Mutation in medicinal plants MCQs With Answer

Mutation in medicinal plants MCQs With Answer

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Introduction: Mutation in medicinal plants explores induced genetic changes to improve yield, stability, and concentration of pharmacologically active secondary metabolites. For B.Pharm students, understanding mutagenesis—physical (radiation), chemical (EMS, MNNG), and molecular approaches (TILLING, CRISPR-assisted mutation)—is essential for pharmaceutical plant improvement, phytochemical enhancement, and quality control. Topics include mutation types (point, insertion, deletion, chromosomal), screening methods (biochemical assays, molecular markers, cytogenetics), dose–response and LD50 considerations, biosafety and regulatory aspects, and the role of mutation breeding in drug development. This knowledge links plant genetics with drug discovery, formulation consistency, and therapeutic efficacy. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the primary goal of induced mutation breeding in medicinal plants?

  • To create ornamental plant varieties
  • To increase genetic variability for improved secondary metabolite production
  • To eliminate all natural variation in a population
  • To develop herbicide-resistant weeds

Correct Answer: To increase genetic variability for improved secondary metabolite production

Q2. Which of the following is a commonly used chemical mutagen in plant mutation studies?

  • Gamma rays
  • Ethyl methanesulfonate (EMS)
  • CRISPR-Cas9
  • Ultraviolet B light

Correct Answer: Ethyl methanesulfonate (EMS)

Q3. Which physical mutagen is most effective for causing chromosomal breaks in seeds and tissues?

  • Ethyl methanesulfonate (EMS)
  • Gamma radiation
  • Base analogs
  • Agrobacterium transformation

Correct Answer: Gamma radiation

Q4. TILLING is a reverse genetics tool primarily used to:

  • Induce polyploidy with colchicine
  • Screen for induced point mutations in specific genes
  • Insert transgenes into chloroplast genomes
  • Create random chromosomal rearrangements

Correct Answer: Screen for induced point mutations in specific genes

Q5. Which molecular marker technique is useful for detecting single nucleotide polymorphisms (SNPs) created by mutagenesis?

  • RAPD
  • AFLP
  • SSR (microsatellites)
  • SNP genotyping or sequencing

Correct Answer: SNP genotyping or sequencing

Q6. Which repair mechanism primarily fixes UV-induced thymine dimers in plant DNA?

  • Base excision repair
  • Nucleotide excision repair
  • Homologous recombination
  • Non-homologous end joining

Correct Answer: Nucleotide excision repair

Q7. Somaclonal variation refers to:

  • Variation induced by chemical mutagens only
  • Genetic variation arising during plant tissue culture
  • A targeted gene editing technique
  • Stable transgene expression in regenerants

Correct Answer: Genetic variation arising during plant tissue culture

Q8. Which of the following is a key consideration when choosing mutagen dose in mutation breeding?

  • Maximize lethality to eliminate weak genotypes
  • Use the highest possible dose to ensure mutations
  • Balance between mutation frequency and plant survival (LD50 principles)
  • Avoid any measurable physiological effect

Correct Answer: Balance between mutation frequency and plant survival (LD50 principles)

Q9. A point mutation that changes an amino acid codon to a stop codon is called:

  • Missense mutation
  • Nonsense mutation
  • Silent mutation
  • Frameshift mutation

Correct Answer: Nonsense mutation

Q10. Which cytogenetic technique is commonly used to detect large chromosomal rearrangements in mutated plants?

  • HPLC analysis
  • Fluorescence in situ hybridization (FISH)
  • Mass spectrometry
  • ELISA

Correct Answer: Fluorescence in situ hybridization (FISH)

Q11. Which phrase best describes forward genetic screening in mutation studies?

  • Mutating a specific gene and checking phenotype
  • Identifying mutants by phenotype and then mapping the gene
  • Directly sequencing genomes of mutants without phenotyping
  • Using only molecular markers to predict traits

Correct Answer: Identifying mutants by phenotype and then mapping the gene

Q12. Which biochemical method is most appropriate for screening mutants with altered alkaloid content?

  • Chromatography (HPLC/GC-MS)
  • PCR amplification
  • Southern blotting
  • Flow cytometry

Correct Answer: Chromatography (HPLC/GC-MS)

Q13. Polyploidy induction in medicinal plants is often used to:

  • Reduce secondary metabolite production
  • Increase cell size and sometimes enhance metabolite yield
  • Precisely edit single nucleotides
  • Eliminate all genetic variability

Correct Answer: Increase cell size and sometimes enhance metabolite yield

Q14. Which of the following is a disadvantage of random chemical mutagenesis?

  • It produces targeted, single-base changes only
  • Generation of many off-target mutations requiring extensive screening
  • It cannot induce point mutations
  • It always leads to sterile plants

Correct Answer: Generation of many off-target mutations requiring extensive screening

Q15. In mutation breeding, the M1 generation typically refers to:

  • The original wild-type population
  • The first generation grown directly from treated seed or explant
  • The stabilized, homozygous mutants after selection
  • A generation derived by tissue culture only

Correct Answer: The first generation grown directly from treated seed or explant

Q16. Which technique combines induced mutations with high-throughput screening to identify allelic variants in target genes?

  • TILLING
  • RAPD analysis
  • Chromosomal painting
  • Protein electrophoresis

Correct Answer: TILLING

Q17. Mutations in chloroplast genes are typically inherited how in most plants?

  • Maternally or uniparentally in many species
  • Strictly biparentally
  • Only via pollen in all plants
  • Not inherited at all

Correct Answer: Maternally or uniparentally in many species

Q18. Which assay would you use to assess genotoxicity of a chemical mutagen on plant cells?

  • Comet assay (single-cell gel electrophoresis)
  • LC-MS quantification of alkaloids
  • Western blot for secondary metabolite enzymes
  • ELISA for phytohormones

Correct Answer: Comet assay (single-cell gel electrophoresis)

Q19. Marker-assisted selection (MAS) in mutation breeding is valuable because it:

  • Eliminates the need for phenotypic screening entirely
  • Allows early selection of desirable alleles linked to traits
  • Only works for transgenic plants
  • Is insensitive to background genetic variation

Correct Answer: Allows early selection of desirable alleles linked to traits

Q20. Which induced mutation type is most likely to cause a frameshift?

  • Single base substitution
  • Insertion or deletion of bases not in multiples of three
  • Large chromosomal duplication
  • Point mutation that is silent

Correct Answer: Insertion or deletion of bases not in multiples of three

Q21. Which factor most influences the spectrum of mutations produced by a mutagen?

  • Plant height
  • Type and mode of action of the mutagen
  • Soil pH only
  • Time of day when harvesting seeds

Correct Answer: Type and mode of action of the mutagen

Q22. A stable mutant line suitable for pharmaceutical use must be:

  • Highly variable across generations
  • Genetically and phenotypically stable with consistent compound yield
  • Only tested in the M1 generation
  • Cryptic and uncharacterized

Correct Answer: Genetically and phenotypically stable with consistent compound yield

Q23. Which molecular tool can precisely introduce targeted mutations, complementing traditional mutagenesis?

  • EMS treatment
  • CRISPR-Cas systems
  • Gamma irradiation
  • UV light exposure

Correct Answer: CRISPR-Cas systems

Q24. What is a common first step when screening mutagenized populations for altered secondary metabolite profiles?

  • Whole-genome sequencing of every plant
  • Preliminary biochemical screening such as thin-layer chromatography or HPLC
  • Fluorescence in situ hybridization
  • ELISA for DNA damage

Correct Answer: Preliminary biochemical screening such as thin-layer chromatography or HPLC

Q25. Which outcome indicates a successful gain-of-function mutation affecting biosynthesis of a therapeutic compound?

  • Reduced or absent target metabolite
  • Increased accumulation or new biosynthetic activity producing the therapeutic compound
  • Sterility with no metabolite change
  • Only morphological changes with no biochemical effect

Correct Answer: Increased accumulation or new biosynthetic activity producing the therapeutic compound

Q26. In context of regulatory safety for herbal drugs derived from mutants, which aspect is critical?

  • Only the mutation method used
  • Characterization of phytochemical profile, toxicity testing, and stability
  • Keeping the breeding records private
  • Using the highest mutagen dose possible

Correct Answer: Characterization of phytochemical profile, toxicity testing, and stability

Q27. Which analytical approach helps link genotype changes from mutagenesis to altered metabolic pathways?

  • Metabolomics combined with genomics and transcriptomics
  • Simple morphological observation only
  • Classical Mendelian ratio analysis only
  • Routine soil nutrient assays

Correct Answer: Metabolomics combined with genomics and transcriptomics

Q28. Which is TRUE about mutation frequency in relation to mutagen dose?

  • Mutation frequency always decreases with dose
  • Mutation frequency typically increases with dose up to a point but may be offset by lethality
  • Dose has no effect on mutation frequency
  • Lower doses always produce the highest number of useful mutants

Correct Answer: Mutation frequency typically increases with dose up to a point but may be offset by lethality

Q29. Which of the following best describes a selectable marker in mutation breeding?

  • A biochemical assay that identifies plants with desired metabolite changes
  • A physical device used in irradiation
  • Non-specific DNA damage
  • Asoil amendment to increase growth

Correct Answer: A biochemical assay that identifies plants with desired metabolite changes

Q30. Why is backcrossing often used after obtaining a desirable mutant in medicinal plant breeding?

  • To introduce additional random mutations
  • To transfer the desired mutation into elite genetic backgrounds while removing unwanted mutations
  • To increase genetic heterogeneity permanently
  • Backcrossing is unnecessary and rarely used

Correct Answer: To transfer the desired mutation into elite genetic backgrounds while removing unwanted mutations

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