$$ \text { A patient is suffering from ADA deficiency. Can he be cured? How? } $$
ADA enzyme is crucial for the immune system to function. Deletion of the gene for adenosine deaminase results into ADA deficiency.
In some children, ADA deficiency can be cured by bone-marrow transplantation, while in others it can be treated by enzyme replacement therapy, in which functional ADA is given to the patient by injection. But the problem with both of these approaches is that they are not completely curative.
It may recurrent in nature as in the process of gene therapy, lymphocytes used are found not to be immortal in nature and the patient requires a periodic infusion of such genetically engineered lymphocytes.
For permanent cure, gene isolated from the bone-marrow cells producing ADA is introduced into cells at early embryonic stages.
Define transgenic animals. Explain in detail any four areas where they can be utilised.
Animals that have had their DNA manipulated to possess and express an extra (foreign) gene are known as transgenic animals.
Following are the four main areas where they can be utilised
(i) To Study Normal Physiology and Development
These animals can be used to study that which factor/gene products are needed at what time of development. By the expression of certain genes, they help scientists to understand the normal gene expression at various stages of growth and development.
(ii) Study of Diseases
Transgenic animals can be created to serve as models for various human diseases. They also help us to understand the involvement of various genes in diseases like cancer, Parkinson' disease etc.
(iii) Vaccine Safety
Transgenic animals can be used to test vaccines like polio vaccine. Transgenic mice have shown promising results in this area and would replace the vaccine testing on monkeys in the years to come.
(iv) Chemical Safety Testing
Transgenic animals are created which are more sensitive to certain chemicals/drugs. These are used to study the toxicity or side effects of that chemical/drug. The advantage is that we get results faster.
You have identified a useful gene in bacteria. Make a flow chart of the steps that you would follow to transfer this gene to a plant.
After identifying a useful gene in bacteria, following steps should be followed
(i) Isolation of useful gene using restriction endonucleases
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(ii) Transferring the gene to a suitable vector to create a recombinant DNA molecule
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(iii) Transfer of these recombinant DNA molecules to the target cells.
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(iv) Screening of cells for transformation
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(v) Selection of transformed cells
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(vi) Regeneration of plants from the transformed cells to get transgenic plants.
Highlight five areas where biotechnology has influenced our lives.
Biotechnology has influenced our lives in the following ways
(i) It has provided us with genetically modified crops of better quality and high nutritive value.
(ii) It has made better and safer recombinant vaccines available to the human.
(iii) It has helped to develop transgenic animals that can produce human proteins.
(iv) It has enabled the cure of genetic diseases using gene therapy.
(v) Environment pollution has also been taken care of with the help of genetically engineered microbes.
What are the various advantages of using genetically modified plants to increase the overall yield of the crop?
Genetically modified plants have been useful in many ways as follows
(i) These plants are more tolerant to abiotic stresses (cold, drought, salt, heat).
(ii) They have reduced the reliance on chemical pesticides (pest-resistant crops).
(iii) They helped to reduce post harvest losses.
(iv) They increases the efficiency of mineral usage by plants (this prevents early exhaustion of fertility of soil).
(v) Enhanced nutritional value of food, e.g., vitamin-A enriched rice.
In addition to these uses, GM plants have been used to create tailor-made plants to supply alternative resources to industries, in the form of starches, fuels and pharmaceuticals.