Applications Of Biotechnology

Bt cotton is a genetically modified (GM) variety of cotton that has been developed to resist insect pests, especially the bollworm, which causes severe damage to cotton crops.

Step 1: Development.
The gene for Cry protein was taken from the bacterium Bacillus thuringiensis (Bt). This gene was inserted into cotton plants through genetic engineering.

Step 2: Mode of Action.
The Cry protein, when ingested by insect larvae, gets activated in their alkaline gut. The protein binds to the gut lining, creating pores, which ultimately leads to the death of the pest.

Step 3: Benefits.

Step 4: Limitations.
Excessive and continuous use of Bt cotton may lead to the development of resistance in pests. It also raises concerns about biodiversity and ecological balance.

Step 1: Understanding Genetic Engineering.
Genetic engineering involves the manipulation of an organism's DNA to introduce desirable traits, cure diseases, or enhance productivity.

Step 2: Applications in Medical Treatment.
In medicine, genetic engineering is used in gene therapy, production of insulin, vaccines, monoclonal antibodies, and treatment of genetic disorders.

Step 3: Applications in Agriculture.
In agriculture, it is used to create genetically modified (GM) crops such as Bt cotton, Bt maize, and Golden Rice, which are pest-resistant or nutritionally enriched.

Step 4: Conclusion.
Since genetic engineering is applied in both medical treatment and agriculture, the correct option is (C) Both (A) and (B).

DNA fingerprinting is a technique used to identify individuals based on their unique DNA sequence patterns. It was developed by Alec Jeffreys in 1984. In India, it was pioneered by Dr. Lalji Singh, known as the "Father of DNA Fingerprinting in India." Principle: It is based on the polymorphism in repetitive DNA sequences, particularly VNTRs (Variable Number of Tandem Repeats) that vary from individual to individual. Steps of DNA Fingerprinting: \begin{enumerate} \item DNA Isolation: Extraction of DNA from cells such as blood, hair root, or saliva. \item Restriction Digestion: DNA is cut into fragments using restriction endonucleases. \item Separation: Fragments are separated by gel electrophoresis. \item Hybridization: Fragments are transferred to a nylon membrane and hybridized with radioactive DNA probes specific to VNTRs. \item Autoradiography: The pattern of bands obtained on X-ray film represents the DNA fingerprint. \end{enumerate} Applications:

Earlier, insulin for diabetic patients was extracted from the pancreas of cattle and pigs. However, it had several drawbacks: \begin{enumerate} \item Immunological reactions: Animal insulin differed slightly in amino acid sequence from human insulin, sometimes causing allergic reactions or immune responses in patients. \item Risk of infections: There was a possibility of transmitting animal-borne pathogens and contaminants through animal-derived insulin. \item Limited supply and cost: Large numbers of animals had to be slaughtered to obtain small amounts of insulin, making the process costly and unsustainable. \end{enumerate} Conclusion.
These drawbacks were overcome by developing recombinant human insulin using genetically engineered E. coli, which is safer, cheaper, and identical to natural human insulin.

Human insulin production by recombinant DNA (rDNA) technology is a major achievement in biotechnology. It is used to treat diabetes mellitus.

Step 1: Identification of Gene.
The gene responsible for insulin production is identified from human DNA. Insulin consists of two polypeptide chains – A and B.

Step 2: Insertion into Plasmid.
The insulin gene is inserted into a plasmid vector (circular DNA from bacteria) using restriction enzymes. This recombinant plasmid is then introduced into E. coli bacteria.

Step 3: Expression in Host.
The bacteria, now genetically engineered, produce insulin polypeptides (A and B chains) as they multiply.

Step 4: Extraction and Purification.
The insulin chains produced by bacteria are extracted, purified, and then chemically combined to form functional human insulin.

Step 5: Use in Medicine.
The recombinant human insulin is marketed as "Humulin" and widely used by diabetic patients.

Step 1: Definition.
Bio-fertilizers are living microorganisms which, when applied to seeds, plant surfaces, or soil, promote growth by increasing the availability of essential nutrients to plants.

Step 2: Examples of bio-fertilizers.

Step 3: Role in food production.
Conclusion.
Bio-fertilizers are essential for eco-friendly, sustainable agriculture and play a vital role in ensuring long-term food security.

The father of the Green Revolution in India is Dr. M. S. Swaminathan.

Step 1: Understanding the Green Revolution.
The Green Revolution refers to the period during the 1960s and 1970s when agriculture in India was transformed by the introduction of high-yielding varieties (HYVs) of seeds, chemical fertilizers, pesticides, irrigation methods, and mechanization. This significantly increased agricultural productivity, especially in wheat and rice.

Step 2: Role of Dr. M. S. Swaminathan.
- Dr. Swaminathan, an Indian geneticist and agricultural scientist, collaborated with Norman Borlaug (known as the father of the global Green Revolution) to bring HYV seeds of wheat to India. - He adapted these seeds to Indian conditions and guided large-scale implementation. - With his vision and leadership, India moved from a food-deficient country to becoming self-sufficient in food grain production.

Step 3: Impact of the Green Revolution.
- Helped India overcome famine-like conditions during the 1960s. - Improved food security and reduced dependence on food imports. - Marked the beginning of modern scientific farming in India. - However, it also led to environmental concerns such as soil degradation, excessive use of fertilizers and pesticides, and reduced crop diversity.

Step 4: Recognition.
For his immense contribution, Dr. M. S. Swaminathan is honored with the title "Father of Green Revolution in India". He also received global recognition and awards for his service in agricultural development and food security.

Step 1: Understanding genetically modified (GM) plants.
Genetically modified plants are those in which specific genes have been inserted to improve traits such as pest resistance, disease resistance, or nutritional quality. One common modification is the introduction of the Bacillus thuringiensis (Bt) gene, which produces a toxin harmful to insects but safe for humans.

Step 2: Analysis of options.
- (A) BT maize: This is a genetically modified maize that contains the Bt gene for insect resistance.
- (B) BT cotton: One of the most widely used GM crops, Bt cotton resists bollworm pests.
- (C) BT rice: Research has developed Bt rice for resistance against stem borers.
- (D) All of these: Since all the above-mentioned plants are genetically modified, this is correct.

Step 3: Conclusion.
The correct answer is (D) All of these, because Bt maize, Bt cotton, and Bt rice are all genetically modified plants.