Cloning strategies, plant cell cloning and advantages/disadvantages MCQs With Answer

Introduction: Cloning strategies, plant cell cloning and advantages/disadvantages MCQs With Answer offers M.Pharm students a focused revision tool on contemporary cloning methods applied to medicinal plants. This set covers micropropagation, somatic embryogenesis, organogenesis, protoplast fusion, synthetic seeds, and bioreactor scale-up with emphasis on protocol variables, genetic fidelity, and practical constraints. Questions probe hormonal control, explant selection, sterility, somaclonal variation, and downstream advantages such as uniform secondary metabolite production and conservation, as well as disadvantages like genotype dependency and high cost. The quiz is designed to deepen conceptual understanding, prepare for exams, and link lab practice to therapeutic plant biotechnology.

Q1. Which of the following best defines somatic embryogenesis in plant cell cloning?

• Development of embryos from gametes after fertilization
• Formation of embryo-like structures from somatic (non-reproductive) cells
• Re-differentiation of root tissue into leaves directly
• Fusion of protoplasts to create hybrid embryos

Correct Answer: Formation of embryo-like structures from somatic (non-reproductive) cells

Q2. In micropropagation, which stage primarily involves multiplication of shoots from an explant?

• Initiation stage
• Elongation stage
• Multiplication stage
• Acclimatization stage

Correct Answer: Multiplication stage

Q3. Which phytohormone combination is commonly used to induce organogenesis (shoot formation) in many medicinal plants?

• High auxin : low cytokinin
• Equal auxin and gibberellin
• High cytokinin : low auxin
• High abscisic acid : low cytokinin

Correct Answer: High cytokinin : low auxin

Q4. What is somaclonal variation and why is it a concern in plant cell cloning for medicinal plants?

• Variation among seeds due to cross-pollination; it increases yield
• Genetic variability arising during tissue culture; it can alter secondary metabolite profiles
• Environmental variation in field-grown clones; it has no impact on medicine
• Temporary physiological changes induced by light; easily reversible

Correct Answer: Genetic variability arising during tissue culture; it can alter secondary metabolite profiles

Q5. Which explant source is generally preferred for preserving genetic fidelity during micropropagation?

• Callus-derived regenerants
• Axillary buds or nodal segments
• Etiolated hypocotyl segments
• Protoplast-derived cell lines

Correct Answer: Axillary buds or nodal segments

Q6. Protoplast fusion is most useful in cloning strategies when the goal is to:

• Produce identical clones of the mother plant without variation
• Combine genomes of sexually incompatible species to create somatic hybrids
• Generate seeds via somatic embryogenesis
• Sterilize explants more effectively

Correct Answer: Combine genomes of sexually incompatible species to create somatic hybrids

Q7. Which culture medium is most widely used as a basal medium for plant tissue culture and cloning?

• Nutrient Agar (NA)
• Luria-Bertani (LB) medium
• Murashige and Skoog (MS) medium
• Potato Dextrose Agar (PDA)

Correct Answer: Murashige and Skoog (MS) medium

Q8. Synthetic seeds are most commonly produced by encapsulating which propagule?

• Whole plants in alginate beads
• Somatic embryos or microshoots in hydrogel beads
• Leaf discs with auxin pellets
• Protoplasts in agar plugs

Correct Answer: Somatic embryos or microshoots in hydrogel beads

Q9. Which of the following is a major advantage of plant cell cloning for medicinal plant production?

• Guaranteed elimination of all pathogens in regenerated plants
• Uniform production of plants with consistent secondary metabolite profiles
• No requirement for sterile techniques
• Insensitivity to genotype effects

Correct Answer: Uniform production of plants with consistent secondary metabolite profiles

Q10. Which technique is commonly used to assess genetic fidelity of clones produced by tissue culture?

• High-performance liquid chromatography (HPLC) only
• Random Amplified Polymorphic DNA (RAPD) or SSR marker analysis
• Light microscopy of leaf anatomy
• Soil nutrient analysis

Correct Answer: Random Amplified Polymorphic DNA (RAPD) or SSR marker analysis

Q11. What is a primary disadvantage of large-scale micropropagation in the context of medicinal plant biotechnology?

• It always produces genetically unstable plants
• High establishment and operational costs for sterile infrastructure
• It eliminates the need for downstream processing
• It cannot produce disease-free plants

Correct Answer: High establishment and operational costs for sterile infrastructure

Q12. Temporary immersion bioreactors (TIBs) are used in plant cloning primarily to:

• Provide continuous liquid aeration without immersion
• Reduce hyperhydricity and improve nutrient/gas exchange during scale-up
• Replace growth regulators completely
• Solidify the medium for easier handling

Correct Answer: Reduce hyperhydricity and improve nutrient/gas exchange during scale-up

Q13. Which sterilizing agent is commonly used for surface sterilization of explants prior to culture?

• Sodium hypochlorite (bleach)
• Sodium dodecyl sulfate (SDS)
• Absolute ethanol (100%) only
• Chloramphenicol

Correct Answer: Sodium hypochlorite (bleach)

Q14. Encapsulation-dehydration followed by cryopreservation is advantageous because it:

• Increases somaclonal variation for new traits
• Allows long-term storage of clonal germplasm with high survival after thawing
• Eliminates the need for explant sterilization
• Is the cheapest method for in situ conservation

Correct Answer: Allows long-term storage of clonal germplasm with high survival after thawing

Q15. Which factor most strongly influences the success of somatic embryogenesis in medicinal plants?

• Light color only
• Combination and concentration of plant growth regulators, especially auxins and cytokinins
• Type of soil used post-acclimatization
• Ambient sound levels in the culture room

Correct Answer: Combination and concentration of plant growth regulators, especially auxins and cytokinins

Q16. Micrografting in medicinal plants is applied mainly to:

• Fuse protoplasts of two species
• Rescue or recover elite clones by grafting a microshoot onto an in vitro rootstock
• Sterilize explants mechanically
• Transform plants with Agrobacterium

Correct Answer: Rescue or recover elite clones by grafting a microshoot onto an in vitro rootstock

Q17. Which of the following is a biochemical disadvantage associated with somaclonal variation in medicinal plant clones?

• Improved aroma consistency
• Altered secondary metabolite profiles compromising therapeutic efficacy
• Complete immunity to pathogens
• Guaranteed higher yield of active compounds

Correct Answer: Altered secondary metabolite profiles compromising therapeutic efficacy

Q18. In protoplast culture, what is PEG (polyethylene glycol) commonly used for?

• As a gelling agent to solidify medium
• To facilitate protoplast fusion by inducing membrane fusion
• To act as a carbon source replacing sucrose
• To sterilize the culture vessel

Correct Answer: To facilitate protoplast fusion by inducing membrane fusion

Q19. Which statement correctly contrasts organogenesis and somatic embryogenesis?

• Organogenesis forms whole plants via embryo-like structures; somatic embryogenesis forms shoots only
• Organogenesis regenerates organs (shoots/roots) often via callus; somatic embryogenesis produces bipolar embryo-like structures capable of whole-plant regeneration
• Both processes always require zygotic embryos as starting material
• Organogenesis is exclusively performed in liquid cultures, somatic embryogenesis on solid media

Correct Answer: Organogenesis regenerates organs (shoots/roots) often via callus; somatic embryogenesis produces bipolar embryo-like structures capable of whole-plant regeneration

Q20. For quality control of clonally propagated medicinal plants intended for pharmaceutical use, which combined approach is most appropriate?

• Visual inspection only
• Molecular marker analysis for genetic fidelity plus chemical profiling of active constituents (e.g., HPLC)
• Soil fertility tests after acclimatization only
• Counting number of leaves per plant as a sole parameter

Correct Answer: Molecular marker analysis for genetic fidelity plus chemical profiling of active constituents (e.g., HPLC)

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