Many plant and animal species are on the verge of their extinction because of loss of forest land by indiscriminate use by the humans. As a biology student what method would you suggest along with its advantages that can protect such threatened species from getting extinct?

As a biology student, I would suggest the following methods to protect the threatened species from becoming extinct:

i. Ex situ conservation - The threatened species of plants and animals are taken out of their habitats and are kept in special settings such as zoological parks, botanical gardens and wildlife parks. This protects the organism, help maintain their number and prevent them from becoming extinct.

ii. Using the method like cryopreservation of the gametes of endangered species and their fertilization by the method of in-vitro fertilization. The use of tissue culture for propagation of the organism and the use of seed banks in case of plants. These methods allow us to preserve the genes of the endangered species and can be used to increase the number of endangered species by keeping the gamete or seeds viable and fertile for a longer period of time and using it when required.

iii We can lower the rate of deforestation avoiding indiscriminate use of forests and thus save the habitat of the species and protect them from extinction.


(a) What is El Nino effect? Explain how it accounts for biodiversity loss.

(b) Explain any three measures that you as an individual would take, to reduce environmental pollution.

(a) An El Nino event is a temporary change in the temperature, surface air pressure and currents of the Pacific Ocean in the region surrounding the equator. It affects both the ocean and atmosphere and can have major effects on the world's climate. El Nino causes global warming and the melting of polar ice cap. This leads to the submerging of coastal regions and loss of species endemic to that area. As El Nino also affects the ocean currents and causes sudden cooling or warming of the oceans, it leads to the death of marine life such as coral reefs and fishes as well. The depletion of coral reefs, in turn affects the life of other marine organisms that depend on the coral reefs for food and shelter.

(b) The measures that we as an individual can take in order to reduce environmental pollution can be

(i) Dumping of organic waste in places far from residential areas.

(ii) Using car pool so as to reduce pollution and fuel consumption.

(iii) Turning off air conditioners when not in use.

(iv) Planting more and more trees and reducing the deforestation.


'Bt' cotton is resistant to:

  • insects

  • Draught

  • salt

  • salt




(a) Why should we conserve biodiversity? How can we do it?
(b) Explain the importance of biodiversity hot-spots and sacred groves.

(a) Biodiversity conservation is necessary because of the following reasons:
i. Many commercially important products such as food, fibre and wood and countless industrial products are obtained from nature.
ii. Certain activities cannot be accomplished without the help of nature such as production of oxygen and pollination.
iii. Intangible benefits such as aesthetic pleasure are derived from nature.
iv. It is our duty to conserving the species we share our planet with and pass the biodiversity in a good condition to our future generations.

Biodiversity can be conserved by the following means:

In situ conservation - The organisms are conserved in their natural habitat. Certin areas are protected and prserved. In order to conserve biodiversity, some of the world’s biodiversity hotspots (with high degree of biodiversity and endemism) have been identified and are being protected. In India, biosphere reserves, wildlife sanctuaries and national parks are built for this purpose.

Ex-situ conservation - The threatened species of plants and animals are taken out of their habitats and are kept in special settings such as zoological gardens and wildlife parks.

Cryopreservation - Nowadays,the gametes of endangered parks, botanical species can be kept viable by preserving them at very low temperature with the help of liquid nitrogen.

(b) The hotspots are regions with high level of species richness and a high degree of endemism. Though these areas cover less than 2 percent of the earth's land are, the number of species they collectively harbour is extremely high ans trict protection of these hotpsots could reduce the mass extinction by almost 30 %. Thus, these areas are considered very important.

The sacred groves are the areas that are protected due to some religious or culttural beliefs. These are important as these are the last reges for a large number of rare and threatened plants.


Monadelphous Stamens are those which:

  • united into more than two bundles

  • united into two bundles

  • united into one bundle 

  • united into one bundle 


united into one bundle 


Determination of skin colour is an example of:

  • Co-dominance

  • polygenic inheritance

  • incomplete dominance

  • incomplete dominance


polygenic inheritance