In situ conservation can help endangered / threatened species. J

Subject

Biology

Class

CBSE Class 12

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Sample Papers

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 Multiple Choice QuestionsShort Answer Type

21.

Why do lepidopterans die when they feed on Bt cotton plant? Explain how does it happen.

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22.

In situ conservation can help endangered / threatened species. Justify the statement.


In situ conservation involves the protection of species in their natural habitats. It helps in the conservation of
threatened/endangered species via following means :
(i) Biodiversity hotspots are regions with high levels of species richness and high degree of endemism (i.e. species confined to that region are not found anywhere else). Hotspots cover less than 2% of the earth’s land area.
(a) The total number of biodiversity hotspots in the world are 34.
(b) These hotspots are regions of accelerated habitat loss.
(c) Three hotspots which cover India’s biodiversity regions are Western Ghats and Sri Lanka, Indo-Burma and Himalaya.
(d) These hotspots can reduce the ongoing mass extinctions by almost 30%.
(ii) Protected areas are ecologically unique and biodiversity rich regions. These are legally protected as biosphere reserves, national parks and sanctuaries.
(a) India has 14 biosphere reserves, 90 national parks and 448 wildlife sanctuaries.
(b) The first national park set up in India was Jim Corbett National Park.
(iii) Sacred groves are forest areas set aside, all the trees and wildlife within it are venerated and given total protection. These are religious and cultural places, which are protected. Some of the sacred groves in India are: Western Ghat regions of Karnataka and Maharashtra.
Khasi and Jaintia Hills in Meghalaya. Aravalli Hills of Rajasthan. Sarguja, Chanda and Bastar areas of Madhya Pradesh.

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 Multiple Choice QuestionsLong Answer Type

23.

Public all over India is very much concerned about the deteriorating air quality in large parts of North India. Alarmed by this situation the Resident’s Welfare Association of your locality organised an awareness programme entitled ‘Bury not burn’. They invited you, being a biology student to participate.
(a) How would you justify your arguments that promote burying and discourage burning?
(Give two reasons)
(b) With the help of flow charts, one for each practice, depict the chain of events that follow.

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24.

(a) Arrange the following hormones in the sequence of their secretion in a pregnant woman.
(b) Mention their source and the function they perform.

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25.

State and explain the ‘law of independent assortment’ in a typical Mendelian dihybrid cross.

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26.

Discuss the role of healthy ecosystem services as a prerequisite for a wide range of economic, environmental and aesthetic goods and services.

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