|1. GM crops are developed for pest resistance and thus the yield increases and there is less dependence on pesticides.||1. GM crops that show pest resistance prove harmful for pollinators and hence pollination.|
|2. GM crops are developed to increase the nutritional value in the crops.||2. GM crops can lead to severe allergies in some and may not be as good in taste as the natural crop.|
|3. They can be used to develop crops which are more tolerant to abiotic stresses||3. The pollen of GM crops is also modified and can lead to the development of resistance and growth of super-weeds. Weeds prove harmful to the environment and crops.|
|4. GM crops can be developed to have antibiotic properties||The intake of GM crops having antibiotic properties may lead to antibiotic resistance in some and less efficacy of antibiotic medications.|
|5. GM crops can be modified to benefit humans.||5. The patent provided for the development of GM crops has been creating problems because the companies are benefited while the farmers are at loss.|
What are Cry proteins? Name an organism that produce it. How has man exploited this protein to his benefit?
Example. Transgenic bacteria like E.coli which produces insulin. This bacteria is genetically manipulated by introducing two DNA sequences corresponding to A and B chains of human insulin in plasmids of E. coli to produce insulin chains. Chains A and B produced separately are extracted and combined by disulfide bonds to form human insulin.
Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because
C.toxin is inactive
What is gene therapy? Illustrate using the example of adenosine deaminase (ADA) deficiency.
Gene Therapy. It is defined as the introduction of a normal functional gene into cells which contain the defective gene with the objective of correcting a gene defect that has been diagnosed in a child/embryo.
For example - Treatment of ADA deficiency by gene therapy. Adenosine deaminase is an enzyme crucial for funtioning of immune system. Gene therapy has been used to cure the deficiency of ADA enzyme
1. By growing the lymphocyte from blood cells of patient in culture outside the body.
2. A funtional ADA gene is introduced in the cultured lymphocyte using retrovirus.
3.The transformed lymphocytes are then returned to the patient.
4. Thus the cells now contain funtional gene for the enzyme and deficiency is cured.