Introduction to plant biotechnology and applications in pharmacognosy MCQs With Answer

Introduction

Welcome to this focused MCQ set on “Introduction to Plant Biotechnology and Applications in Pharmacognosy” tailored for M.Pharm students. This collection reinforces core concepts linking plant tissue culture, genetic transformation, metabolic engineering and bioprocessing to the discovery, production and quality control of plant-derived pharmaceuticals. Questions emphasize practical applications such as micropropagation, hairy root and suspension cultures, elicitation, DNA-based authentication, cryopreservation and regulatory considerations. Designed for exam preparation and conceptual mastery, these items probe mechanisms, experimental choices and troubleshooting strategies commonly encountered in medicinal plant biotechnology and pharmacognosy research and development.

Q1. Which of the following best describes a primary application of plant biotechnology in pharmacognosy?

• Developing synthetic chemical analogs of plant compounds in a petrochemical facility
• Using tissue culture and genetic tools to enhance production and quality of plant-derived medicinal compounds
• Replacing all herbal medicines with synthetic small-molecule drugs
• Studying animal tissue response to botanical extracts without plant manipulation

Correct Answer: Using tissue culture and genetic tools to enhance production and quality of plant-derived medicinal compounds

Q2. Which micropropagation method generally minimizes somaclonal variation and maintains true-to-type clonal fidelity?

• Indirect organogenesis via long-term callus culture
• Prolonged suspension culture with repeated subculturing
• Direct organogenesis from nodal explants without an intervening callus phase
• Somatic embryogenesis from dedifferentiated callus over many cycles

Correct Answer: Direct organogenesis from nodal explants without an intervening callus phase

Q3. For the establishment of hairy root cultures that produce high levels of root-specific secondary metabolites, which bacterium is most commonly used to transform plant tissues?

• Agrobacterium tumefaciens
• Pseudomonas fluorescens
• Agrobacterium rhizogenes
• Rhizobium leguminosarum

Correct Answer: Agrobacterium rhizogenes

Q4. Which of the following is classified as an abiotic chemical elicitor commonly used to enhance secondary metabolite accumulation in plant cell cultures?

• Fungal cell wall fragments
• Salicylic acid produced by microbes
• Methyl jasmonate applied exogenously
• Live mycorrhizal inoculum

Correct Answer: Methyl jasmonate applied exogenously

Q5. What is a principal advantage of hairy root cultures over undifferentiated cell suspensions for production of certain plant secondary metabolites?

• Hairy roots require constant exogenous cytokinins for growth
• Hairy roots show genetic instability and variable metabolite profiles
• Hairy roots maintain organ-specific biosynthetic pathways and often produce higher yields in hormone-free media
• Hairy root cultures cannot be scaled up in bioreactors

Correct Answer: Hairy roots maintain organ-specific biosynthetic pathways and often produce higher yields in hormone-free media

Q6. Which technique is most appropriate when two sexually incompatible plant species must be combined to combine desirable biosynthetic traits?

• Marcottage
• Somatic hybridization by protoplast fusion
• Semi-dwarf breeding by backcrossing
• Classical cross-pollination

Correct Answer: Somatic hybridization by protoplast fusion

Q7. In the context of breeding medicinal plants, what is the main utility of marker-assisted selection (MAS)?

• It only sequences whole genomes without facilitating selection
• It identifies chemical constituents post-harvest
• It links molecular markers to desirable traits and accelerates selection in breeding programs
• It replaces the need for any phenotypic screening

Correct Answer: It links molecular markers to desirable traits and accelerates selection in breeding programs

Q8. Which pair of chloroplast loci is widely accepted as the core DNA barcode for land plants and useful for authentication of medicinal species?

• ITS2 and COI
• rbcL and matK
• 16S rRNA and nad5
• trnH-psbA and 18S rRNA

Correct Answer: rbcL and matK

Q9. To increase flux toward a target alkaloid in a transgenic plant cell line, which metabolic engineering strategy is most direct and often effective?

• Downregulate all upstream precursors to reduce competition
• Overexpress a rate‑limiting enzyme of the target biosynthetic pathway
• Eliminate all transporters to retain metabolites in vacuoles
• Introduce random mutagenesis without pathway knowledge

Correct Answer: Overexpress a rate‑limiting enzyme of the target biosynthetic pathway

Q10. Somaclonal variation is a concern in plant tissue culture. Which culture practice most increases the risk of somaclonal variation?

• Short-term direct organogenesis from axillary buds
• Prolonged maintenance of undifferentiated callus with many subcultures
• Using intact seeds for propagation
• Micrografting of shoot tips

Correct Answer: Prolonged maintenance of undifferentiated callus with many subcultures

Q11. Which cryopreservation technique functions primarily by preventing ice crystallization through formation of a vitrified glassy state?

• Slow programmable freezing with extracellular ice formation
• Encapsulation-dehydration with controlled sugar loading
• Vitrification using highly concentrated cryoprotectants
• Air-drying without cryoprotectants

Correct Answer: Vitrification using highly concentrated cryoprotectants

Q12. Which type of bioreactor design is generally most suitable for culturing hairy roots at scale while minimizing shear stress?

• High-speed stirred tank reactor with marine impellers
• Air-lift bioreactor or low-shear bubble column
• Rotating drum bioreactor operated at very high rpm
• Oscillating piston reactor with rapid mixing

Correct Answer: Air-lift bioreactor or low-shear bubble column

Q13. When applying CRISPR/Cas9 for targeted editing in medicinal plants, which approach best reduces off-target mutations?

• Using random single-guide RNAs without validation
• Delivering high concentrations of wild-type Cas9 protein only
• Employing high-fidelity Cas9 variants and carefully designed gRNAs
• Avoiding in silico off-target prediction and relying on phenotype screening

Correct Answer: Employing high-fidelity Cas9 variants and carefully designed gRNAs

Q14. Why do many plant cell suspension cultures produce lower yields of certain secondary metabolites compared to intact plants?

• Suspension cultures always have higher yields due to increased surface area
• Loss of tissue organization and compartmentalization disrupts pathway flux and storage
• Cell suspensions are permanently induced by pathogens to overproduce metabolites
• Suspension cultures are immune to elicitation strategies

Correct Answer: Loss of tissue organization and compartmentalization disrupts pathway flux and storage

Q15. For comprehensive structural identification and quantitation of multiple phytochemicals in a complex extract, which analytical technique provides the greatest sensitivity and structural information?

• Thin layer chromatography (TLC) without detectors
• High performance thin layer chromatography (HPTLC) visual inspection
• Liquid chromatography coupled with mass spectrometry (LC-MS)
• Colorimetric spot tests

Correct Answer: Liquid chromatography coupled with mass spectrometry (LC-MS)

Q16. Historically, which transformation method proved most effective for introducing foreign DNA into cereal monocots that are recalcitrant to Agrobacterium infection?

• Electroporation of whole seeds
• Biolistic (particle bombardment) transformation
• Agrobacterium-mediated floral dip
• Conjugation via E. coli

Correct Answer: Biolistic (particle bombardment) transformation

Q17. What role do endophytic microorganisms often play in the context of medicinal plant biotechnology?

• They always inhibit plant metabolite production
• They can biosynthesize host-like secondary metabolites and act as in situ elicitors or production platforms
• They are irrelevant to secondary metabolism and only affect root nitrogen fixation
• They replace the need for any plant biomass in phytopharmaceutical production

Correct Answer: They can biosynthesize host-like secondary metabolites and act as in situ elicitors or production platforms

Q18. Which auxin is most commonly used to induce somatic embryogenesis in many plant tissue culture systems?

• Indole-3-acetic acid (IAA) at trace levels only
• 2,4-Dichlorophenoxyacetic acid (2,4-D)
• Kinetin alone without auxin
• Gibberellic acid (GA3)

Correct Answer: 2,4-Dichlorophenoxyacetic acid (2,4-D)

Q19. For regulatory approval and quality control of a standardized phytopharmaceutical, which requirement is essential?

• Complete elimination of all natural variability regardless of processing
• Demonstration of batch‑to‑batch consistency through chemical standardization and stability testing
• Only traditional use documentation without chemical or biological testing
• Use of uncharacterized crude extracts with variable profiles

Correct Answer: Demonstration of batch‑to‑batch consistency through chemical standardization and stability testing

Q20. Which modern DNA-based approach allows detection and identification of multiple species within a complex multi-ingredient herbal formulation?

• Sanger sequencing of a single PCR amplicon without indexing
• DNA metabarcoding using high-throughput sequencing (NGS)
• Simple gel electrophoresis of genomic DNA
• Protein electrophoresis of crude extract

Correct Answer: DNA metabarcoding using high-throughput sequencing (NGS)

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