VBQs Class 12 Biology Biodiversity and Conservation
Very Short Answer Type Questions
Question. Why have Western Ghats in India been declared as biological hot spots ?
Answer : Due to greater species diversity/presence of endemic species.
Question. State the use of biodiversity in modern agriculture.
Answer : Biodiversity is useful in modern agriculture because it is source of hybrids, GM Crops, biopesticides, biofertilizers, improved variety of plants and also disease resistant plants.
Short Answer Type Questions
Question. List any four techniques where the principle of ex-situ conservation of biodiversity has been employed.
State how does ex-situ conservation help in protecting biodiversity.
Answer : Cryopreservation, in vitro fertilisation, micropropagation / tissue culture, sperm bank / seed bank / gene bank
Detailed Answer :
Four techniques where the principle of exsitu conservation of bio-diversity has been employed are as follows :
(i) Preservation of the gametes of threatened species (using cryopreservation technique) in viable and fertile condition for long periods.
(ii) In vitro fertilization of eggs.
(iii) Propagation of plants using tissue culture technique.
(iv) Keeping the seeds of different genetic strains that are commercially important plants for long period in seed bankers.
Question. Suggest two practices giving one example of each, that help protect rare or threatened species.
Answer : (i) In situ conservation, biodiversity hotspot / biosphere reserve / national parks / sanctuaries / Ramsar sites / sacred groves
(ii) Ex situ conservation, Zoological parks / botanical garden / wild life safari parks / cryopreservation techniques / Tissue culture / seed bank / pollen banks.
Question. Narrowly utilitarian arguments are put forth in support of biodiversity conservation. Explain the other two arguments that are put forth in support of the same cause.
Answer : Broadly utilitarian arguments : Biodiversity plays an important role in maintaining sustaining supply of good & ecological services.
The different ecosystem services provided are :
purifies air, cycling of nutrients, habitat for wildlife, pollinating crops, aesthetic pleasure.
Ethical reasons :
It is our philosophical/spiritual & moral duty to ensure well being of all living beings for utilization of future generations.
Question. There are many animals that have become extinct in the wild but continue to be maintained in Zoological parks.
(i) What type of biodiversity conservation is observed in this case ?
(ii) Explain any other two ways that help in this type of conservation.
Answer : (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 care.
(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.
Question. The sacred groves of Aravalli Hills and Ooty botanical garden both aim at biodiversity conservation. How do they differ in their approached ? Explain.
Answer : 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 conservation technologies, involving seed bank, tissue culture facilities etc.
Question. ‘In-situ‘ conservation can help endangered / threatened species. Justify the statement.
Answer : Threatened organisms are conserved in their natural habitat / ecosystem, and such regions are legally protected
As hotspots / biosphere reserves / national parks / sanctuaries / sacred groves / ramsar sites
Detailed Answer :
In-situ conservation 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 landscape, national monuments etc.
Long Answer Type Questions
Question. (i) Why should we conserve biodiversity ? How can we do it ?
(ii) Explain the importance of biodiversity hot spots and sacred groves.
Answer : (i) (a) • Narrowly utilitarian – related examples like derive economic benefits from nature: food (cereals, pulses, fruits) / firewood / fibre / construction materials / industrial products (tannins, lubricants, dyes, 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 / we have a moral duty to care for their well-being and pass on our biological legacy to future generations.
(b) • In situ conservation / biosphere reserves / national parks / sanctuaries / sacred groves.
• Ex situ conservation / zoological parks / botanical gardens / wild life safari parks / cryopreservation / seed banks / tissue culture (eggs in vitro)
(ii) 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 a large number of rare, and threatened plants.
Detailed Answer :
(i) We should conserve bio-diversity because of the following reasons :
(a) Humans derive countless economic benefits from nature like
• Food (cereals, pulses, fruits)
• Wood, fibre, construction material, industrial products (tannins, lubricants, dyes, resins, perfumes)
• Products of medicinal importance
(b) Biodiversity plays a major role in many ecosystem services that nature provides such as production of oxygen and pollination.
(c) 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 :
(a) In situ conservation : It is the conservation of genetic resources within natural or humanmade ecosystems in which they occur. e.g., protected areas such as national parks, sanctuaries, biosphere reserves, cultural landscapes, natural monuments.
(b) 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.
(ii) 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.