Class 12 Biology Chapter 13, Biodiversity and Conservation, highlights the variety of life forms found on Earth and explains why it is so important to conserve them. This chapter talks about different types of biodiversity, threats to biodiversity, reasons behind species extinction, and various conservation strategies. It also covers topics like national parks, biosphere reserves, and international efforts to protect endangered species. This chapter not only has theoretical importance but also builds environmental awareness among students.
I decided to write about this topic because biodiversity is not just a biology term—it is something we see and depend on in everyday life. From pollination by bees to forests that give us oxygen, every part of biodiversity supports our survival. But due to pollution, deforestation, and climate change, many species are now under threat. Understanding this chapter helps students realise how interconnected life forms are and why protecting even the smallest species matters. It also aligns well with questions asked in NEET and CBSE board exams. That’s why it’s important to download the PDF, revise regularly, and be aware of both textbook concepts and current environmental issues.
Main Topics Covered in Chapter 13 – Biodiversity and Conservation
Chapter 13 is a blend of scientific facts, real-world concerns, and examples from India and across the globe. Let’s break it down topic by topic.
What is Biodiversity?
Biodiversity refers to the variety of life forms on Earth, including animals, plants, fungi, and microorganisms. It is usually studied at three levels:
- Genetic Diversity: Variation within a species
- Species Diversity: Variety of species in a given area
- Ecosystem Diversity: Different types of ecosystems (e.g., forests, deserts, wetlands)
India is known as one of the 12 mega diversity countries in the world due to its rich flora and fauna.
Patterns of Biodiversity
Biodiversity is not spread equally across the planet.
- Latitudinal Gradient: Species diversity increases as we move from the poles to the equator
- Species-Area Relationship: Greater the area, more species it can support
This concept was first studied by German naturalist Alexander von Humboldt
Importance of Biodiversity
Biodiversity provides a range of benefits:
- Ecological balance: Helps maintain food chains
- Economic benefits: Source of medicine, food, timber
- Cultural value: Many plants and animals are part of our tradition
- Ecosystem services: Soil formation, climate regulation, water purification
Loss of Biodiversity
Four major causes of biodiversity loss (also known as The Evil Quartet):
- Habitat loss and fragmentation: Due to deforestation, urbanisation
- Over-exploitation: Excessive hunting, fishing, and cutting of trees
- Alien species invasion: Introduction of non-native species (e.g., Lantana in India)
- Co-extinction: When one species goes extinct, others dependent on it also vanish
Biodiversity Conservation
There are two main strategies to conserve biodiversity:
In-situ Conservation
Protecting species in their natural habitat
- Examples: National parks, wildlife sanctuaries, biosphere reserves
- Notable Indian sites: Kaziranga, Jim Corbett, Sunderbans, Nilgiri
Ex-situ Conservation
Conserving species outside their natural habitat
- Examples: Zoological parks, botanical gardens, seed banks, gene banks
- Important institutions: National Bureau of Plant Genetic Resources (NBPGR)
Hotspots and Red Data Book
- Biodiversity Hotspots: Areas with high species richness and endemism but under threat
India has 4 hotspots – Himalayas, Indo-Burma, Western Ghats-Sri Lanka, and Sundaland - IUCN Red Data Book: Lists endangered and threatened species globally
Examples: Indian vulture, Asiatic lion, Snow leopard
Sacred Groves
Traditional conservation method where communities protect forests due to religious beliefs
- Found in states like Meghalaya, Rajasthan, Madhya Pradesh
Download PDF – NCERT Class 12 Biology Chapter 13
If you want to study this chapter in detail or revise it before your exams, downloading the official NCERT PDF is a great option. It contains all diagrams, explanations, and NCERT-based questions.
