Please provide the answer to these questions very urgently!!!

Dear student,
Please find below the answer:

1. Biotechnology is useful in many ways. For example, Agriculture (making disease-free, stable plants, fruits & vegetables), Food, medicine, forensics etc.
But it can be misused because it gives an insight into the genes and genetical information of an individual. Also the cloning process involved in it can be performed against law. Biotechnological methods create genetically engineered food products. This may create, ethical, physical problems to humans.

2. Making of Bt-cotton.
  • Bacillus thuringiensis is a bacterium that produces proteins which kill certain insects like armyworm, beetles, flies/ mosquitoes etc. B. thuringiensis produces a protein crystal which contains a toxic protein in an inactivated state.
    Inactivated toxinActivated toxin (gut of insect)

  • The toxin that gets activated binds to the epithelial cells present in the midgut of insect. This creates pores that cause lyses, swelling and eventually the death of the insect.

    ​​​This toxin gets encoded by Cry, a gene present in the bacterium. Genes which get encoded by Cry IAc and Cry II Ab help in controlling cotton bollworms and those encoded by Cry IAb help in controlling corn borer.

The Cry genes from the bacterium are introduced into the cotton plants. This results in the production of Bt cotton, which is an insect-resistant variety of cotton plant. The steps involved in its production are as follows:

  • Isolation of the Cry Genes encoding toxin from the Bacillus thuringiensis.
  • Introduction of these genes into the plant cells. This is done by using the Agrobacterium tumefaciens. This bacteria is a natural pathogen of plants and causes tumour called crown gall disease in plants. The Cry genes are introduced into plasmid of this bacteria by genetic engineering and it is allowed to infect the plant. In this way, it introduces the genes of Bt which produce toxins along with its own plasmid into plant cells.

After these genes are introduced into plant cells, they express themselves and produce the toxin crystals in the plant which causes the death of insects when they feed on them. 

Hope this clears your doubt.
Regards.

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