The production of genetically modified (GM) or transgenic plants has several advantages.
(i) Most of the GM crops have been developed for pest resistance, which increases the crop productivity and therefore, reduces the reliance on chemical pesticides.
(ii) Many varieties of GM food crops have been developed, which have enhanced nutritional quality. For example, golden rice is a transgenic variety in rice, which is rich in vitamin A.
(iii) These plants prevent the loss of fertility of soil by increasing the efficiency of mineral usage.
(iv) They are highly tolerant to unfavourable abiotic conditions.
(v) The use of GM crops decreases the post harvesting loss of crops.
However, there are certain controversies regarding the use of genetically modified crops around the world. The use of these crops can affect the native biodiversity in an area. For example, the use of Bt toxin to decrease the amount of pesticide is posing a threat for beneficial insect pollinators such as honey bee. If the gene expressed for Bt toxin gets expressed in the pollen, then the honey bee might be affected. As a result, the process of pollination by honey bees would be affected. Also, genetically modified crops are affecting human health. They supply allergens and certain antibiotic resistance markers in the body. Also, they can cause genetic pollution in the wild relatives of the crop plants. Hence, it is affecting our natural environment.
Answer the following questions:
(a) [(i)] Explain how some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans but do not kill the Bacillus.
[(ii)] How is the above mechanism exploited for the production of Bt cotton plant by biotechnologists?
(b) [(i)] Explain how the amplification of gene of interest is done using PCR.
[(ii)] State two applications of the desired amplified fragment of DNA.
The basic scheme of the essential steps involved in the process of recombinant DNA technology is summarised below in the form of a flow diagram. Study the given flow diagram and answer the questions that follow.
(a) What is the technical term used for Step 4 in the above process?
(b) Which of the given two combinations of restriction enzyme should be used in Step 1? Justify your answer.
(i) EcoR I to cut the plasmid and Hind III to cut the alien DNA.
(ii) EcoR I to cut both the plasmid and alien DNA.
Biotechnology is the technology that utilizes biological systems, living organisms, or parts of this to develop or create different products.
For example, brewing and baking bread fall within the concept of biotechnology (use of yeast (= living organism) to produce the desired product).
Alternative to conventional farming: A possible solution is the use of genetically modified crops which is an alternative path to conventional farming.
In the area of healthcare, recombinant DNA technological processes have made an immense impact which enables the mass production of safe and more effective therapeutic drugs.
A collection of methods that allows the correction of a gene defect that has been diagnosed in a child/embryo is called Gene Therapy.
For editing genomes, CRISPR is a simple yet powerful tool which allows researchers to easily alter DNA sequences and modify gene function.