RBSE Class 12 Biology Notes Chapter 15 Biodiversity and Conservation

These comprehensive RBSE Class 12 Biology Notes Chapter 15 Biodiversity and Conservation will give a brief overview of all the concepts.

RBSE Class 12 Biology Chapter 15 Notes Biodiversity and Conservation

→ If you look around yourself you observes enormous diversity of life. There are more than 20,000 species of ants, 3,00,000 species of beetles, 28,000 species of fishes and nearly 20,000 species of orchids on earth since life orginated nearly 3.8 billion years ago. Hence, bio diversity refers to the sum total of all life forms that exists at all levels of biological organisation. Biodiversity can be of genetic, species 
and ecological type. We should focus on conservation efforts to protect diversity at all these levels.

→ More than 1.5 million species have been reported on earth but there might still be nearly 6 million species on earth waiting to be discovered and named. Out of these 770 percent are animals, out of these 70% are insects.

→ The group fungi has more species than all the vertebrates species combined. India with about 45,000 species of plants and twice as many species of animals, is one of the 12 mega diversity countries of the world.

→ There is no particular trend in species diversity on the earth. In general species diversity is higher in tropical areas and decreases towards poles. The main reason for this trend are that the tropics has more evolutionary time, tropic has the relatively constant environment throught the history. It is believed that communities with high diversity tend to be less variable, more productive and more resistant to biological inversions.

→ Now a day there is an great threat for biological diversity loss and mass extinction. The causes of high extinction rates at present include habitat (in particular forests) loss and fragmentation, over exploitation, biological invasions and co-extenctions. Earth’s rich biodiversity is vital for the very survival of mankind. The main reasons for conserving biodiversity are narrowly utilitatrian, broadly utilitarian and ethical. Biodiversity conservation may be In situ and Ex situ. In In situ conservation is done in their natural habitats like biosphere reserves, national parks etc. Ex situ conservation involves outside habitat techniques like gene banks etc., protective maintenance like in zoological parks, Botanical gardens, tissue culture etc.

→ In IUCN maintain a document called red list or red data book of taxa that are facing the risk of extinction.

→ Biodiversity: Occurence of different types of species, genes, genetic pool, habitat and ecosystem at a given area at a given time.

→ Biodiversity Loss: Mainly due to four reasons habitat loss and fragmentation, overexploitation, Alien (exotic) species invasion and coextinctions.

→ Alien (Exotic) Species: Any species which is not found in the study area, may be unintentionally on deliberately introduced into the exotic habitat. 

→ In Situ Conservation: Protection of any species in their natural habitat. It is done in biosphere reserves, national parks, wildlife sanctuaries and in sacred groves.

→ Ex Situ Conservation: Threatened animals and plants are taken out from their national habitats and placed in special care units for their protection and reproduction. Example, zoological parks, botanical gardens, Tissue culture, seed hanks and gene banks.

→ Cryopreservation: This technique involves the preservation of eggs, spermns, embroys, etc., at minus -196°C temperature in riable and fertile conditions.

→ IUCN: International union for conservation of nature an global agency to protect nature.

→ Red List/Red Data Book: A document maintained by IUCN having the record of endangered, thratened, vulnerable,' least concern categories of species in order of their importance in conservation.