Micropropagation and micro-techniques for medicinal and aromatic plants MCQs With Answer

Introduction: Micropropagation and micro-techniques for medicinal and aromatic plants are essential components of Medicinal Plant Biotechnology for M.Pharm students. This blog-style quiz set focuses on practical and conceptual knowledge needed to efficiently culture, conserve and scale-up high-value medicinal species. You will review explant choice, sterilization, media formulation, plant growth regulators, organogenesis, somatic embryogenesis, synthetic seeds, cryopreservation, hairy root cultures, elicitation for secondary metabolites, and strategies to avoid contamination and somaclonal variation. These MCQs are designed to reinforce core principles, troubleshoot in vitro problems, and prepare you for laboratory applications and research in tissue culture of medicinal and aromatic plants.

Q1. Which explant is most commonly used for direct axillary shoot proliferation to maintain clonal fidelity in micropropagation of medicinal plants?

• Apical meristem
• Nodal segment
• Leaf disc
• Seed coat

Correct Answer: Nodal segment

Q2. Which surface sterilant is traditionally most effective at rapidly eliminating fungal spores and many bacteria on explants, though it requires careful handling?

• 70% Ethanol
• Sodium hypochlorite (bleach)
• Mercuric chloride (HgCl2)
• Hydrogen peroxide

Correct Answer: Mercuric chloride (HgCl2)

Q3. Which basal medium is most widely used as a starting point for tissue culture of medicinal plants due to its balanced macro- and micronutrients?

• Gamborg (B5) medium
• Murashige and Skoog (MS) medium
• Linsmaier & Skoog (LS) medium
• Nitsch medium

Correct Answer: Murashige and Skoog (MS) medium

Q4. Which plant growth regulator is most commonly used to induce and promote axillary shoot proliferation in medicinal plant micropropagation?

• Indole-3-acetic acid (IAA)
• 1-Naphthaleneacetic acid (NAA)
• 6-Benzylaminopurine (BAP)
• 2,4-Dichlorophenoxyacetic acid (2,4-D)

Correct Answer: 6-Benzylaminopurine (BAP)

Q5. Which auxin is considered most effective and widely used for induction of adventitious roots in micropropagated medicinal plants?

• Indole-3-acetic acid (IAA)
• Indole-3-butyric acid (IBA)
• 2,4-Dichlorophenoxyacetic acid (2,4-D)
• Gibberellic acid (GA3)

Correct Answer: Indole-3-butyric acid (IBA)

Q6. Which auxin is most frequently used to induce callus formation and initiate somatic embryogenesis in medicinal plant cultures?

• 6-Benzylaminopurine (BAP)
• 2,4-Dichlorophenoxyacetic acid (2,4-D)
• Indole-3-acetic acid (IAA)
• Kinetin

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

Q7. What is the most commonly used matrix for encapsulating somatic embryos to produce synthetic seeds for medicinal plants?

• Agar
• Sodium alginate
• Gelrite (gellan gum)
• Polyethylene glycol (PEG)

Correct Answer: Sodium alginate

Q8. Hairy root cultures used to produce secondary metabolites in many medicinal plants are induced by which bacterial factor?

• T-DNA from Agrobacterium tumefaciens
• rol genes from Agrobacterium rhizogenes
• Vir genes from Agrobacterium tumefaciens
• Phytoplasma plasmids

Correct Answer: rol genes from Agrobacterium rhizogenes

Q9. Which long-term conservation method stores plant germplasm at ultra-low temperatures to arrest metabolic activity of tissues or seeds?

• Slow growth storage at 4°C
• Vitrification and storage in liquid nitrogen (−196°C)
• Desiccation and storage at room temperature
• Short-term cold room storage at −20°C

Correct Answer: Vitrification and storage in liquid nitrogen (−196°C)

Q10. What is the primary cause of somaclonal variation observed in regenerated medicinal plants from long-term tissue cultures?

• Infection by endophytic microbes
• Genetic and epigenetic changes arising during in vitro culture
• Incorrect acclimatization procedures
• Natural phenotypic plasticity in greenhouse conditions

Correct Answer: Genetic and epigenetic changes arising during in vitro culture

Q11. Which bioreactor system is particularly suitable for scale-up of micropropagated shoots and temporary immersion culture to reduce hyperhydricity?

• Continuous stirred-tank bioreactor
• Temporary immersion bioreactor (e.g., RITA)
• Static flask culture
• Packed-bed soil-like bioreactor

Correct Answer: Temporary immersion bioreactor (e.g., RITA)

Q12. Which elicitor is widely used to enhance production of secondary metabolites (e.g., alkaloids, phenolics) in cell and hairy root cultures of medicinal plants?

• Sucrose
• Methyl jasmonate (MeJA)
• Benzyladenine (BAP)
• Auxin (IBA)

Correct Answer: Methyl jasmonate (MeJA)

Q13. Hyperhydricity (vitrification) in in vitro plantlets is commonly associated with which culture condition?

• Low cytokinin concentration
• High cytokinin concentration and excessive water availability
• High agar concentration
• Very low relative humidity in culture vessels

Correct Answer: High cytokinin concentration and excessive water availability

Q14. Micrografting in vitro is particularly useful for which practical purpose in medicinal plant micropropagation?

• Rescuing and providing root support for shoots with poor rooting ability
• Inducing high levels of somaclonal variation
• Directly inducing somatic embryogenesis
• Fusing protoplasts to produce hybrids

Correct Answer: Rescuing and providing root support for shoots with poor rooting ability

Q15. Protoplast fusion in plant biotechnology is primarily used to achieve which outcome relevant to medicinal plant improvement?

• Induction of apomixis
• Somatic hybridization between sexually incompatible species
• Elimination of viral infections
• Production of synthetic seed beads

Correct Answer: Somatic hybridization between sexually incompatible species

Q16. What is a major advantage of meristem-tip culture in propagation of medicinal plants?

• It produces plants with greater somaclonal variation
• It is an efficient method to obtain virus-free (clean) planting material
• It primarily enhances secondary metabolite synthesis
• It eliminates the need for acclimatization

Correct Answer: It is an efficient method to obtain virus-free (clean) planting material

Q17. Which carbon source is most commonly used in culture media for micropropagation and is preferred for uniform growth of medicinal plant tissues?

• Glucose
• Sucrose
• Fructose
• Sorbitol

Correct Answer: Sucrose

Q18. Which light quality generally promotes compact growth, increased chlorophyll formation and better acclimatization of in vitro shoots?

• Red light
• Blue light
• Far-red light
• Darkness

Correct Answer: Blue light

Q19. After alginate encapsulation of somatic embryos, which processing step is critical to producing storable synthetic seeds with improved storage and germination potential?

• Immediate sowing without further treatment
• Partial desiccation (controlled drying) of beads
• Soaking in high auxin solution
• Co-cultivation with Agrobacterium

Correct Answer: Partial desiccation (controlled drying) of beads

Q20. Slow growth storage of in vitro cultures to conserve medicinal germplasm for months typically involves which combination of conditions?

• High temperature (30–35°C) and continuous light
• Reduced temperature, low light and sometimes growth retardants
• High nutrient concentration and high sucrose
• Complete desiccation and storage at room temperature

Correct Answer: Reduced temperature, low light and sometimes growth retardants

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