(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.
(a) Name any two places where it is essential to install electrostatic percipitators. Why is it required to do so?
(b) Mention one limitation of the electrostatic precipitator.
Prior to a sports event blood and urine samples of sports-persons are collected for drug tests.
(a) Why is there a need to conduct such tests/
(b) Name the drugs the authorities usually look for.
(c) Write the generic names of two plants from which these drugs are obtained.
Given below is a list of six micro-organism. State their usefulness to humans.
(a) Nucleopolyhedrovirus
(b) Saccharomyces cervisiae
(c) Monascus purpureus
(d) Trichoderma polysporum
(e) Peniciliu notatum.
(f) Propionibacterium sharmanni
Reproductive and Child Healthcare (RCH) programmes are currently in operation. One of the major tasks of these programmes is to create awareness amongst people about the wide range of reproduction related aspects. As this is important and essential for building a reproductively healthy society.
(a) Providing sex education in schools in one of the ways to meet this goal. Give four points in support of your opinion regarding this statement.
(b) List any two 'indicators' that indicate a reproductively healthy society.
Describe the experiment that helped demonstrate the semi-conservative mode of DNA replication
(a) Explain the post-pollination events leading to seed production in angiosperms.
(b) List the different types of pollination depending upon the source of pollen grains.
(a) Briefly explain the events of fertilisation and implantation in an adult human female.
(b) Comment on the role of placenta as an endocrine gland.
(a) How are the following formed and involved in DNA packaging in a nucleus of a cell?
(b) Differentiate between Euchromatin and Heterochromatin
(a) Represent diagrammatically three kinds of age-pyramids for the human population.
(b) How does an age pyramid for human population at given point of time helps the policy makers in planning for the future.
