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Chapter 2 of 11
Revision Notes

Natural Processes and Biogeochemical Cycles

ICSE · Class 9 · Environmental Science

Quick revision notes for Natural Processes and Biogeochemical Cycles — ICSE Class 9 Environmental Science. Key concepts, formulas, and definitions for last-minute revision.

65 questions52 flashcards5 concepts

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Key Topics to Revise

1

1. Biological Processes Supporting Life

  • Photosynthesis produces food and oxygen.
  • Decomposition recycles nutrients back into the environment.
  • Adaptation helps organisms survive in different habitats.
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2. Photosynthesis

  • Photosynthesis takes place in chloroplasts which contain chlorophyll, a green pigment that absorbs sunlight.
  • During photosynthesis, water molecules split into hydrogen and oxygen through photolysis.
  • Oxygen released during photosynthesis exits through the stomata.
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3. Factors Affecting Photosynthesis

  • Light intensity affects the rate of photosynthesis.
  • Carbon dioxide concentration affects the rate of photosynthesis.
  • Water availability is essential for photosynthesis.
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4. Decomposition

  • Decomposition breaks dead organic matter into simpler inorganic substances.
  • Microorganisms such as bacteria and fungi carry out decomposition.
  • The stages of decomposition are fragmentation, leaching, catabolism, humification, and mineralisation.

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Full Notes

Key Concepts

Photosynthesis is the biological process byDecomposition is the biological process byAdaptation is the gradual evolutionary processCamel adaptations include a humpEvolution is the gradual genetic change

Frequently Asked Questions

What are the important topics in Natural Processes and Biogeochemical Cycles for ICSE Class 9 Environmental Science?
Natural Processes and Biogeochemical Cycles covers several key topics that are frequently asked in ICSE Class 9 board exams. Focus on the core concepts listed on this page and practise related questions to build confidence.
How to score full marks in Natural Processes and Biogeochemical Cycles — ICSE Class 9 Environmental Science?
Understand the core concepts first, then work through the 65 practice questions available for this chapter. Revise formulas and definitions regularly, and use flashcards for quick recall before the exam.

Sources & Official References

Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.

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