Q.1 What is the primary purpose of using Agrobacterium tumefaciens in plant genetic engineering?
To increase soil nitrogen content
To transfer DNA into plant cells
To act as a pesticide
To enhance photosynthetic efficiency
Explanation - Agrobacterium tumefaciens naturally transfers a segment of its DNA (T‑DNA) into the genome of infected plants, a mechanism exploited to introduce desired genes.
Correct answer is: To transfer DNA into plant cells
Q.2 Which of the following is a common selectable marker used in plant transformation?
Green fluorescent protein (GFP)
Beta‑glucuronidase (GUS)
Kanamycin resistance (nptII)
Luciferase (LUC)
Explanation - Kanamycin resistance allows transformed cells to survive on media containing the antibiotic, facilitating selection of successful transformants.
Correct answer is: Kanamycin resistance (nptII)
Q.3 CRISPR/Cas9 creates double‑strand breaks at specific genomic locations. What cellular mechanism primarily repairs these breaks in plants?
Base excision repair
Non‑homologous end joining (NHEJ)
Mismatch repair
Photoreactivation
Explanation - NHEJ ligates broken DNA ends without a template, often resulting in insertions or deletions that can knock out gene function.
Correct answer is: Non‑homologous end joining (NHEJ)
Q.4 Which trait was first introduced into a commercial crop using genetic engineering?
Herbicide tolerance in soybeans
Insect resistance in Bt cotton
Virus resistance in papaya
Drought tolerance in maize
Explanation - The first commercial GM crop, Roundup Ready soybean (1996), was engineered for tolerance to glyphosate herbicide.
Correct answer is: Herbicide tolerance in soybeans
Q.5 RNA interference (RNAi) in plants is primarily used to:
Increase chlorophyll content
Silence specific genes
Enhance root growth
Promote fruit ripening
Explanation - RNAi triggers degradation of target mRNA, effectively reducing expression of the corresponding gene.
Correct answer is: Silence specific genes
Q.6 What is the main advantage of using a tissue‑specific promoter in a transgenic plant?
It drives expression in all plant parts equally
It restricts transgene expression to desired tissues
It increases overall plant growth rate
It eliminates the need for selectable markers
Explanation - Tissue‑specific promoters limit expression to certain organs (e.g., seed‑specific), reducing potential side effects elsewhere.
Correct answer is: It restricts transgene expression to desired tissues
Q.7 Which of the following crops was saved from the ringspot virus by genetic engineering?
Papaya
Banana
Wheat
Rice
Explanation - Transgenic papaya expressing the coat protein gene of Papaya ringspot virus provided resistance and saved Hawaiian papaya production.
Correct answer is: Papaya
Q.8 In plant breeding, what does the term ‘heterosis’ refer to?
Hybrid vigor
Genetic drift
Inbreeding depression
Polyploidy
Explanation - Heterosis is the phenomenon where hybrid offspring outperform their parents in traits like yield, growth, or resistance.
Correct answer is: Hybrid vigor
Q.9 Which technique is used to double the chromosome number in plants to create polyploids?
Colchicine treatment
Agrobacterium infection
Electroporation
Somatic embryogenesis
Explanation - Colchicine disrupts spindle formation during cell division, leading to chromosome duplication and polyploidy.
Correct answer is: Colchicine treatment
Q.10 What is a ‘gene stack’ in the context of GMO crops?
A single gene with multiple functions
Multiple genes inserted into separate loci
Several transgenes combined in one construct
A gene with a stacked promoter
Explanation - Gene stacking refers to integrating multiple traits (e.g., herbicide tolerance and insect resistance) within a single plant line.
Correct answer is: Several transgenes combined in one construct
Q.11 Which of the following is NOT a method for delivering DNA into plant cells?
Particle bombardment (biolistics)
Electroporation
Microinjection
Sonication
Explanation - Sonication is used to fragment DNA, not to introduce it into cells. The other three are established plant transformation methods.
Correct answer is: Sonication
Q.12 What is the main role of the CaMV 35S promoter in plant biotechnology?
To confer virus resistance
To drive strong, constitutive expression of a transgene
To act as a selectable marker
To silence endogenous genes
Explanation - The cauliflower mosaic virus 35S promoter is widely used because it works in many plant species and tissues.
Correct answer is: To drive strong, constitutive expression of a transgene
Q.13 Which type of DNA repair can be harnessed for precise gene editing using a donor template?
Non‑homologous end joining (NHEJ)
Microhomology‑mediated end joining (MMEJ)
Homology‑directed repair (HDR)
Base excision repair (BER)
Explanation - HDR uses a homologous DNA template to accurately repair a break, allowing precise insertion or replacement of sequences.
Correct answer is: Homology‑directed repair (HDR)
Q.14 What is the purpose of using a reporter gene such as GUS in plant transformation experiments?
To confer disease resistance
To select transformed cells on antibiotic media
To visually confirm transgene expression
To increase photosynthetic rate
Explanation - The GUS enzyme produces a blue color when its substrate is present, indicating where the transgene is active.
Correct answer is: To visually confirm transgene expression
Q.15 In the context of plant tissue culture, what does ‘somatic embryogenesis’ refer to?
Formation of embryos from gametes
Development of embryos from somatic (non‑reproductive) cells
Regeneration of plants from root tips
Induction of flower buds in vitro
Explanation - Somatic embryogenesis allows mass propagation and genetic manipulation without sexual reproduction.
Correct answer is: Development of embryos from somatic (non‑reproductive) cells
Q.16 Which crop has been engineered to produce high‑oleic acid oil to improve nutritional quality?
Canola
Barley
Soybean
Sorghum
Explanation - High‑oleic acid canola varieties have been created by down‑regulating the FAD2 gene, yielding oil with better health properties.
Correct answer is: Canola
Q.17 What is the primary reason for developing drought‑tolerant transgenic crops?
To increase seed size
To reduce water usage in agriculture
To enhance flavor
To make plants herbicide‑resistant
Explanation - Drought‑tolerant crops maintain yields under limited water, conserving resources and improving food security.
Correct answer is: To reduce water usage in agriculture
Q.18 Which of the following is a common method to confirm the presence of a transgene in a plant?
Western blotting
Polymerase chain reaction (PCR)
Gas chromatography
Spectrophotometry
Explanation - PCR amplifies specific DNA sequences, allowing detection of the transgene’s presence in genomic DNA.
Correct answer is: Polymerase chain reaction (PCR)
Q.19 What does the term ‘cisgenesis’ describe?
Transfer of genes between unrelated species
Insertion of genes from the same species or a crossable relative
Use of synthetic DNA constructs only
Editing of genes without any DNA insertion
Explanation - Cisgenesis avoids foreign DNA, using only genetic material that could be transferred through conventional breeding.
Correct answer is: Insertion of genes from the same species or a crossable relative
Q.20 Which plant hormone is commonly used to induce callus formation in tissue culture?
Auxin
Cytokinin
Gibberellin
Abscisic acid
Explanation - High auxin to cytokinin ratios promote dedifferentiation of cells into a proliferative callus.
Correct answer is: Auxin
Q.21 In the context of biosafety, what does the term ‘gene flow’ refer to?
Transfer of genes from a GM crop to wild relatives
Movement of genes within a single plant cell
Exchange of DNA between mitochondria and nucleus
Horizontal gene transfer between bacteria only
Explanation - Gene flow can occur via pollen or seed dispersal, raising ecological and regulatory concerns.
Correct answer is: Transfer of genes from a GM crop to wild relatives
Q.22 Which of the following is a major advantage of using marker‑free transformation systems?
Faster plant growth
Elimination of antibiotic resistance genes from the final product
Increased seed yield
Higher resistance to pests
Explanation - Marker‑free methods avoid public and regulatory concerns associated with antibiotic or herbicide resistance markers.
Correct answer is: Elimination of antibiotic resistance genes from the final product
Q.23 What is the main function of the enzyme ACC synthase in plants?
Biosynthesis of ethylene
Degradation of chlorophyll
Synthesis of starch
Transport of sugars
Explanation - ACC synthase converts S‑adenosyl‑methionine to ACC, the immediate precursor of ethylene, a hormone involved in fruit ripening.
Correct answer is: Biosynthesis of ethylene
Q.24 Which of the following is a primary method for creating a transgenic plant without using a bacterial vector?
Electroporation of protoplasts
Agrobacterium-mediated transformation
Particle bombardment
Micropropagation
Explanation - Biolistics uses high‑velocity gold or tungsten particles coated with DNA to deliver genes directly into plant cells.
Correct answer is: Particle bombardment
Q.25 In crop improvement, what does the term ‘QTL’ stand for?
Quantitative Trait Locus
Quick Transfer Line
Quality Trait List
Quantum Transgenic Locus
Explanation - QTLs are genomic regions associated with variation in quantitative traits like yield or drought tolerance.
Correct answer is: Quantitative Trait Locus
Q.26 Which of the following crops was the first to receive a gene editing (CRISPR) based commercial approval?
Tomato
Soybean
Mushroom
Wheat
Explanation - In 2016, the U.S. FDA approved a CRISPR‑edited mushroom with reduced browning, marking the first commercial gene‑edited food.
Correct answer is: Mushroom
Q.27 What does the term ‘transgene escape’ describe in agricultural biotechnology?
Loss of transgene expression over generations
Transfer of the transgene to non‑target species
Mutation of the transgene within the host plant
Deletion of the transgene during seed storage
Explanation - Transgene escape concerns the spread of engineered genes to wild relatives or other crops via pollen or seed dispersal.
Correct answer is: Transfer of the transgene to non‑target species
Q.28 Which of the following is a commonly used plant transformation method for monocot cereals like maize and rice?
Agrobacterium tumefaciens infection
Particle bombardment (biolistics)
Electroporation of leaf discs
Silica gel mediated transfer
Explanation - Monocots are less susceptible to Agrobacterium, so biolistics is often employed for their genetic transformation.
Correct answer is: Particle bombardment (biolistics)
Q.29 What is the function of the ‘Bt’ gene introduced into many crop plants?
Confers resistance to herbicides
Provides tolerance to drought
Produces an insecticidal protein from Bacillus thuringiensis
Increases seed oil content
Explanation - Bt toxins are toxic to certain insects, reducing the need for chemical insecticides.
Correct answer is: Produces an insecticidal protein from Bacillus thuringiensis
Q.30 Which of the following is a major challenge associated with field trials of transgenic crops?
Low seed germination rates
Regulatory approval and containment
Inability to measure growth parameters
Lack of interest from farmers
Explanation - Field trials require strict biosafety measures, permits, and monitoring to prevent unintended spread.
Correct answer is: Regulatory approval and containment
Q.31 Which technique is used to produce haploid plants that can be doubled to obtain completely homozygous lines?
Anther culture
Somatic embryogenesis
Agrobacterium infection
CRISPR/Cas9 editing
Explanation - Anther culture induces microspores to develop into haploid plants; chromosome doubling creates homozygous lines quickly.
Correct answer is: Anther culture
Q.32 What does the term ‘biofortification’ refer to in crop biotechnology?
Increasing pesticide use
Enhancing nutritional content of crops through genetic means
Reducing seed size
Accelerating flowering time
Explanation - Biofortified crops (e.g., Golden Rice) are engineered to contain higher levels of vitamins or minerals.
Correct answer is: Enhancing nutritional content of crops through genetic means
Q.33 Which of the following is a common phenotypic marker used in early plant transformation experiments?
Purple leaf color due to anthocyanin accumulation
Red fluorescence from DsRed protein
Blue fluorescence from GFP
Yellow seed color from β‑carotene
Explanation - Anthocyanin overproduction yields a visible purple coloration, facilitating visual selection.
Correct answer is: Purple leaf color due to anthocyanin accumulation
Q.34 Which of the following enzymes is directly responsible for the integration of T‑DNA into the plant genome during Agrobacterium‑mediated transformation?
VirD2
Integrase
Ligase
DNA polymerase
Explanation - VirD2 binds to the T‑DNA border and guides its integration into the plant chromosomal DNA.
Correct answer is: VirD2
Q.35 What is the primary purpose of using a ‘terminator’ sequence in a transgene construct?
To enhance transcription efficiency
To signal the end of transcription and stabilize mRNA
To provide antibiotic resistance
To act as a promoter
Explanation - Terminators contain polyadenylation signals that ensure proper mRNA processing and stability.
Correct answer is: To signal the end of transcription and stabilize mRNA
Q.36 In plant breeding, what is ‘MAS’ an abbreviation for?
Molecular Assisted Selection
Marker‑Assisted Selection
Metabolic Augmentation System
Microbial Antagonist Strategy
Explanation - MAS uses DNA markers linked to desirable traits to accelerate the breeding process.
Correct answer is: Marker‑Assisted Selection
Q.37 Which of the following crops has been engineered for resistance to the herbicide glyphosate?
Cotton
Barley
Potato
Wheat
Explanation - Glyphosate‑tolerant cotton (e.g., Gossypium hirsutum) expresses a modified EPSPS enzyme insensitive to glyphosate.
Correct answer is: Cotton
Q.38 What is the main function of the ‘EPSPS’ enzyme that is targeted by glyphosate?
Synthesis of aromatic amino acids
DNA replication
Photosystem II electron transport
Starch degradation
Explanation - EPSPS (5‑enolpyruvylshikimate‑3‑phosphate synthase) is essential for the shikimate pathway producing phenylalanine, tyrosine, and tryptophan.
Correct answer is: Synthesis of aromatic amino acids
Q.39 Which of the following is a typical outcome of knocking out the GA20ox gene in rice using CRISPR?
Increased plant height
Reduced plant height (dwarfism)
Enhanced grain protein content
Improved cold tolerance
Explanation - GA20ox is involved in gibberellin biosynthesis; its loss reduces gibberellin levels, leading to dwarf phenotypes.
Correct answer is: Reduced plant height (dwarfism)
Q.40 Which method is commonly used to assess the expression level of a transgene at the protein level?
Northern blot
Southern blot
ELISA
RT‑PCR
Explanation - ELISA (enzyme‑linked immunosorbent assay) quantifies specific proteins using antibodies.
Correct answer is: ELISA
Q.41 In the context of plant biotechnology, what does ‘de‑stacking’ refer to?
Removing one or more traits from a stacked variety
Separating the seed coat from the embryo
Breaking down cell walls for extraction
Eliminating transgene silencing
Explanation - De‑stacking involves breeding or genetic manipulation to isolate specific traits from a multi‑trait line.
Correct answer is: Removing one or more traits from a stacked variety
Q.42 Which of the following is a benefit of using a ‘synthetic promoter’ in transgenic plants?
It guarantees expression only in roots
It can be tailored for desired strength and tissue specificity
It eliminates the need for a terminator
It provides antibiotic resistance
Explanation - Synthetic promoters are engineered sequences that can fine‑tune transcriptional activity according to experimental needs.
Correct answer is: It can be tailored for desired strength and tissue specificity
Q.43 Which of the following is an example of a non‑transgenic, yet genome‑edited, crop that may avoid GMO regulation in some countries?
Bt cotton
Golden Rice
CRISPR‑edited mushroom without foreign DNA
Herbicide‑tolerant soybean
Explanation - If editing does not introduce foreign genetic material, some jurisdictions treat the product as non‑GMO.
Correct answer is: CRISPR‑edited mushroom without foreign DNA
Q.44 What is the main reason for using ‘RNA‑seq’ in plant biotechnology research?
To measure DNA methylation
To quantify gene expression across the transcriptome
To edit genes directly
To identify protein–protein interactions
Explanation - RNA‑seq provides high‑throughput sequencing of cDNA, revealing transcript abundance and splicing variants.
Correct answer is: To quantify gene expression across the transcriptome
Q.45 Which of the following crop improvement strategies involves transferring genes from wild relatives into elite cultivars through backcrossing?
Introgression breeding
Hybrid breeding
Mutagenesis
Clonal propagation
Explanation - Introgression moves specific alleles from wild species into cultivated backgrounds while retaining elite traits.
Correct answer is: Introgression breeding
Q.46 What is the role of the enzyme ‘polygalacturonase’ in fruit ripening?
Synthesis of chlorophyll
Breakdown of pectin in cell walls
Production of ethylene
Conversion of starch to sugar
Explanation - Polygalacturonase degrades pectin, softening fruit tissue during ripening.
Correct answer is: Breakdown of pectin in cell walls
Q.47 Which of the following is a common method to reduce off‑target effects in CRISPR/Cas genome editing of plants?
Using a high concentration of Cas9 protein
Designing guide RNAs with high specificity and minimal mismatches
Increasing the temperature of the tissue culture
Applying strong selection pressure
Explanation - Careful gRNA design reduces binding to unintended genomic sites, limiting off‑target cleavage.
Correct answer is: Designing guide RNAs with high specificity and minimal mismatches
Q.48 In plant genetic engineering, what does the term ‘codon optimization’ refer to?
Changing the promoter to a stronger one
Modifying the DNA sequence to use codons preferred by the host plant
Adding introns to the transgene
Removing all GC content
Explanation - Optimizing codon usage improves translation efficiency and protein yield in the target species.
Correct answer is: Modifying the DNA sequence to use codons preferred by the host plant
Q.49 Which of the following is a typical symptom of transgene silencing in plants?
Increased resistance to pests
Loss of the intended phenotype over generations
Faster seed germination
Higher chlorophyll content
Explanation - Silencing mechanisms (e.g., DNA methylation) can suppress transgene expression, causing phenotype loss.
Correct answer is: Loss of the intended phenotype over generations
Q.50 What is the main advantage of using ‘haploid induction lines’ in crop breeding?
They produce seeds faster
They allow rapid generation of completely homozygous lines
They increase plant height
They enhance disease resistance directly
Explanation - Haploid induction followed by chromosome doubling yields fully homozygous plants in one generation.
Correct answer is: They allow rapid generation of completely homozygous lines
Q.51 Which of the following technologies enables the precise insertion of a gene at a predetermined genomic location?
Random T‑DNA integration
CRISPR/Cas‑mediated homology‑directed repair
Particle bombardment
Electroporation
Explanation - HDR uses a donor template with homology arms to insert DNA at a specific cut site created by CRISPR/Cas.
Correct answer is: CRISPR/Cas‑mediated homology‑directed repair
Q.52 Which plant metabolic pathway is targeted to increase vitamin A (β‑carotene) content in Golden Rice?
Shikimate pathway
Carotenoid biosynthesis pathway
Phenylpropanoid pathway
Starch biosynthesis pathway
Explanation - Genes for phytoene synthase and lycopene β‑cyclase were introduced to boost β‑carotene accumulation in rice endosperm.
Correct answer is: Carotenoid biosynthesis pathway
Q.53 What does the term ‘phytoremediation’ refer to?
Using plants to clean up environmental contaminants
Developing pest‑resistant crops
Improving seed storage life
Enhancing photosynthetic efficiency
Explanation - Phytoremediation exploits plants' ability to uptake, accumulate, or detoxify pollutants from soil or water.
Correct answer is: Using plants to clean up environmental contaminants
Q.54 Which of the following is a typical method for confirming the copy number of an inserted transgene?
Southern blotting
Northern blotting
Gel electrophoresis of RNA
Mass spectrometry
Explanation - Southern blot analysis uses DNA probes to detect and estimate the number of transgene insertions.
Correct answer is: Southern blotting
Q.55 In plant biotechnology, what is the primary purpose of a ‘binary vector’?
To deliver two different genes simultaneously
To separate the T‑DNA region from replication functions in Agrobacterium
To act as a selectable marker
To encode a fluorescent protein
Explanation - Binary vectors have a small T‑DNA region (carrying the transgene) and a separate backbone that replicates in Agrobacterium, enhancing safety and flexibility.
Correct answer is: To separate the T‑DNA region from replication functions in Agrobacterium
Q.56 Which of the following crops has been genetically engineered for increased lysine content?
Maize
Soybean
Rice
Wheat
Explanation - High‑lysine (opaque‑2) maize varieties have been developed to improve protein quality.
Correct answer is: Maize
Q.57 What is the main function of the ‘RNA‑dependent RNA polymerase’ (RDR) in plant antiviral defense?
Synthesize viral DNA
Amplify small interfering RNAs (siRNAs) for gene silencing
Produce ethylene
Degrade chlorophyll
Explanation - RDR converts single‑stranded RNA into double‑stranded RNA, which is processed into siRNAs that target viral RNAs.
Correct answer is: Amplify small interfering RNAs (siRNAs) for gene silencing
Q.58 Which of the following is a key factor influencing the success of Agrobacterium‑mediated transformation in dicotyledonous plants?
Presence of a thick cuticle
High concentration of auxin in the medium
Wounding of explant tissue
Low temperature incubation
Explanation - Wounding releases phenolic compounds that activate Agrobacterium vir genes, facilitating T‑DNA transfer.
Correct answer is: Wounding of explant tissue
Q.59 What is the primary goal of ‘speed breeding’ techniques in modern crop improvement?
To increase seed size rapidly
To shorten the generation time, enabling more breeding cycles per year
To enhance drought tolerance directly
To reduce the need for fertilizers
Explanation - Speed breeding uses controlled environment (e.g., extended photoperiod) to accelerate plant development and seed production.
Correct answer is: To shorten the generation time, enabling more breeding cycles per year
Q.60 Which of the following is an example of a 'cis‑regulatory element'?
TATA box
Beta‑tubulin gene
Kanamycin resistance gene
GFP coding sequence
Explanation - Cis‑regulatory elements are DNA sequences located near a gene (e.g., promoters, enhancers) that control transcription.
Correct answer is: TATA box
Q.61 Which of the following traits is most commonly introduced into crops using RNAi technology?
Herbicide tolerance
Increased leaf size
Virus resistance
Higher sugar content
Explanation - RNAi can target viral genome sequences, providing resistance by degrading viral RNAs.
Correct answer is: Virus resistance
Q.62 In plant genome editing, what does the acronym ‘ABE’ stand for?
Adenine Base Editor
Allelic Breeding Engine
Auxin Binding Element
Artificial Biosynthetic Enzyme
Explanation - ABE enables precise A•T to G•C base conversions without double‑strand breaks.
Correct answer is: Adenine Base Editor
Q.63 Which of the following is a primary environmental concern associated with Bt crops?
Development of resistance in target insect populations
Increased soil salinity
Higher greenhouse gas emissions
Reduced pollinator activity
Explanation - Continuous exposure to Bt toxin can select for resistant insect strains, potentially diminishing effectiveness.
Correct answer is: Development of resistance in target insect populations
Q.64 What is the main benefit of using a ‘split‑root’ system in studying root–microbe interactions?
It allows simultaneous inoculation with two different microbes
It doubles the number of roots per plant
It eliminates the need for sterile conditions
It increases shoot biomass
Explanation - Split‑root setups enable comparative studies on each half of the root system under distinct microbial treatments.
Correct answer is: It allows simultaneous inoculation with two different microbes
Q.65 Which of the following is a common method to assess seed vigor in breeding programs?
Measuring seed weight
Germination rate under stress conditions
Counting leaf number
Estimating chlorophyll content
Explanation - Seed vigor tests evaluate the ability of seeds to germinate quickly and uniformly, especially under adverse conditions.
Correct answer is: Germination rate under stress conditions
Q.66 Which of the following is a characteristic of a ‘self‑incompatible’ plant species?
It cannot set seed when pollinated by its own pollen
It produces sterile seeds
It requires a specific pollinator
It has a very short life cycle
Explanation - Self‑incompatibility prevents inbreeding by rejecting self‑pollen, promoting outcrossing.
Correct answer is: It cannot set seed when pollinated by its own pollen
Q.67 In the context of gene expression analysis, what does ‘FPKM’ stand for?
Fragments Per Kilobase of transcript per Million mapped reads
Fluorescent Protein Kinetics Measurement
Fast PCR K-mer analysis
Functional Protein Kinase Mapping
Explanation - FPKM normalizes RNA‑seq data for transcript length and sequencing depth, allowing comparison of gene expression levels.
Correct answer is: Fragments Per Kilobase of transcript per Million mapped reads
Q.68 Which of the following crops has been successfully edited to produce a semi‑dwarf phenotype using CRISPR?
Rice
Tomato
Barley
Soybean
Explanation - CRISPR editing of the sd1 gene in rice replicates the semi‑dwarf Green Revolution trait, improving lodging resistance.
Correct answer is: Rice
Q.69 What does the term ‘phytochemical’ refer to?
A synthetic fertilizer component
A plant‑derived chemical that may have health benefits
A type of soil microorganism
A genetic marker in crops
Explanation - Phytochemicals include flavonoids, carotenoids, and other secondary metabolites with nutritional or medicinal properties.
Correct answer is: A plant‑derived chemical that may have health benefits
Q.70 Which of the following is a key advantage of using ‘synthetic biology’ approaches in crop improvement?
It eliminates the need for field trials
It allows design of entirely new metabolic pathways
It reduces the plant’s genome size
It guarantees resistance to all pests
Explanation - Synthetic biology can construct novel biosynthetic routes, enabling production of compounds not naturally found in the plant.
Correct answer is: It allows design of entirely new metabolic pathways
Q.71 In plant transformation, what is the purpose of a ‘border sequence’ flanking the T‑DNA?
To act as a promoter for the transgene
To define the limits of DNA that will be transferred into the plant genome
To provide antibiotic resistance
To enhance seed germination
Explanation - Left and right border sequences are recognized by Agrobacterium vir proteins and delimit the T‑DNA region.
Correct answer is: To define the limits of DNA that will be transferred into the plant genome
Q.72 Which of the following is a typical symptom of off‑target mutations caused by CRISPR editing in plants?
Uniform increase in plant height
Unintended phenotypic changes unrelated to the target gene
Enhanced resistance to all pathogens
Improved seed color
Explanation - Off‑target cuts can disrupt other genes, leading to unexpected traits or growth defects.
Correct answer is: Unintended phenotypic changes unrelated to the target gene
Q.73 Which of the following best describes a ‘genome‑wide association study’ (GWAS) in crop genetics?
A method to edit multiple genes simultaneously
An approach that links genetic markers across the whole genome with phenotypic traits
A technique for cloning entire plant genomes
A process of inducing random mutations with chemicals
Explanation - GWAS scans many markers to find statistical associations with traits, aiding marker‑assisted breeding.
Correct answer is: An approach that links genetic markers across the whole genome with phenotypic traits
Q.74 What is the primary reason for using a ‘ribosome‑binding site’ (RBS) in a plant expression cassette?
To promote transcription initiation
To facilitate translation initiation of the mRNA
To provide a selectable marker
To enhance DNA replication
Explanation - RBS sequences help ribosomes bind mRNA efficiently, increasing protein synthesis.
Correct answer is: To facilitate translation initiation of the mRNA
Q.75 Which of the following crops has been engineered for increased vitamin C (ascorbic acid) content?
Potato
Corn
Barley
Soybean
Explanation - Expression of bacterial GDP‑L‑galactose phosphorylase increased ascorbic acid levels in transgenic potatoes.
Correct answer is: Potato
Q.76 What does the term ‘pharming’ refer to in the context of plant biotechnology?
Using plants to produce pharmaceutical proteins
Growing crops without pesticides
Applying fertilizers in a precision manner
Hybridizing different plant species
Explanation - Pharming exploits plant expression systems to manufacture vaccines, antibodies, or enzymes.
Correct answer is: Using plants to produce pharmaceutical proteins
Q.77 Which of the following is a characteristic of a ‘dominant’ transgene trait?
It is expressed only when two copies are present
It will be expressed even if only one allele carries the transgene
It never segregates in the progeny
It is only expressed under stress conditions
Explanation - Dominant traits manifest in heterozygous individuals, requiring only one functional copy.
Correct answer is: It will be expressed even if only one allele carries the transgene
Q.78 In plant tissue culture, what is the role of ‘cysteine’ in the medium?
It acts as a carbon source
It promotes callus formation
It serves as an antioxidant and reduces phenolic browning
It induces flowering
Explanation - Cysteine scavenges reactive phenolics, preventing tissue browning during culture.
Correct answer is: It serves as an antioxidant and reduces phenolic browning
Q.79 Which of the following is a key factor influencing transgene expression stability over generations?
Promoter choice and genomic insertion site
Seed color of the host plant
Length of the plant’s taproot
Presence of chlorophyll
Explanation - Strong, stable promoters and insertion into transcriptionally active chromatin promote consistent expression.
Correct answer is: Promoter choice and genomic insertion site
Q.80 Which of the following enzymes is used to generate double‑strand breaks in CRISPR‑Cas12a (Cpf1) systems?
Cas9
Cas12a (Cpf1)
Taq polymerase
Reverse transcriptase
Explanation - Cas12a (also known as Cpf1) is an alternative to Cas9 that creates staggered cuts with a different PAM requirement.
Correct answer is: Cas12a (Cpf1)
Q.81 What is the main purpose of a ‘genetic firewall’ in transgenic plants?
To prevent gene flow to wild relatives by incorporating sterility genes
To enhance photosynthetic rate
To increase seed size
To boost root length
Explanation - Genetic firewalls (e.g., male sterility) limit the spread of transgenes into the environment.
Correct answer is: To prevent gene flow to wild relatives by incorporating sterility genes
Q.82 Which of the following plant hormones is primarily associated with the regulation of seed dormancy?
Abscisic acid (ABA)
Cytokinin
Gibberellin
Auxin
Explanation - ABA promotes dormancy and inhibits germination, while gibberellins have the opposite effect.
Correct answer is: Abscisic acid (ABA)
Q.83 Which of the following is a common method to assess plant resistance to a pathogen in a greenhouse assay?
Measuring leaf chlorophyll content
Scoring disease severity on a visual scale after inoculation
Counting the number of seeds per pod
Measuring root length
Explanation - Disease severity indices (e.g., 0–5 scale) quantify the level of infection after controlled inoculation.
Correct answer is: Scoring disease severity on a visual scale after inoculation
Q.84 What is the primary purpose of using a ‘gateway cloning’ system in plant biotechnology?
To clone large genomic fragments without restriction enzymes
To enable recombination‑based transfer of DNA fragments between vectors
To insert transgenes randomly into the genome
To amplify RNA sequences directly
Explanation - Gateway cloning uses site‑specific recombination (att sites) for efficient, directional transfer of DNA fragments.
Correct answer is: To enable recombination‑based transfer of DNA fragments between vectors
Q.85 Which of the following is an advantage of using ‘microRNA (miRNA)‑based silencing’ over conventional RNAi in plants?
It can target multiple genes simultaneously with higher specificity
It does not require a promoter
It integrates into the chloroplast genome automatically
It always results in permanent gene knockout
Explanation - Artificial miRNAs can be designed to silence gene families with precise matching, reducing off‑target effects.
Correct answer is: It can target multiple genes simultaneously with higher specificity
Q.86 Which of the following is a typical feature of a ‘synthetic auxin‑responsive promoter’?
Contains multiple auxin‑responsive elements (AuxRE) for strong, inducible expression
Provides constitutive expression in all tissues
Acts as a selectable marker
Encodes a fluorescent protein
Explanation - Synthetic promoters can be engineered to respond to specific hormones, allowing controlled transgene activation.
Correct answer is: Contains multiple auxin‑responsive elements (AuxRE) for strong, inducible expression
Q.87 In the context of plant transformation, what does the term ‘co‑transformation’ refer to?
Introducing two separate plasmids simultaneously into the same plant cell
Transforming two different plant species at the same time
Using both Agrobacterium and biolistics together
Combining DNA and RNA delivery in one step
Explanation - Co‑transformation allows delivery of a gene of interest along with a selectable marker or additional trait on separate constructs.
Correct answer is: Introducing two separate plasmids simultaneously into the same plant cell
Q.88 Which of the following is a major limitation of using particle bombardment for plant transformation?
It can only be used in monocots
It often results in multiple and rearranged transgene copies
It requires a bacterial host
It cannot deliver large DNA fragments
Explanation - Biolistics can cause random integration of many copies, leading to silencing or instability.
Correct answer is: It often results in multiple and rearranged transgene copies
Q.89 Which of the following crops has been engineered for enhanced phosphorus uptake efficiency?
Soybean
Rice
Barley
Wheat
Explanation - Overexpression of phosphate transporter genes (e.g., OsPHT1) in rice improves phosphorus acquisition.
Correct answer is: Rice
Q.90 What is the main function of the ‘FAD2’ gene in oilseed plants?
Catalyzes the conversion of saturated fatty acids to unsaturated fatty acids
Encodes a storage protein
Regulates seed dormancy
Controls plant height
Explanation - FAD2 encodes a delta‑12 oleate desaturase that converts oleic acid to linoleic acid; its suppression raises oleic acid levels.
Correct answer is: Catalyzes the conversion of saturated fatty acids to unsaturated fatty acids
Q.91 Which of the following is a key benefit of developing 'drought‑tolerant' GM crops for smallholder farmers?
Reduced need for pesticide applications
Higher yields under water‑limited conditions
Elimination of all weeds
Increased seed size
Explanation - Drought tolerance helps maintain productivity when rainfall is scarce, improving food security for resource‑limited growers.
Correct answer is: Higher yields under water‑limited conditions
Q.92 In plant biotechnology, what does the term ‘stacked trait’ mean?
A gene that performs multiple functions
Two or more traits introduced into a single cultivar
A promoter that drives expression in several tissues
A disease that affects multiple crop species
Explanation - Stacked traits combine, for example, herbicide tolerance and insect resistance in one variety.
Correct answer is: Two or more traits introduced into a single cultivar
Q.93 Which of the following is a common method for delivering CRISPR components into plant cells without integrating DNA?
Agrobacterium‑mediated stable transformation
Particle bombardment of plasmid DNA
Protoplast transfection with ribonucleoprotein (RNP) complexes
Silicon carbide whisker method
Explanation - RNP delivery results in transient editing and avoids insertion of foreign DNA, reducing regulatory burden.
Correct answer is: Protoplast transfection with ribonucleoprotein (RNP) complexes
Q.94 Which of the following is a major factor influencing the regulatory approval process for a new GM crop?
The color of the plant flowers
Potential for allergenicity and environmental impact
The market price of the seed
The number of genes inserted
Explanation - Risk assessments focus on food safety, gene flow, and ecological consequences.
Correct answer is: Potential for allergenicity and environmental impact
Q.95 What does the term ‘epigenetic editing’ refer to in plant biotechnology?
Changing DNA sequence using CRISPR
Modifying DNA methylation or histone marks without altering the underlying sequence
Introducing new chromosomes
Increasing the ploidy level of the plant
Explanation - Epigenetic editors (e.g., dCas9‑TET) can activate or repress genes by altering chromatin state.
Correct answer is: Modifying DNA methylation or histone marks without altering the underlying sequence
Q.96 Which of the following crops has been genetically engineered to produce its own insecticidal protein derived from Bacillus thuringiensis (Bt)?
Cotton
Barley
Soybean
Rice
Explanation - Bt cotton expresses Cry proteins that are toxic to lepidopteran pests, reducing insecticide use.
Correct answer is: Cotton
Q.97 What is the main advantage of using a ‘seed‑specific promoter’ for a nutritional trait gene?
It ensures expression only in seeds, where the nutrient is needed
It makes the plant resistant to all diseases
It speeds up germination
It increases leaf size
Explanation - Targeted expression avoids unnecessary metabolic burden on other tissues and focuses the trait where it benefits consumers.
Correct answer is: It ensures expression only in seeds, where the nutrient is needed
Q.98 Which of the following is a common method to assess the nutritional quality of a biofortified crop?
Measuring leaf chlorophyll content
Quantifying target micronutrient (e.g., iron, zinc) using atomic absorption spectroscopy
Counting the number of seeds per pod
Measuring plant height
Explanation - Analytical techniques like AAS or ICP‑MS accurately determine mineral concentrations in plant tissues.
Correct answer is: Quantifying target micronutrient (e.g., iron, zinc) using atomic absorption spectroscopy
Q.99 In a gene stacking strategy, what is a common approach to combine multiple traits while maintaining linkage?
Crossing independent single‑trait lines and selecting progeny with all traits
Inserting all genes into a single T‑DNA region
Using a virus to deliver each trait separately
Applying chemical mutagenesis
Explanation - A single construct containing multiple gene cassettes reduces segregation and simplifies breeding.
Correct answer is: Inserting all genes into a single T‑DNA region
Q.100 Which of the following is a typical phenotype of plants overexpressing the DREB1 transcription factor?
Enhanced tolerance to cold and drought stresses
Increased seed size
Higher herbicide resistance
Reduced leaf number
Explanation - DREB1 regulates stress‑responsive genes, improving plant performance under abiotic stresses.
Correct answer is: Enhanced tolerance to cold and drought stresses
Q.101 What does the term ‘transient expression’ mean in plant biotechnology experiments?
Expression of a transgene that persists for only a short period without integration
Permanent insertion of a gene into the plant genome
Expression only in root tissues
Expression that occurs only under stress conditions
Explanation - Transient assays (e.g., agroinfiltration) allow rapid functional testing of genes without stable transformation.
Correct answer is: Expression of a transgene that persists for only a short period without integration
Q.102 Which of the following is an example of a ‘phytochemical’ that can be increased through metabolic engineering?
Beta‑carotene
Starch
Cellulose
Glucose
Explanation - Metabolic pathways can be engineered to boost production of valuable secondary metabolites like carotenoids.
Correct answer is: Beta‑carotene
Q.103 Which of the following plant species is considered a model organism for genetic studies and genome editing?
Arabidopsis thaliana
Corn (Zea mays)
Wheat (Triticum aestivum)
Soybean (Glycine max)
Explanation - Arabidopsis has a small genome, short life cycle, and extensive genetic resources, making it a preferred model.
Correct answer is: Arabidopsis thaliana
Q.104 In plant breeding, what does the term ‘backcrossing’ refer to?
Crossing a hybrid with one of its parents to recover the recurrent parent genome
Crossing two unrelated species
Self‑pollinating a plant to produce inbred lines
Crossing multiple parents simultaneously
Explanation - Backcrossing introgresses a specific trait while retaining the elite background of the recurrent parent.
Correct answer is: Crossing a hybrid with one of its parents to recover the recurrent parent genome
Q.105 Which of the following is a key component of a plant transformation vector that allows selection of transformed tissue on media containing phosphinothricin (PPT)?
Bar gene (bialaphos resistance)
NptII gene (kanamycin resistance)
Hpt gene (hygromycin resistance)
GUS reporter gene
Explanation - Bar encodes phosphinothricin acetyltransferase, conferring resistance to PPT, a common selectable marker in cereals.
Correct answer is: Bar gene (bialaphos resistance)
Q.106 What is the primary function of the enzyme ‘ACC synthase’ in the ethylene biosynthetic pathway?
Converts S‑adenosyl‑methionine (SAM) to 1‑aminocyclopropane‑1‑carboxylic acid (ACC)
Degrades ethylene
Synthesis of auxin
Breakdown of chlorophyll
Explanation - ACC synthase catalyzes the rate‑limiting step in ethylene production, influencing fruit ripening and senescence.
Correct answer is: Converts S‑adenosyl‑methionine (SAM) to 1‑aminocyclopropane‑1‑carboxylic acid (ACC)
Q.107 Which of the following is a typical method for measuring the activity of a transgene‑encoded enzyme in plant extracts?
Spectrophotometric assay
Southern blot
DNA sequencing
PCR amplification
Explanation - Enzyme activity can be quantified by monitoring substrate conversion that changes absorbance at a specific wavelength.
Correct answer is: Spectrophotometric assay
Q.108 Which of the following traits would most likely be introduced into a crop using a gene from a different plant species (transgenesis) rather than from the same species (cisgenesis)?
Drought tolerance from a wild relative of the same crop
Bt insect resistance from Bacillus thuringiensis
Increased seed oil content from a close cultivar
Male sterility from a related variety
Explanation - Bt genes originate from a bacterium, representing transgenesis, whereas traits from related plants fall under cisgenesis.
Correct answer is: Bt insect resistance from Bacillus thuringiensis
Q.109 What is the primary advantage of using a ‘self‑cleaving ribozyme’ downstream of a transgene?
Ensures precise 3’ end formation of the mRNA
Provides antibiotic resistance
Acts as a promoter
Increases seed size
Explanation - Ribozymes can generate defined RNA termini, improving transcript stability and translation.
Correct answer is: Ensures precise 3’ end formation of the mRNA
Q.110 Which of the following is a common phenotypic marker used to identify successful transformation in tomato explants?
Red fluorescence from DsRed
Purple coloration due to anthocyanin accumulation
White seed coat
Increased leaf size
Explanation - DsRed provides a visible red fluorescence, allowing rapid identification of transformed tissues under appropriate light.
Correct answer is: Red fluorescence from DsRed
Q.111 In the context of plant breeding, what does the term ‘heterotic group’ describe?
A group of lines that produce superior hybrids when crossed with each other
A collection of genetically identical clones
A set of lines with the same disease resistance gene
A group of plants that flower at the same time
Explanation - Heterotic groups are defined by their ability to generate hybrid vigor when inter‑crossed.
Correct answer is: A group of lines that produce superior hybrids when crossed with each other
Q.112 Which of the following is a method used to reduce the risk of transgene silencing in plants?
Using intron‑containing transgene constructs
Increasing copy number of the transgene
Targeting the transgene to the chloroplast genome
All of the above
Explanation - Intron inclusion, low copy number, and chloroplast targeting can all help mitigate nuclear gene silencing.
Correct answer is: All of the above
Q.113 What does the term ‘phytophthora resistance’ refer to in crop improvement?
Resistance to a fungal pathogen causing root rot
Tolerance to high soil salinity
Improved nitrogen fixation
Enhanced photosynthetic efficiency
Explanation - Phytophthora spp. are oomycete pathogens that cause devastating diseases like late blight; resistance genes are valuable for crop protection.
Correct answer is: Resistance to a fungal pathogen causing root rot
Q.114 Which of the following techniques allows the precise insertion of a transgene at a predetermined genomic ‘safe‑harbor’ locus?
CRISPR/Cas‑mediated homology‑directed repair
Agrobacterium random integration
Particle bombardment
Chemical mutagenesis
Explanation - HDR with a donor template can target transgenes to safe‑harbor sites, minimizing position effects and silencing.
Correct answer is: CRISPR/Cas‑mediated homology‑directed repair
Q.115 Which of the following is a typical symptom of a plant infected with a virus that can be mitigated by RNAi‑mediated resistance?
Mosaic leaf pattern
Increased root length
Enhanced seed germination
Thicker stems
Explanation - Many plant viruses cause mosaic or mottling symptoms; RNAi targeting viral genomes reduces these disease signs.
Correct answer is: Mosaic leaf pattern
Q.116 What is a key advantage of using ‘micropropagation’ for the rapid multiplication of transgenic plants?
It eliminates the need for a selectable marker
It ensures genetically uniform progeny
It introduces new mutations
It reduces the need for greenhouse space
Explanation - Micropropagation (tissue culture) produces clonal copies, preserving the transgene and its expression across many plants.
Correct answer is: It ensures genetically uniform progeny
Q.117 Which of the following is a major challenge when editing polyploid crops such as wheat?
Low transformation efficiency
Multiple gene copies (homeologs) requiring simultaneous editing
Lack of selectable markers
Inability to grow tissue culture
Explanation - Polyploid genomes contain several homologous copies of each gene, necessitating editing of all copies to achieve a phenotype.
Correct answer is: Multiple gene copies (homeologs) requiring simultaneous editing
Q.118 In plant biotechnology, what does the acronym ‘VIGS’ stand for?
Virus‑Induced Gene Silencing
Variable Intron Gene System
Vector‑Integrated Genomic Sequencing
Vacuole‑Induced Growth Stimulation
Explanation - VIGS uses viral vectors to transiently knock down target gene expression for functional studies.
Correct answer is: Virus‑Induced Gene Silencing
Q.119 Which of the following is an example of a ‘nutrient use efficiency’ trait that can be engineered into crops?
Enhanced nitrogen assimilation via overexpression of glutamine synthetase
Increased leaf size
Higher seed oil content
Early flowering
Explanation - Improving key metabolic enzymes can enable plants to use fertilizers more efficiently, reducing input costs and environmental impact.
Correct answer is: Enhanced nitrogen assimilation via overexpression of glutamine synthetase
Q.120 Which of the following is a common method to evaluate the success of CRISPR editing in a plant?
Restriction fragment length polymorphism (RFLP) analysis
Southern blot
Northern blot
ELISA
Explanation - RFLP (or T7E1 assay) can detect insertions/deletions at the target site by changes in restriction patterns.
Correct answer is: Restriction fragment length polymorphism (RFLP) analysis
Q.121 What does the term ‘synthetic biology chassis’ refer to in plant engineering?
A standardized plant host designed for modular insertion of synthetic pathways
The chloroplast DNA of a plant
A type of fertilizer used in labs
A specific promoter sequence
Explanation - A chassis provides a predictable, well‑characterized platform for assembling and testing synthetic gene circuits.
Correct answer is: A standardized plant host designed for modular insertion of synthetic pathways
Q.122 Which of the following is an example of a ‘bioengineered’ trait aimed at reducing post‑harvest losses?
Delayed fruit ripening via suppression of the polygalacturonase gene
Increased seed size
Enhanced drought tolerance
Herbicide tolerance
Explanation - Reducing polygalacturonase activity slows cell wall breakdown, extending shelf life of fruits like tomatoes.
Correct answer is: Delayed fruit ripening via suppression of the polygalacturonase gene
Q.123 Which of the following is a primary reason for incorporating a ‘reporter gene’ like GFP into a transformation construct?
To confer disease resistance
To visually confirm expression and subcellular localization of the transgene
To increase photosynthetic efficiency
To provide herbicide tolerance
Explanation - GFP emits green fluorescence, allowing researchers to monitor where and when the transgene is expressed.
Correct answer is: To visually confirm expression and subcellular localization of the transgene
Q.124 What is the main advantage of editing the promoter region of an endogenous gene rather than inserting a transgene?
It creates a non‑GMO product in many regulatory frameworks
It always leads to higher expression
It eliminates the need for any DNA manipulation
It reduces plant height
Explanation - Promoter editing modifies existing DNA without adding foreign sequences, often bypassing GMO regulations.
Correct answer is: It creates a non‑GMO product in many regulatory frameworks