Hybridization in medicinal plants combines classical breeding and modern biotechnology to develop hybrids with enhanced phytochemical content, disease resistance, and yield for pharmaceutical production. B. Pharm students should grasp controlled crosses, emasculation, cytoplasmic male sterility, heterosis (hybrid vigor), somatic hybridization (protoplast fusion), embryo rescue, and polyploidy, plus evaluation tools like marker-assisted selection, chemotyping, SSR/SNP markers, and flow cytometry. Understanding F1 uniformity, segregation in F2, backcross strategies, and trait fixation is essential for improving alkaloid, terpene, and phenolic profiles. This knowledge links plant genetics to drug quality, cultivation, and conservation of medicinal species. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the classical definition of hybridization in medicinal plant breeding?
- Crossing two genetically identical individuals
- Crossing two genetically different parents to produce offspring
- Inducing mutations using chemicals
- Cloning a superior plant via tissue culture
Correct Answer: Crossing two genetically different parents to produce offspring
Q2. What does heterosis (hybrid vigor) most commonly describe?
- Reduced fertility in hybrids
- Superior performance of F1 hybrids compared to parents
- Appearance of new diseases in hybrids
- Loss of phytochemical production in hybrids
Correct Answer: Superior performance of F1 hybrids compared to parents
Q3. Which technique is essential for making a controlled cross in flowering medicinal plants?
- Seed stratification
- Emasculation followed by controlled pollination
- Leaf grafting
- Protoplast isolation
Correct Answer: Emasculation followed by controlled pollination
Q4. Somatic hybridization in medicinal plants is achieved by which method?
- Cross-pollination under isolation
- Protoplast fusion and regeneration
- Backcrossing to the recurrent parent
- Selection from F2 segregating populations
Correct Answer: Protoplast fusion and regeneration
Q5. Cytoplasmic male sterility (CMS) is useful in hybrid seed production because it:
- Prevents all types of cross-pollination
- Masks desirable phytochemical traits
- Abolishes need for emasculation by causing male sterility
- Causes permanent sterility in both sexes
Correct Answer: Abolishes need for emasculation by causing male sterility
Q6. Which statement correctly contrasts F1 and F2 generations?
- F1 shows maximum segregation; F2 is uniform
- F1 is genetically uniform; F2 shows segregation of traits
- Both F1 and F2 are genetically identical to parents
- F1 is sterile while F2 always fertile
Correct Answer: F1 is genetically uniform; F2 shows segregation of traits
Q7. Backcrossing in medicinal plant breeding is primarily used to:
- Create F1 hybrids only
- Introduce a specific trait from a donor into an elite parent
- Increase polyploidy levels
- Induce somaclonal variation
Correct Answer: Introduce a specific trait from a donor into an elite parent
Q8. The main advantage of marker-assisted selection (MAS) in hybridization is:
- Reduced need for field trials entirely
- Faster and more precise selection for target genes
- Guaranteed expression of polygenic traits
- Replacement of chemical analysis for phytochemicals
Correct Answer: Faster and more precise selection for target genes
Q9. Protoplast fusion helps breeders overcome which limitation?
- Low seed viability in selfing species
- Sexual incompatibility between distantly related species
- Environmental stress during field trials
- Poor marker reproducibility
Correct Answer: Sexual incompatibility between distantly related species
Q10. Embryo rescue is a technique used when:
- Hybrid embryos abort before seed maturation
- Seeds are too large to handle
- Hybrid plants are polyploid
- F1 hybrids show heterosis
Correct Answer: Hybrid embryos abort before seed maturation
Q11. Allogamy in plant reproduction refers to:
- Self-fertilization within the same flower
- Cross-fertilization between different individuals
- Asexual reproduction via runners
- Genome doubling to create autopolyploids
Correct Answer: Cross-fertilization between different individuals
Q12. Self-incompatibility mechanisms in medicinal plants function to:
- Promote selfing and reduce diversity
- Prevent self-fertilization and encourage outcrossing
- Increase mutation rates in pollen
- Enhance seed dormancy
Correct Answer: Prevent self-fertilization and encourage outcrossing
Q13. Polyploidization of a medicinal plant commonly results in:
- Loss of all secondary metabolites
- Increase in chromosome number and often larger cell/organ size
- Immediate sterility in F1 hybrids only
- Elimination of heterosis
Correct Answer: Increase in chromosome number and often larger cell/organ size
Q14. Which molecular marker type is co-dominant, highly reproducible, and useful for hybrid identification?
- RAPD
- AFLP
- SSR (microsatellites)
- Random chemical spots
Correct Answer: SSR (microsatellites)
Q15. Random Amplified Polymorphic DNA (RAPD) markers are characterized by:
- High reproducibility and co-dominance
- Dominant inheritance and lower reproducibility
- Use only for metabolite analysis
- Being identical to SSR markers
Correct Answer: Dominant inheritance and lower reproducibility
Q16. Flow cytometry in breeding programs is most commonly used to:
- Measure soil nutrient status
- Estimate nuclear DNA content and ploidy level
- Profile alkaloid composition
- Assess pollen viability visually
Correct Answer: Estimate nuclear DNA content and ploidy level
Q17. Heterobeltiosis describes:
- F1 performance inferior to both parents
- F1 superior to the better parent
- Segregation in F2 generation
- Complete sterility in hybrids
Correct Answer: F1 superior to the better parent
Q18. Hybrid breakdown refers to:
- Improved vigor in successive generations
- Reduced fitness or fertility in later hybrid generations
- Immediate sterility of F1 only
- Enhanced alkaloid production in F2
Correct Answer: Reduced fitness or fertility in later hybrid generations
Q19. Chemotyping in medicinal plant improvement means:
- Genotyping only with SSR markers
- Chemical profiling to classify plants based on metabolite composition
- Measuring photosynthetic rate
- Counting chromosome numbers
Correct Answer: Chemical profiling to classify plants based on metabolite composition
Q20. A primary pharmaceutical aim of hybridization in medicinal plants is to:
- Reduce all secondary metabolites
- Improve yield and consistency of target phytochemicals (e.g., alkaloids)
- Ensure plants never flower
- Remove all genetic diversity
Correct Answer: Improve yield and consistency of target phytochemicals (e.g., alkaloids)
Q21. Emasculation in hybridization procedure refers to:
- Removing the stigma to prevent pollination
- Removing anthers to prevent self-pollination
- Applying growth regulators to induce flowering
- Bagging whole plants without any manipulation
Correct Answer: Removing anthers to prevent self-pollination
Q22. Cytoplasmic male sterility (CMS) is usually inherited via:
- Nuclear genes with Mendelian segregation
- Maternal inheritance through mitochondrial or plastid genomes
- Pollen-borne paternal inheritance only
- Random environmental changes
Correct Answer: Maternal inheritance through mitochondrial or plastid genomes
Q23. A key difference between somatic hybrids and sexual hybrids is that somatic hybrids:
- Require pollen to combine genomes
- Are produced by fusion of somatic cells and can combine genomes irrespective of sexual compatibility
- Always produce fertile progeny
- Cannot be regenerated into whole plants
Correct Answer: Are produced by fusion of somatic cells and can combine genomes irrespective of sexual compatibility
Q24. General combining ability (GCA) in hybrid breeding primarily reflects:
- Non-additive gene effects only
- Additive gene effects and average performance of a parent in hybrids
- Environmental variance unrelated to genetics
- Only cytoplasmic inheritance
Correct Answer: Additive gene effects and average performance of a parent in hybrids
Q25. Which breeding method tracks pedigree and selection across generations for complex traits?
- Mass selection without records
- Pedigree selection method
- Random mutagenesis
- Clonal propagation only
Correct Answer: Pedigree selection method
Q26. To evaluate hybrid performance for medicinal use, breeders should conduct:
- Single-plant greenhouse trials only
- Multi-location field trials including chemotype analysis
- Only laboratory DNA tests without field data
- Trials in one location every ten years
Correct Answer: Multi-location field trials including chemotype analysis
Q27. Which agent is commonly used for in vitro chromosome doubling (polyploidization)?
- Ribonuclease
- Colchicine
- Auxin only
- Kanamycin
Correct Answer: Colchicine
Q28. A common breeding challenge unique to medicinal plant hybridization is:
- Unlimited funding for trials
- Segregation and instability of target phytochemical traits in progeny
- Complete absence of natural variation
- Easy fixation of multi-gene traits in F1
Correct Answer: Segregation and instability of target phytochemical traits in progeny
Q29. Restoration of fertility in CMS hybrids is governed by:
- Only mitochondrial genes
- Nuclear restorer genes (Rf) that interact with cytoplasmic factors
- Random environmental factors exclusively
- Chloroplast DNA changes only
Correct Answer: Nuclear restorer genes (Rf) that interact with cytoplasmic factors
Q30. For high-resolution mapping of quantitative trait loci (QTL) for alkaloid content, which marker type is most suitable?
- Morphological markers only
- SNP markers due to high density and genome coverage
- Random colorimetry spots
- RFLP markers only, ignoring SNPs
Correct Answer: SNP markers due to high density and genome coverage
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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