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प्रश्न
Answer the following question.
How is a continuous culture system maintained in bioreactors and why?
उत्तर
In a continuous culture system, the used medium is drained out from one side while the fresh medium is added from the other to maintain the cells in their physiologically most active log/exponential phase. The continuous culture method produces larger biomass leading to a higher yield of the desired protein.
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संबंधित प्रश्न
What is a GMO?
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Answer the following question.
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Silencing of a gene could be achieved through tee use ______.
Assertion (A): In Bt cotton, B. thuringiensis produces a toxic insecticidal crystalline protein which destroys bollworms.
Reason (R): B. thuringiensis produces this toxic protein in an inactive form, but when an insect ingests this inactive protein, it is converted into active form of toxin due to the alkaline pH of gut which solubilises the crystals, which is responsible for the death of bollworm.
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Insects in the Lepidopteran group lay eggs on maize crops. The larvae on hatching feed on maize leaf and tender cob. In order to arrest the spread of three such Lepidopteran pests, Bt maize crops were introduced in an experimental field.
A study was carried out to see which of the three species of lepidopteran pests was most susceptible to Bt genes and its product.
The lepidopteran pests were allowed to feed on the same Bt-maize crops grown on 5 fields (A-E).
The graph below shows the leaf area damaged by these three pests after feeding on maize leaves for five days.
Key for lepidopteran insect pest species
 |
Species I |
 |
Species II |
 |
Species III |
Insect gut pH was recorded as 10, 8 and 6 respectively for Species I, II and III respectively.
(a) Evaluate the efficacy of the Bt crop on the feeding habits of the three species of stem borer and suggest which species is least susceptible to Bt toxin.
(b) Which species is most susceptible to Bt-maize, and explain why?
(c) Using the given information, suggest why a similar effect was not seen in the three insect species.
