Biotechnology: UPSC Previous Year Questions (Science and Technology)

Explanation

DNA fingerprinting is biotechnique based on analysis of specific regions of DNA that are unique to each individual. This makes it a powerful forensic tool. Assertion (A) is true: DNA fingerprinting, also known as DNA profiling, has become a powerful tool in forensic science for identifying individuals. It is widely used to establish paternity and to identify suspects in criminal cases, including rape and assault. The unique genetic makeup of each individual allows forensic experts to match DNA samples from crime scenes with those of suspects or to determine biological relationships. Reason (R) is true: Trace evidence such as hair, saliva, and dried semen can provide sufficient DNA for analysis. Even small biological samples left at crime scenes can be collected and processed to extract DNA, which can then be compared to known samples to identify individuals. Both Assertion (A) and Reason (R) are true, and Reason (R) correctly explains why DNA fingerprinting is effective in establishing paternity and identifying criminals in rape and assault cases. The ability to analyze DNA from minimal trace evidence underpins the power of DNA fingerprinting in forensic investigations.

Explanation

Insect-resistant cotton, commonly known as Bt cotton, has been genetically engineered by inserting a gene from the bacterium Bacillus thuringiensis (Bt). This bacterium naturally produces a protein toxic to specific insect pests, such as bollworms, but is safe for humans and non-target organisms. The Bt gene produces a protein that disrupts the digestive system of the pests upon ingestion, ultimately killing them. Bt cotton has significantly reduced the dependence on chemical insecticides and has become a widely adopted technology for pest management in cotton farming.

Explanation

Option (a) is correct: Hybridoma technology is a groundbreaking biotechnological method developed for the large-scale production of monoclonal antibodies. This technique involves the fusion of an antibody-producing B lymphocyte with a myeloma (cancer) cell, creating a hybrid cell line called a hybridoma. These hybridomas are capable of producing a single type of antibody (monoclonal) indefinitely. Monoclonal antibodies are widely used in medical diagnostics, treatment of diseases such as cancer and autoimmune disorders, and in research applications. Options (b), (c) and (d) are incorrect:

Interferons, are proteins used in antiviral therapies. They are not produced using hybridoma technology. They are typically synthesized using recombinant DNA technology. Antibiotics are derived from microorganisms like fungi and bacteria, not via hybridoma technology. Alcohol production relies on fermentation processes, not hybridoma technology.