Long Answer TypeMass Selection : In this selection large number of similarl plants are selected for the desired trait and their seeds are mixed together. The mixture of seeds so obtained is sown to raise the new crop.
Pure line selection : The pure line is the progeny of a single homozygous self pollinated plant. The single plants with desired trait are selected out of the variable polulation in the field. Desired plants are again selected from this progeny and self-pollinated.
Pure line selection is better than mass selection because the selected plants retain desirable character for several generations.
(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) 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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