Short Answer Type(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) Population density means number of individuals present per unit area. We can find out population density of a habitat by determining the population size. The different methods to study population size are as follows:-
(1) Total number: In this method the total number of organism in the population is counted. For example, in order to determine the number of bacteria growing in a Petri dish, their colonies are counted.
(2) Relative densities- In this method relative density of the population is taken into account rather than counting the total number. For example - The number fish caught per trap gives the measure of their total population density in the given water body.
(3) Percent cover or biomass cover: For example in a population of 200 Parthenium plants and a single huge Banyan tree the percent cover of both are taken into account.
(b) The study of population tells us a lot about the status of the species in the habitat. It tells us about -:
(i)The outcome of competition with another species.
(ii) The impact of a predator.
(iii) The effect of a pesticide application .
(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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