Ecosystem is a basic concept in biology that explains the interaction between living organisms and their environment. The term was introduced by Arthur Tansley.
This unit covers key topics like biotic and abiotic components, energy flow, ecological succession, and biogeochemical cycles. It is an important chapter for exams and helps students understand how nature maintains balance.
📥 Download Class 12 Biology Ecosystem Chapter Notes
Skip to PDF contentYou can easily download the complete Ecosystem Notes PDF for Class 12 Biology from the link below. These notes are specially prepared according to the Punjab Board syllabus and are perfect for exam preparation.
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❓ FAQs – Ecosystem (Class 12 Biology)
1. What is an ecosystem?
An ecosystem is a system where living organisms interact with each other and with their physical environment. The concept was introduced by Arthur Tansley.
2. What are the main components of an ecosystem?
The ecosystem has two main components:
- Biotic components (living organisms)
- Abiotic components (non-living factors like air, water, and temperature)
3. What is the difference between autecology and synecology?
Autecology studies a single organism or species and its environment, while synecology studies groups of organisms and their interactions within a community.
4. What is ecological succession?
Ecological succession is the gradual development of an ecosystem over time. It includes primary succession (starting from no life) and secondary succession (recovery of an existing ecosystem).
5. Why is the nitrogen cycle important?
The nitrogen cycle is important because it converts atmospheric nitrogen into usable forms for plants and animals, helping maintain ecosystem balance.
📝 MCQs – Ecosystem (Class 12 Biology Unit 25)
1. Who introduced the term “ecosystem”?
A) Charles Darwin
B) Arthur Tansley
C) Ernst Haeckel
D) Gregor Mendel
✔ Answer: B) Arthur Tansley
2. Which is an example of a biotic component?
A) Soil
B) Water
C) Plants
D) Sunlight
✔ Answer: C) Plants
3. Primary succession begins on:
A) Grasslands
B) Forests
C) Bare rocks
D) Lakes
✔ Answer: C) Bare rocks
4. Study of interactions of a single species with its environment is called:
A) Synecology
B) Autecology
C) Ecology
D) Genetics
✔ Answer: B) Autecology
5. Which cycle is responsible for converting atmospheric nitrogen into usable forms?
A) Carbon cycle
B) Water cycle
C) Nitrogen cycle
D) Oxygen cycle
✔ Answer: C) Nitrogen cycle