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CHAPTER – 12, BIOTECHNOLOGY AND ITS APPLICATIONS, QUESTION BANK, SHORT ANSWER QUESTIONS, Q-1 Name a genus of baculovirus. Why are they consider, good bio control agent?, ANS: Nucleopolyhadrovirus is a genus of baculovirus. They, are species- specific, have narrow-spectrum insecticidal, application and no negative impact on non- target organisms,, hence they are considered good bio control agent. Q-2 How, has the bacterium Bacillus thuringiensis helped us in, controlling caterpillars of insect pests?, ANS: Bacillus thuringiensis products are endotoxin which, when ingested and release in the gut of the larvae of insect, pests disrupts the insects gut lining thereby killing them. Q-3, (a) Mention the cause and body system affected by ADA, deficiency in humans., (b) Name the vector used for transferring ADA-DNA into the, recipient cells in humans. Name the recipient cells., ANS: (a) The cause is the defective gene not producing ADA., The immune system is affected., (b) A retroviral vector is used, recipient cells are lymphocytes., Q-4 Describe the various stage involved in gene transfer for, the commercial production of human insulin by Eli Lilly. ANS:, (a) Eli Lilly prepared two DNA sequences corresponding to, the A and B chains of human insulin.
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(b) Sticky ends were produced in the Escherichiacoli, plasmid and the insulin gene by treating them both with the, same restriction endonucleases ., (c) These two are then joined together by the enzyme DNA, ligase., (d) The bacteria are then grown in sterilised bioreactors in, the appropriate growth medium., (e) The chains A and B are produced separately, extracted, and purified., (f) These two chains are then combined by creating, disulphide bonds to form human insulin., Q-5 (a) Give the scientific name of the soil bacterium which, produces crystal (Cry) proteins., (b) How are these proteins useful in agriculture? (c), What do the differently written terms ‘Cry’ and ‘cry’, represent respectively?, ANS: (a) Bacillus thuringiensis., (b) These Cry proteins are toxic to certain larvae of insects, and thus provide resistance against them. The gene encoding, Cry proteins are used in several crop plants (Bt toxin). Such a, crop plant is resistant to the particular insect pest., (c) Cry represents crystal protein while cry refers to the, gene encoding the Cry protein., Q-6 List the three molecular diagnostic techniques that help, detect pathogens from suspected patients. Mention one, advantage of these techniques over conventional method.
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ANS: The three molecular diagnostic techniques that help to, detect pathogens from suspected patients are:, (a) Recombinant DNA technology., (b) Polymerase chain reaction (PCR)., (c) Enzyme-linked immuno-sorbent assay (ELISA) . These, techniques are better than the conventional method, because they help in early diagnosis of the disease even, when the bacteria or virus concentration is very low.