What is homologous recombination in the context of genetic engineering?
Answer: B
Homologous recombination uses regions of DNA sequence similarity (homologous arms) flanking the insert to direct accurate integration at specific chromosomal locations.
Q.22Medium
Which of the following is a limitation of first-generation gene therapy approaches?
Answer: A
Most first-generation gene therapy approaches target somatic cells to avoid heritable genetic modifications and ethical concerns associated with germline therapy.
Q.23Medium
What is the primary advantage of using viral vectors in gene therapy?
Answer: B
Viruses have naturally evolved sophisticated mechanisms to infiltrate cells and deliver their genetic material, making modified viral vectors efficient delivery systems for therapeutic genes.
Q.24Medium
In the context of genetically modified crops, what is substantial equivalence?
Answer: B
Substantial equivalence is a regulatory concept suggesting that if a GM crop is compositionally and nutritionally similar to its conventional counterpart, it can be considered equally safe.
Q.25Medium
Which bacterial species is commonly used as a host for expressing recombinant human proteins in industrial biotechnology?
Answer: B
E. coli is the preferred expression host for many therapeutic proteins including insulin and growth factors due to its rapid growth, well-characterized genetics, and established fermentation technology.
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Q.26Medium
What does 'mosaicism' refer to in the context of CRISPR gene editing outcomes?
Answer: B
Mosaicism occurs when CRISPR editing is performed early in development, resulting in some cells being edited while others retain the original genotype, creating a mixed population.
Q.27Medium
According to India's 2024 biosafety regulations, which committee approves field trials of genetically modified crops?
Answer: C
The GEAC, functioning under the MOEFCC, is the apex body responsible for appraisal and approval of proposals relating to release of GMOs and products into the environment.
Q.28Medium
Which of the following restriction enzymes produces sticky ends that are compatible with EcoRI sticky ends?
Answer: C
MboI produces sticky ends identical to EcoRI due to recognition of similar DNA sequences (GATC), making them compatible for ligation.
Q.29Medium
In Bt cotton cultivation in India, the Cry1Ac toxin primarily targets which insect order?
Answer: A
Cry1Ac toxin from Bacillus thuringiensis specifically targets lepidopteran pests like cotton bollworms. It binds to specific receptors in their midgut.
Q.30Medium
Which technique is used to identify whether a gene sequence contains introns and exons in eukaryotic organisms?
Answer: B
Heteroduplex analysis uses electron microscopy to visualize DNA-RNA hybrids. Introns form loops that are clearly visible, confirming their presence.
Q.31Medium
According to India's National Biotechnology Development Strategy 2024, which sector receives the highest allocation for gene therapy research?
Answer: B
India's 2024 strategy prioritizes gene therapy for rare genetic disorders to address unmet medical needs and reduce disease burden in economically disadvantaged populations.
Q.32Medium
In homologous recombination-based gene editing, what is the primary advantage of using long homology arms (>1 kb) flanking the insert?
Answer: B
Longer homology arms (typically 1-2 kb) provide greater sequence identity for recombination machinery recognition, increasing efficiency and reducing off-target integration.
Q.33Medium
Which of the following genetically modified crops has been approved for commercial cultivation in India as per GEAC regulations (2024)?
Answer: D
As of 2024, Bt Cotton remains approved, and Bt Chickpea received commercial approval in 2023-24. Golden Rice and herbicide-resistant crops have not been approved in India.
Q.34Medium
In insulin production using genetically engineered E. coli, why is the use of proinsulin preferred over direct insulin gene expression?
Answer: C
E. coli lacks proteases and post-translational modification machinery. Proinsulin can fold properly in bacteria; it's then enzymatically cleaved to produce mature, bioactive insulin.
Q.35Medium
Which of the following represents an application of TALEN technology that has shown clinical promise in 2024?
Answer: A
TALENs have been explored for editing CCR5 in HIV therapy, mimicking natural CCR5-Δ32 deletion. This approach shows potential for functional HIV resistance without integration risks.
Q.36Medium
According to India's DBT 2024 guidelines, what is the mandatory holding period for biosafety assessment of genetically modified crops before large-scale field trials?
Answer: C
India's current biosafety framework mandates 2-3 years of phased trials (contained use, limited field trials, then large-scale) before product approval, ensuring thorough risk assessment.
Q.37Medium
In synthetic biology, what is the primary advantage of using BioBricks standardized parts over conventional genetic engineering?
Answer: B
BioBricks provide standardized interfaces (RFC10 standards) for combining biological parts into systems, enabling composable genetic design, rapid iteration, and community resource sharing.
Q.38Medium
Which vector is most commonly used for large DNA inserts (up to 45 kb) in genetic engineering?
Answer: C
BACs can accommodate inserts of 100-300 kb, while cosmids can hold up to 45 kb. For large inserts, BACs are superior to plasmids (typically 15-20 kb) and phagemids.
Q.39Medium
In CRISPR-Cas9 technology, what is the function of the guide RNA (gRNA)?
Answer: B
The guide RNA is complementary to the target DNA sequence and directs the Cas9 nuclease to the correct location for DNA cleavage.
Q.40Medium
Which of the following is a homologous recombination-based gene editing technique?
Answer: B
Gene targeting uses homologous recombination to introduce specific changes at exact genomic locations, while CRISPR, TALENs, and ZFNs create double-strand breaks that are repaired by non-homologous end joining.
