Introduction: Transgenics and genomic analysis are core topics for B. Pharm students exploring genetic engineering, recombinant DNA technology, and pharmacogenomics. This introduction links transgenic organism creation, vector design, gene expression regulation, and genomic tools like PCR, sequencing, microarrays, and CRISPR-Cas systems. Understanding genotyping, reporter assays, protein expression, and bioinformatic analysis is essential for drug discovery, safety assessment, and biomarker identification. Practical knowledge of selection markers, promoters, homologous recombination, viral and nonviral delivery, and off-target effects prepares students for research and regulatory challenges. Emphasis on ethical, biosafety, and clinical translation aspects connects theory to pharmacy practice. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which element in a transgenic vector ensures high-level constitutive expression of a recombinant gene in mammalian cells?
- Shine-Dalgarno sequence
- SV40 promoter
- T7 promoter
- Origin of replication
Correct Answer: SV40 promoter
Q2. What is the main advantage of using CRISPR-Cas9 over traditional homologous recombination for generating gene knockouts?
- CRISPR requires longer homology arms
- CRISPR introduces double-strand breaks at defined loci with higher efficiency
- CRISPR never creates off-target effects
- CRISPR uses viral vectors exclusively
Correct Answer: CRISPR introduces double-strand breaks at defined loci with higher efficiency
Q3. In designing a transgenic plant expressing a therapeutic protein, which strategy most improves soluble expression and correct folding?
- Use of strong bacterial promoter
- Targeting protein to endoplasmic reticulum with signal peptide
- Omitting all post-translational modification signals
- Expressing protein only in roots
Correct Answer: Targeting protein to endoplasmic reticulum with signal peptide
Q4. Which technique provides genome-wide gene expression profiling to compare transgenic and wild-type samples?
- Southern blot
- DNA microarray or RNA-seq
- Restriction fragment length polymorphism (RFLP)
- ELISA
Correct Answer: DNA microarray or RNA-seq
Q5. What is the principle of quantitative real-time PCR (qPCR) used in genomic analysis?
- Detection of DNA fragments after gel electrophoresis only
- Real-time measurement of amplified product using fluorescent reporter dyes or probes
- Quantification by colony counting
- Measuring protein levels with antibodies
Correct Answer: Real-time measurement of amplified product using fluorescent reporter dyes or probes
Q6. Which selectable marker is commonly used for selecting transgenic bacteria carrying a plasmid vector?
- Green fluorescent protein (GFP)
- Ampicillin resistance gene (bla)
- Poly-A tail
- Lac promoter
Correct Answer: Ampicillin resistance gene (bla)
Q7. Which method is most appropriate for confirming the integration site of a transgene in a transgenic animal?
- Western blot of serum proteins
- Fluorescent in situ hybridization (FISH) or genome sequencing
- Mass spectrometry of metabolites
- Chromatography
Correct Answer: Fluorescent in situ hybridization (FISH) or genome sequencing
Q8. What is an important ethical/regulatory concern specific to creating transgenic organisms for pharmaceutical proteins?
- Inability to sequence DNA
- Potential environmental release and gene flow to wild populations
- No requirement for clinical trials
- Elimination of all immune responses
Correct Answer: Potential environmental release and gene flow to wild populations
Q9. In genomic variant analysis, what does SNP stand for and why is it important in pharmacogenomics?
- Single Nucleotide Polymorphism; influences drug response and metabolism
- Single Nuclear Protein; determines protein folding
- Specific Nucleotide Position; only relevant in bacteria
- Small Nuclear Peptide; involved in signaling
Correct Answer: Single Nucleotide Polymorphism; influences drug response and metabolism
Q10. Which viral vector is commonly used for stable gene delivery into dividing and non-dividing mammalian cells with relatively large cargo capacity?
- Adeno-associated virus (AAV)
- Lentiviral vector
- Bacteriophage lambda
- SV40
Correct Answer: Lentiviral vector
Q11. Which assay is most suitable for detecting transgene copy number in a genetically modified crop?
- qPCR copy number assay
- Northern blot for RNA
- SDS-PAGE
- ELISPOT
Correct Answer: qPCR copy number assay
Q12. What role do promoters like CMV and EF1α play in expression vectors?
- They are origins of replication for bacterial growth
- They drive transcription initiation and determine expression strength in eukaryotic cells
- They encode antibiotic resistance
- They prevent mRNA translation
Correct Answer: They drive transcription initiation and determine expression strength in eukaryotic cells
Q13. Which sequencing technology is best for whole-genome variant discovery with short read lengths and high throughput?
- Sanger sequencing
- Next-generation sequencing (Illumina short reads)
- Nanopore single-molecule long reads only
- Edman degradation
Correct Answer: Next-generation sequencing (Illumina short reads)
Q14. What is the purpose of using a reporter gene like luciferase or GFP in transgenic constructs?
- To confer antibiotic resistance
- To visually or quantitatively monitor promoter activity and expression
- To inhibit transcription
- To act as a secretion signal
Correct Answer: To visually or quantitatively monitor promoter activity and expression
Q15. In RNA interference (RNAi) approaches for gene silencing, which molecule mediates sequence-specific mRNA degradation?
- siRNA or miRNA incorporated into RISC complex
- Double-stranded DNA only
- Ribosomal RNA binding factor
- Chaperone proteins
Correct Answer: siRNA or miRNA incorporated into RISC complex
Q16. Which post-translational modification frequently affects the bioactivity and immunogenicity of recombinant therapeutic proteins produced in non-mammalian systems?
- Phosphorylation patterns identical to human
- Non-human glycosylation leading to altered immunogenicity
- Enhanced lipidation improving oral absorption
- Complete absence of disulfide bonds only
Correct Answer: Non-human glycosylation leading to altered immunogenicity
Q17. For validating transgene expression at the protein level, which method directly measures specific protein presence and size?
- Northern blotting
- Western blotting
- Southern blotting
- PCR amplification
Correct Answer: Western blotting
Q18. What is an off-target effect in CRISPR-Cas genome editing and why is it a concern?
- Desired mutation at target locus; enhances efficacy
- Unintended edits at similar genomic sites; can disrupt other genes and cause safety issues
- Enhanced specificity to target sequence only
- Only occurs in bacterial systems
Correct Answer: Unintended edits at similar genomic sites; can disrupt other genes and cause safety issues
Q19. Which method is commonly used to detect transgene mRNA levels and splicing variants?
- Chromatin immunoprecipitation (ChIP)
- Reverse transcription PCR (RT-PCR) and RNA-seq
- Southern blot
- Mass spectrometry of DNA
Correct Answer: Reverse transcription PCR (RT-PCR) and RNA-seq
Q20. In molecular cloning, why is codon optimization performed when expressing a human gene in E. coli?
- To reduce protein yield deliberately
- To match host tRNA abundance and improve translation efficiency
- To add introns for stability
- To eliminate start codons
Correct Answer: To match host tRNA abundance and improve translation efficiency
Q21. Which technique separates DNA fragments based on size for analyzing restriction digests or PCR products?
- Gel electrophoresis
- Flow cytometry
- ELISA
- Spectrophotometry
Correct Answer: Gel electrophoresis
Q22. What is the main function of a polyadenylation signal (poly-A signal) in an expression construct?
- Initiate DNA replication
- Terminate transcription and enhance mRNA stability and export
- Provide a translation start site
- Act as a selectable marker
Correct Answer: Terminate transcription and enhance mRNA stability and export
Q23. Which bioinformatic analysis is essential for identifying potential off-target sites for a designed CRISPR guide RNA?
- Protein docking simulation
- Genome-wide sequence alignment and off-target prediction algorithms
- Mass spectrometry data analysis
- Chromatogram peak integration
Correct Answer: Genome-wide sequence alignment and off-target prediction algorithms
Q24. In creating a transgenic mouse by pronuclear injection, what is typically injected into the fertilized egg?
- Purified protein only
- Linearized DNA construct containing the transgene
- siRNA against the gene
- Whole genomic DNA without promoter
Correct Answer: Linearized DNA construct containing the transgene
Q25. Which assay helps determine whether a transgenic promoter is tissue-specific in vivo?
- In vitro bacterial culture only
- Reporter gene assay (e.g., GFP or luciferase) in transgenic animal tissues
- Plasmid copy number measurement in bacteria
- Mass spectrometry of metabolites
Correct Answer: Reporter gene assay (e.g., GFP or luciferase) in transgenic animal tissues
Q26. What is the significance of using inducible promoters in transgenic studies?
- They make the transgene permanently silent
- They allow temporal control of gene expression to study phenotypes without developmental lethality
- They prevent transcription entirely
- They only function in prokaryotes
Correct Answer: They allow temporal control of gene expression to study phenotypes without developmental lethality
Q27. Which laboratory containment level is typically required for work with recombinant lentiviral vectors in research labs?
- Biosafety level 1 (BSL-1)
- Biosafety level 2 (BSL-2) with additional practices or BSL-2+ depending on vector modifications
- BSL-4 only
- No containment needed
Correct Answer: Biosafety level 2 (BSL-2) with additional practices or BSL-2+ depending on vector modifications
Q28. In comparative genomic hybridization (CGH), what is being compared to detect copy number variations?
- Protein sequences between species
- Labeled test genomic DNA versus reference genomic DNA hybridized to arrays or chips
- mRNA levels only
- Lipid profiles
Correct Answer: Labeled test genomic DNA versus reference genomic DNA hybridized to arrays or chips
Q29. Which term describes introduction of a foreign gene into plant genomes using Agrobacterium tumefaciens?
- Transduction
- Transformation via T-DNA mediated transfer
- Electroporation exclusively
- Conjugation between plants
Correct Answer: Transformation via T-DNA mediated transfer
Q30. When assessing transgenic product safety, which analysis is critical for ensuring therapeutic protein quality and consistency?
- Chromatographic and mass spectrometric characterization of protein structure, PTMs, and purity
- Only PCR to detect gene presence
- Visual inspection of cell cultures
- Measuring colony forming units
Correct Answer: Chromatographic and mass spectrometric characterization of protein structure, PTMs, and purity
