Long Answer Type(a) How does the human body protect itself from infections ?.
(b) Write short notes on the following:
(i) Biomedical Engineering
(ii) Stem cells
(iii) Cryopreservation
(c) Give an account of Darwin’s finches.
(a) Explain the convergent and divergent evolution with suitable examples.
(b) What is manure? How does green manure differ from biofertilizers?
(c) What is IPM? Give an example of bioinsecticides and bioherbicides and how do they help in pest control.
(a) Convergent Evolution : It is similar adaptations for survival in similar habitats. It is also called parallel evolution, e. g., Some Marsupials of Australia resemble placental mammals that live in similar habitats on other continents. Australia separated from other continents more than 50 million years ago. Marsupials arrived in Australia before it separated and evolved in isolation even before the placental mammals. Natural selection has favoured changes that made the two groups more similar. Their phenotypes have converged.
Divergent evolution is also referred to as adaptive radiation. In it the original form of organisms migrated to and adapted to a different environment in different areas. They gradually changed and formed new species. Darwin’s finches, homologous organs are good examples of divergent evolution e. g., the forelimbs of mammals i. e., the scale of Whale, wings of bat leg of a horse, human hand, though different superficially and perform different functions but they have almost same structure. This shows adaptive radiations or divergent evolution from a common ancestor.
(b) Manures are the organic wastes which after partial decay are added to the soil to increase crop productivity.
Green Manure : Green manure consists of a quick growing crop which is cultivated and ploughed under the soil to provide organic matter and additional nitrogen to the soil.
Biofertilizers : Biofertilizers are organisms which bring about the nutrient enrichment of the soil.
(c) Integrated pest management is the selection, integration and implementation of pest control based on economic, ecological and sociological consequences.
Bioinsecticides – Bacillus thuringinsis
Bio herbicides – Cactoblastic cactorum or Phytophthora palmiora.
The biopesticidal approch mainly included sterilisation strategy.
(a) What is mental illness? Explain any three methods of treatment of mental illness.
(b) What are Koch’s postulates? Why are they not applicable to viruses?
(c) Name the causative agent and the main symptom of each of the following diseases :
(i) Filariasis
(ii) Rabies
(iii) Chicken pox
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