Chapter 3 of 11
Revision Notes
Biodiversity — Revision Notes
ICSE · Class 9 · Environmental Science
Biodiversity revision notes for ICSE Class 9 Environmental Science: 4 topics in quick points. Part of the ICSE Class 9 Environmental Science syllabus.
57 questions40 flashcards5 concepts
Interactive on Super Tutor
Studying Biodiversity? Get the full interactive chapter.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for revision notes and more.
Free trial, no card needed.
Key Topics to Revise
1
1. Meaning and Types of Biodiversity
- Biodiversity includes genetic differences within species, diversity of species, and variety of ecosystems.
- The term biodiversity is derived from biological diversity.
- There are three main types of biodiversity: genetic diversity, species diversity, and ecosystem diversity.
2
2. Genetic Diversity and Conservation
- Genetic diversity arises due to mutations, gene flow, genetic drift, and sexual reproduction.
- Traditional rice varieties show better resistance to floods or pests than genetically uniform, high-yield varieties.
- High genetic diversity helps populations adapt and survive environmental changes.
3
3. Species Diversity and Its Measurement
- Species diversity means the variety, number, and relative abundance of species in an ecosystem.
- Species richness is the total number of different species in an area.
- Species evenness is the distribution of individuals among different species.
4
4. Indicator Species, Keystone Species, and Ecosystem Health
- Indicator species act as early warning signs of environmental changes.
- Frogs indicate water quality and lichens indicate air quality.
- Removal of indicator species may show environmental problems but may not immediately disturb the ecosystem.
Get complete notes with diagrams and examples
Full NotesKey Concepts
Biodiversity refers to the total varietyGenetic diversity is the variationSpecies diversity is the varietyEcosystem diversity is the varietyIndicator species reflect ecosystem health
Frequently Asked Questions
What are the important topics in Biodiversity for ICSE Class 9 Environmental Science?
Key topics in Biodiversity include Meaning and Types of Biodiversity, Genetic Diversity and Conservation, Species Diversity and Its Measurement, Indicator Species, Keystone Species, and Ecosystem Health. Study these first, then practise questions on each for Class 9 exams.
How should I revise Biodiversity for Class 9 exams?
Learn the core ideas first, then work through the 57 practice questions on Biodiversity. Revise 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.
More resources for Biodiversity
For serious students
Get the full Biodiversity chapter — start free.
Quizzes, flashcards, an AI doubt solver and a study plan for ICSE Class 9 Environmental Science. Free to start, no card needed.