from harmful UV rays
• Damage caused by CFC gases

👉 Leads to global warming & health issues

Importance of Environment (पर्यावरण का महत्व)

• Provides oxygen (ऑक्सीजन देता है)
• Maintains balance (संतुलन बनाए रखता है)
• Supports life (जीवन को सहारा देता है)

Exam Important Points (बहुत महत्वपूर्ण बिंदु)

✔ Food chain always starts with producers
✔ Energy decreases at each trophic level
✔ Decomposers recycle nutrients
✔ Plastic is harmful (non-biodegradable)
✔ 10% law is very important for numericals

Short Revision (Quick Recap)

• Environment = Biotic + Abiotic
• Ecosystem = Interaction of living + non-living
• Food Chain → Energy flow
• Food Web → Network
• 10% Law → Energy loss
• Biodegradable vs Non-biodegradable
• Biological Magnification → Toxic increase

Know More: Carbon and Its Compounds – Complete Notes (Class 10)

Assertion–Reason Questions (Our Environment – Class 10)

👉 Directions (निर्देश):
For each question, choose the correct option:
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true

Q1. Assertion (A): Food chains are generally short.
Reason (R): Energy transfer between trophic levels is inefficient.

Answer: (a)
👉 Explanation: Only 10% energy is transferred, so chain remains short.

Q2. Assertion (A): Decomposers are essential for the environment.
Reason (R): They recycle nutrients back into the ecosystem.

Answer: (a)

Q3. Assertion (A): Biological magnification increases at higher trophic levels.
Reason (R): Non-biodegradable substances accumulate in organisms.

Answer: (a)

Q4. Assertion (A): Producers form the first trophic level.
Reason (R): They make food using sunlight.

Answer: (a)

Q5. Assertion (A): Food web is more stable than food chain.
Reason (R): It provides multiple feeding options.

Answer: (a)

Q6. Assertion (A): Plastic is biodegradable.
Reason (R): It decomposes naturally by microorganisms.

Answer: (d)
👉 Explanation: Plastic is non-biodegradable.

Q7. Assertion (A): Ozone layer protects Earth from UV rays.
Reason (R): It absorbs harmful ultraviolet radiation.

Answer: (a)

Q8. Assertion (A): All organisms in an ecosystem are interdependent.
Reason (R): They are connected through food chains.

Answer: (a)

Q9. Assertion (A): Energy flow in ecosystem is cyclic.
Reason (R): Energy is lost as heat at each level.

Answer: (c)
👉 Explanation: Energy flow is unidirectional, not cyclic.

Q10. Assertion (A): Biodegradable waste causes long-term pollution.
Reason (R): It breaks down easily.

Answer: (d)

Q11. Assertion (A): Trophic levels show feeding positions in a food chain.
Reason (R): Each level has organisms with same food habits.

Answer: (a)

Q12. Assertion (A): Use of pesticides can harm humans.
Reason (R): They enter food chain and accumulate.

Answer: (a)

Q13. Assertion (A): More the trophic level, less the available energy.
Reason (R): Energy is lost at each level.

Answer: (a)

Q14. Assertion (A): Green plants are called autotrophs.
Reason (R): They cannot make their own food.

Answer: (c)

Q15. Assertion (A): Non-biodegradable substances remain in environment for long.
Reason (R): They cannot be broken down by microorganisms.

Answer: (a)

Case Study Questions – Our Environment (Class 10)

Case Study 1: Forest Ecosystem (वन पारिस्थितिकी तंत्र)

Passage:
A forest ecosystem consists of producers like trees and plants, herbivores like deer, and carnivores like tigers. Decomposers such as bacteria and fungi break down dead organisms and recycle nutrients back into the soil.

प्रश्न:

1. Which organism is a producer?
   (a) Tiger
   (b) Deer
   (c) Tree
   (d) Bacteria
   Answer: (c)
2. What is the role of decomposers?
   (a) Produce food
   (b) Eat plants
   (c) Break down dead matter
   (d) Hunt animals
   Answer: (c)
3. Which is a primary consumer?
   (a) Tiger
   (b) Deer
   (c) Bacteria
   (d) Tree
   Answer: (b)
4. What will happen if decomposers are removed?
   Answer: Nutrient recycling will stop, and dead matter will accumulate.

Case Study 2: Aquatic Ecosystem (जल पारिस्थितिकी तंत्र)

Passage:
In a pond ecosystem, algae produce food using sunlight. Small fish eat algae, and bigger fish eat smaller fish. Harmful chemicals from industries enter water and affect aquatic life.

प्रश्न:

1. Who is the producer in this ecosystem?
   Answer: Algae (शैवाल)
2. What type of consumer is small fish?
   Answer: Primary consumer
3. What is the effect of harmful chemicals?
   Answer: Water pollution and death of aquatic organisms
4. Name the process where harmful substances increase in food chain.
   Answer: Biological magnification (जैव आवर्धन)

Case Study 3: Food Chain & Energy Flow

Passage:
In a food chain, energy flows from plants to herbivores and then to carnivores. Only 10% of energy is transferred to the next trophic level, while the rest is lost as heat.

प्रश्न:

1. Why is food chain short?
   Answer: Due to loss of energy at each level
2. What percentage of energy is transferred?
   Answer: 10%
3. What is the first trophic level?
   Answer: Producers
4. Is energy flow cyclic?
   Answer: No, it is unidirectional

Case Study 4: Pollution (प्रदूषण)

Passage:
Plastic waste and industrial chemicals are non-biodegradable and remain in the environment for a long time. These substances can enter the food chain and harm living organisms.

प्रश्न:

1. Why is plastic harmful?
   Answer: It is non-biodegradable
2. What happens when chemicals enter food chain?
   Answer: Biological magnification occurs
3. Suggest one solution to reduce pollution.
   Answer: Use of biodegradable materials / follow 3R (Reduce, Reuse, Recycle)
4. Give one example of non-biodegradable waste.
   Answer: Plastic

Case Study 5: Ozone Layer (ओजोन परत)

Passage:
The ozone layer protects Earth from harmful ultraviolet rays. Use of CFC gases damages the ozone layer, leading to environmental and health issues.

प्रश्न:

1. What is the function of ozone layer?
   Answer: Protects from UV rays
2. Which gas damages ozone layer?
   Answer: CFC (Chlorofluorocarbon)
3. What can happen due to ozone depletion?
   Answer: Skin diseases, global warming
4. Suggest one preventive measure.
   Answer: Avoid use of CFC products