Short Answer TypeDarwin's theory of natural selection is a process in which the organisms which have favourable variations in order to survive in the changed environment are selected by the nature to continue their generations and the rest fail to survive. Industrial melanism also showed the same case as was explained by Darwin’s theory of natural selection.
Industrial melanism - In England, it was noted that before industrial revolution, the number of white-winged moths was much more than that of dark melanised moth. However, after industrialisation, the number of dark moths increased. This happened because; the industrialization caused the tree trunks to become darker with deposits of soot and smoke. Hence, the dark moths increased as they escaped the predators as they were not easily visible while the white-winged ones were easily picked up. Thus, dark ones were selected by nature (natural selection) and light ones failed to survive.(a) Tobacco plants are damaged severely when infested with Meloidegyne incognitia. Name and explain the strategy that is adopted to stop this infestation.
(b) Name the vector used for introducing the nematode specific gene in tobacco plant.(a) Explain the phenomena of multiple allelism and co-dominanace taking ABO blood group as an example.
(b) What is the phenotype of the following:(i) IAi
(ii) i i
(a) List any three ways of measuring population density of a habitat.
(b) Mention the essential information that can be obtained by studying the population of an organism.(a) What is the programme called that is involved in improving success rate of production of desired hybrid and herd size of cattle?
(b) Explain the method used for carrying this programme for cows.
Long Answer Type(a) Explain the significance of ecological pyramids with the help of an example.
(b) Why are the pyramids referred to as upright or inverted?
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