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Westerm Ghats and Sri lanka; Indo-Burma; Himalaya called biodiversity hot spots as they show 

(i) High level of species richness 

(ii) High degree of endemism

Although all the biodiversity hot spots put together cover less than 2 percent of the earth’s land area, the number of species they collectively harbour is extremely high and strict protection of these hot spots could reduce the ongoing mass extinctions by almost 30 per cent.

Hot spots are the richest & most threatened reservoirs of plant & animal life on earth. Hot spots concept was developed by N.Meyers to designate priority area in situ conservation. The two criteria used for determining a hot spot – 1. Number of endemic species.2. Degree of threat measured in terms of habitat loss. Two hot spots – Western ghats, Eastern Himalayas.

Biodiversity hot spot: regions with very high levels of species richness and high degree of endemism.(species confined to that region and not found anywhere else)

Hot spot in biodiversity is also regions of accelerated habitat loss. 

Factors for declaring a hot spot

• No. of Endemic Species i.e. the species which are found no where else 
• Degree of threat, which is measured in terms of Habitat loss 

Eastern Himalaya and Western Ghat.

The species which gets totally eliminated from the earth is called extinct species.

Some species are harmful to human

eg: HIV, Small pox vires etc.

Such species are not part of any food chains or webs. So, their extinction will not effect ecosystem. And also their extinction can be beneficial to humans.

eg:- HIV, small pox vires, plasmodium species etc.

Dark bucks > Bee eaters, Harriers

In Siberia the Siberian cranes migrate into Rajasthan.

The odorous substance obtained from the flowers of Khejri is Patuletin.

Hot spot of India is western Ghat.

The botanical name of Khejri is Prospis cineraria.

Prosopis is called as “Kalp Taru” of Rajasthan.

Rajasthan State bird, State tree & State flower are Godawan, Khejri, Rohida.

Rajasthan State bird is Godawan.

1. Siberian crane

(a) Red Data List given by IUCN includes endangered plant and animal species. It is the world’s most comprehensive inventory of the global conservation status of biological species. The red data list was first published in the first edition of “Red Data Book” in 1963.

(b) A species of animal or plant that is seriously at risk of extinction.

(c) Royal tiger (Panther tigies) was declared as National animal in 1972-73. For the conservation of Royal tiger, project tiger was started on April 1,1973 with the help of WWF (World Wildlife Fund).

Initially 9 project tigers were established which is now increased to 47 upto 2014. Out of them three project tiger are situated in “Rajasthan viz.-

(a) Ranthambore NP project tiger.
(b) Sariska NP project tiger.
(c) Mukendra hills project tiger. ,
(d) Loss and fragmentation of natural habitats, introduction of exotic species, over exploitation, pollution of soil, water and air, deforestation, agricultural extension are main reason threatening biodiversity.

It plays vital role in preserving the ecosystem of arid and semi-arid areas. It is a symbol of socio-economic development. All the parts of this tree are useful. Hence, it is called as “Kalptaru”.

Godawan or Great Indian Bustard (Choriotiss nigriceps) is declared as Rajasthan state bird (1981). It is a critically endangered species and the number of godawas was 1500 in 1981, 250 in 2011. 40 in 2014 and only 13 in June, 2015. It is a large bird with long bare legs. It’s height is about one metre. The body is brownish with black patch spotted. It is omnivorous and it feeds on grass seeds, insects, berries, rodents, reptiles etc. Adult weight is 6 to 18 kg.

Birds : Stork, Spoonbill, Vulture, Eagle, Siberian crane, Saras (Gruidae), Warbler (Phylloscopus), Pipit (Anthus), Sandpiper (Scolopacidae), Flower bird etc.

Aquatic animals : Turtle, Frog, Leech, Snail, Water snake, Tomcat other etc.

'Alien species' invasions are those that are, firstly, outside their natural distribution area, and, secondly, threaten biological diversity.

Plants : Lantana camara 

Animals : Equs caballus, Canis familiaris (dog).

• Biodiversity is important for productivity, stability, resilience and health of ecosystems.
• Biodiversity is important not only for ecosystem function but also for very survival of human race on earth.

The world’s largest tropical rainforest of Amazon, there are around 40,000 plant species, nearly 1,300 bird species, 3,000 types of fish, 427 species of mammals and more than 1,25,000 invertebrates

The three components or levels of biodiversity are

• Genetic diversity
• Species diversity
• Ecological diversity

Ecological diversity has again 3 components – alpha diversity (with in community diversity), beta diversity (between community diversity) and gamma diversity (regional diversity).

Unlike temperate regions subjected to frequent glaciations in the past, tropical latitudes have remained relatively undisturbed for millions of years and thus, had a long evolutionary time for species diversification.

Tropical environments. Unlike temperate ones, are less seasonal, relatively more constant and predictable, promotes niche specialization and lead to greater species diversity. 

There is more solar energy available in the tropics, which contribute to higher productivity.

IUCN (2004) has described slightly more than 1.5 million species of plants and animals. 

According to Robert May estimates the global species diversity is about 7 million.

In tropics:-

No Catastrophes – In tropics, there has been no catastrophes but is temperate areas glaciations and other catastrophes have caused large scale of destruction.

Non-seasonal Environment –

In tropics, seasons are nearly uniform. It promotes rich and increases species diversity.

Solar Energy – 

Tropics get lots of sunlight which enhances productivity.

The variety of species within a given region is called the species diversity.

(David Tilman)

(A) Insects Habitat, Mostly terrestrial

(B) Fishes Habitat, Aquatic.

David Tilman’s long-term ecosystem experiments using outdoor plots provide some tentative answers. Tilman found that plots with more species showed less year-to-year variation in total biomass. He also showed that in his experiments, increased diversity contributed to higher productivity. Although, we may not understand completely how species richness contributes to the well-being of an ecosystem, we know enough to realise that rich biodiversity is not only essential for ecosystem health but imperative for the very survival of the human race on this planet.

The term genetic diversity refers to the diversity of genes within a species.

It is important because

• Greater the genetic diversity among the organisms of a species, more sustenance, has against environmental perturbations.
• Genetically uniform populations are highly prone to diseases and harsh environment.

1. Humans have exploited natural resources beyond their needs. 

2. The excessive consumption and accumulation have resulted into problem of over¬exploitation. 

3. Overexploitation of resources has caused threats to various organisms. 

4. Dodo bird, stellar sea cow and passenger pigeon are extinct due to overexploitation. 

5. Over exploitation of fish from sea has also resulted into dearth of fish.

• Rauwolfia vomitoria is the plant that yields reserpine.
• The genetic variation is shown in terms of the potency and concentration of the active chemical reserpine.

(a) Fishes

(b) Amphibians.

Steller’s sea cow and passenger pigeon

Correct option is (a) Recycling and recovery

Correct option is (b) a particular pollutant

Correct option is (c) 100 dB

Parthenium / Carrot grass.

The desert plants are adapted to survive in water deficient conditions. They possess adaptations to conserve water such as thick cuticle, reduced leaf and low rate oi transpiration. 

The mangrove plant, on the other hand, are adapted to survive in water logged and anoxic conditions. They possess prominent leaves the high rate of transpiration. Thus, the desert plants have different adaptations than mangrove plants to survive and cannot be found in a mangrove.

Plants that inhabit rain forest are well adapted to that particular habitat. The climate of rain-forest is wet and humid and in this climate, large trees and shrubs are predominantly present. 

The climate of wetlands, on the other hand, is cool and wet.

(i) It is an example of ex-situ conservation (off-site conservation) In this approach, threatened plants and animals are taken out of their natural habitat and placed into suitable settings and given special 

(ii) Cryopreservation and tissue culture are two ways that help in ex-situ conservation. 

In cryopreservation, gametes of threatened species are preserved in viable and fertile conditions at subzero temperatures, which helps in preserving these cells for longer periods. 

In tissue culture, plants are propagated from a small mass of tissue called callus.

As a biology student,I would suggest the following method that can protect these threatened species from becoming extinct. 

Ex situ conservation : The threatened species of plants and animals are taken out of their habitats and are kept in special setting such as zoological parts, botanical gardens and wildlife sanctuaries. In the present scenario, the gametes of endangered species can be preserved by methods like cryopreservation and can be fertilised in vitro followed by propagation through tissue culture methods. Similarly, seeds can be preserved in seed banks. This type of conservation method is an off-site conservation method.

Genetic level : A single species might show high diversity at genetic level, 

e.g. Rauwolfia vomitoria/Mango

Specific level : Diversity at species level, 

e.g. Amphibian species 

Ecological level : Diversity at ecosystem level, 

e.g. Estuaries/Deserts/rain forest/mangroves/Coral reef/ wet lands/estuaries/ alpine meadows

National parks are the biosphere reserves maintained by the government for the betterment & protection of wild life where grazing, cultivation & forestry is not allowed. While sanctuaries are the tracts of land where animals can take refuge & they are protected. In sanctuaries the activities like tilling of land harvesting of timber collection of forest product etc. are allowed. 

• (a) (i)  Narrowly utilitarian - related examples like derive economic benefits from nature food (cereals, pulses, fruits) / firewood / fibre / construction materials / industrial products (tannins, Iubricants, dice, resins, perfumes) / product of medicinal importance / drugs.
• Broadly utilitarian - 20% of total O₂ from Amazon forests / pollination / aesthetic pleasures. 
• Ethical - millions of species (plants, animals, microbes) share this planet / we need to realise that every species has an intrinsic value (even if it may not current or any economic value to us) / we have a moral duty to care for their well being and pass on our biological legacy to future generations.
• (ii) In situ conservation / biosphere reserves/ national parks / sanctuaries / sacred groves.
• Ex situ conservation / zoological parks / botanical gardens i wild life safari parks / cryopreservation / seed banks / tissue culture (eggs in vitro) 

(b) Hot spots : regions with high level of species richness, high degree of endemism. 

Sacred groves : tracts of forest containing tree / wild life were venerated and given total protection // to protect last refuses for a large number of rare, and threatened plants.

Detailed Answer:

(a) We should conserve bio-diversity because of the following reasons : 

(i) Humans derive countless economic benefits from nature like 

(1) Food (cereals, pulses, fruits) 

(2) Wood, fibre, construction material, industrial products (tannins, lubricants, dyes, resins, perfumes) and 

(3) Products of medicinal importance.

(ii) Biodiversity plays a major role in many ecosystem services that nature provides. Such as production of oxygen and pollination. 

(iii) It is our moral duty to care for well being and pass on our biological legacy in good order to future generations. 

We can conserve biodiversity by following ways : 

(i) In situ conservation : It is the conservation of genetic resources within natural or human-made ecosystems in which they occur. e.g., protected areas such as national parks, sanctuaries, biosphere reserves, cultural landscapes, natural monuments. 

(ii) Ex situ conservation (off site) : It is the conservation of organisms outside their habitats, e.g., genetic resource centres, zoological parks, botanical gardens, gene banks, etc. 

(b) Biodiversity hotspots and sacred groves are the regions that are rich in biodiversity. A system with greater biodiversity is more stable and has greater productivity. Hence, biodiversity is related with overall health of our ecosystem and the survival of human race on the earth.

(i) Construction of such a highway will result in the fragmentation of the habitat and this will disrupt its continuity. The organisms will be confined to smaller area. The fragmentation reduces the amount of functional habitat, the species richness, taxon diversity and may also reduce the ecosystem functioning. Fragmentation also disrupts complex interactions amongst species. It results in annihilation of species and risk of their local extinction and thereby decreased biodiversity. 

(ii) The forests are useful to mankind in many ways. They provide us oxygen and help in bringing rain. They are the source of constructional material, industrial products and products of medicinal importance and also fire wood. They act as the habitat of a wide variety of flora and fauna, and keep the environment healthy. 

(iii) Values exhibited by Kalpna-awareness, love for nature, environmental consciousness, vision to foresee the disaster in the future.

If one species becomes extinct the plant or animal species associated with it in an obligatory way also becomes extinct e.g. when a fish species hosting a number of parasites gets extinct, the parasites species also dependent upon the host fish will also become extinct.

Earth's rich biodiversity is vital for the very survival of mankind. The reasons for conserving biodiversity are narrowly utilitarian, broadly utilitarian and ethical. Besides the direct benefits (food, fibre, firewood, pharmaceuticals, etc.), there are many indirect benefits we receives through ecosystem services such as pollination, pest control, climate moderation and flood control. Each and every living being has some intrinsic value. We derive countless economic benefits from the living things. Living things play a major role in many ecosystems. 

All the species in the ecosystem are interlinked. When a species becomes extinct, the plant and animal species associated with it in an obligatory way also becomes extinct. When a host fish species becomes extinct, its unique assemblage of parasites also meets the same fate. Another example is the case of coevolved plant - pollinator mutualism where extinction of one leads to extinction of the other.

Sacred groves are the areas of Aravalli Hills where forest patches around places of worship are held in high esteem by tribals. All the trees and wildlife are given protection by tribals. Not a single branch is allowed to be cut from these forests. As a result, many endemic species that are rare or have become extinct elsewhere can be seen to flourish here. Thus they help to conserve rare and threatened species of plants and animals. Ooty botanical garden conserves threatened and endangered species through ex-situ consevation technologies, involving seed bank, tissue culture facilities etc.