Class 12 Biology - RAJASTHAN
Biodiversity and Conservation
The chapter Biodiversity and Conservation in Class 12 Biology for Rajasthan Board (RBSE) explores the immense diversity of life on Earth at genetic, species, and ecological levels. Students will learn about patterns of biodiversity, latitudinal gradients, the alarming rate of species loss due to human activities, and the urgent need for conservation. The chapter covers crucial strategies like in-situ (national parks, biosphere reserves) and ex-situ (zoos, botanical gardens, gene banks) conservation. It holds high weightage in the RBSE board exams, frequently featuring direct theoretical questions, diagrams of biodiversity loss graphs, and important differentiation questions.
Start Learning FreeKey Concepts
Levels of Biodiversity
Biodiversity exists at three main levels: Genetic diversity (diversity within species), Species diversity (diversity among species in a given region), and Ecological diversity (diversity at the ecosystem level).
Latitudinal Gradients
Species diversity generally decreases as we move away from the equator towards the poles, making tropics rich in species due to undisturbed evolutionary time and solar energy.
The Evil Quartet
The four major causes of accelerated biodiversity loss are Habitat loss and fragmentation, Over-exploitation, Alien species invasions, and Co-extinctions.
In-situ Conservation
The conservation of endangered plants and animals in their natural habitats, such as National Parks, Wildlife Sanctuaries, and Biosphere Reserves.
Ex-situ Conservation
The conservation of threatened species outside their natural habitats through methods like Zoological parks, Botanical gardens, Cryopreservation, and Seed banks.
Important Formulas
Board Exam Info
In the Rajasthan Board (RBSE) Class 12 Biology exam, this chapter typically carries around 4 to 6 marks. Students can expect 1 objective/multiple-choice question, a short-answer question on the causes of biodiversity loss or conservation strategies, and occasionally a numerical or graphical question based on the Species-Area relationship.
Frequently Asked Questions
What is the difference between in-situ and ex-situ conservation?
In-situ conservation protects organisms within their natural habitat (e.g., National Parks), whereas ex-situ conservation protects them outside their natural habitat in artificial settings (e.g., Zoos and Botanical gardens).
What does the Z value signify in the Species-Area relationship?
The Z value represents the slope of the regression line. For most taxonomic groups, Z lies between 0.1 and 0.2, but for very large areas like continents, it ranges from 0.6 to 1.2.
Why is tropical biodiversity greater than temperate biodiversity?
Tropics have received more solar energy, remained relatively undisturbed for millions of years allowing more evolutionary time, and experience less seasonal variations, promoting higher species richness.
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