Q.1 What is the primary goal of conventional plant breeding?
Introduce foreign DNA into the plant genome
Select and cross plants with desirable traits
Edit specific genes using CRISPR
Induce random mutations with radiation
Explanation - Conventional breeding relies on selecting plants that naturally exhibit desired characteristics and crossing them to combine those traits in offspring.
Correct answer is: Select and cross plants with desirable traits
Q.2 Which technique is used to create mutations in crop genomes by exposing seeds to chemicals?
Agrobacterium-mediated transformation
EMS mutagenesis
RNA interference
Gene stacking
Explanation - Ethyl methanesulfonate (EMS) is a chemical mutagen that alkylates DNA, causing point mutations useful for breeding new traits.
Correct answer is: EMS mutagenesis
Q.3 Marker‑assisted selection (MAS) primarily speeds up breeding by:
Directly inserting genes into the plant
Using DNA markers linked to traits
Applying high‑intensity light to seeds
Cross‑pollinating unrelated species
Explanation - MAS uses molecular markers tightly linked to desired genes, allowing early selection of seedlings without phenotypic screening.
Correct answer is: Using DNA markers linked to traits
Q.4 Which of the following is a common use of CRISPR‑Cas9 in crops?
Increasing seed size through polyploidy
Silencing genes by RNA interference
Precisely knocking out a disease‑susceptibility gene
Introducing bacterial plasmids
Explanation - CRISPR‑Cas9 can create targeted double‑strand breaks, allowing precise deletions of genes that make plants vulnerable to pathogens.
Correct answer is: Precisely knocking out a disease‑susceptibility gene
Q.5 Golden Rice was developed to increase which nutrient in the grain?
Vitamin C
Iron
Beta‑carotene (pro‑vitamin A)
Protein
Explanation - Golden Rice contains genes for the carotenoid pathway, producing beta‑carotene to combat vitamin A deficiency.
Correct answer is: Beta‑carotene (pro‑vitamin A)
Q.6 What is the term for a plant that contains three sets of chromosomes?
Diploid
Haploid
Tetraploid
Triploid
Explanation - Triploid organisms have three complete sets of chromosomes (3n), often leading to sterility useful for seedless fruit production.
Correct answer is: Triploid
Q.7 RNA interference (RNAi) in crops is primarily used to:
Add new genes from bacteria
Silence endogenous genes
Increase chromosome number
Create large chromosomal deletions
Explanation - RNAi triggers the degradation of specific mRNA molecules, effectively turning off target genes without altering DNA sequence.
Correct answer is: Silence endogenous genes
Q.8 Which crop was the first to be genetically modified for herbicide tolerance?
Soybean
Cotton
Maize
Canola
Explanation - The first commercial herbicide‑tolerant GMO was a soybean engineered to express a glyphosate‑resistant EPSPS enzyme.
Correct answer is: Soybean
Q.9 In plant breeding, what does the term 'heterosis' refer to?
Loss of genetic diversity
Increased vigor of hybrid offspring
Self‑pollination of a plant
Gene silencing
Explanation - Heterosis, or hybrid vigor, describes the superior growth, yield, or resistance observed in the F1 generation of two genetically distinct parents.
Correct answer is: Increased vigor of hybrid offspring
Q.10 Which of the following is NOT a method of producing genetically improved crops?
Somaclonal variation
Gamma radiation mutagenesis
Artificial selection without any genetic manipulation
CRISPR gene editing
Explanation - Artificial selection alone is conventional breeding; the other options involve direct genetic changes or induced variation.
Correct answer is: Artificial selection without any genetic manipulation
Q.11 What is the purpose of a selectable marker gene in plant transformation vectors?
To increase photosynthetic efficiency
To allow identification of transformed cells
To enhance fruit flavor
To induce polyploidy
Explanation - Selectable markers (e.g., antibiotic or herbicide resistance) let researchers isolate cells that have successfully integrated the transgene.
Correct answer is: To allow identification of transformed cells
Q.12 Which of the following crops has been edited using CRISPR to develop powdery mildew resistance?
Wheat
Rice
Barley
Tomato
Explanation - CRISPR editing of the MLO gene in wheat confers resistance to powdery mildew without introducing foreign DNA.
Correct answer is: Wheat
Q.13 The term 'biofortification' refers to:
Applying fertilizers to increase yield
Genetically enhancing nutritional content of crops
Using pesticides to protect crops
Mechanically harvesting crops
Explanation - Biofortification aims to increase vitamins, minerals, or other nutrients in edible parts of crops through breeding or genetic engineering.
Correct answer is: Genetically enhancing nutritional content of crops
Q.14 Which genome editing tool uses a guide RNA to direct a nuclease to a specific DNA sequence?
Zinc‑finger nucleases
TALENs
CRISPR‑Cas9
RNAi
Explanation - CRISPR‑Cas9 relies on a short guide RNA that base‑pairs with the target DNA, directing the Cas9 nuclease to cut at that location.
Correct answer is: CRISPR‑Cas9
Q.15 What is a 'transgene'?
A gene that is naturally present in the plant genome
A gene transferred from one organism to another
A gene that has been silenced by RNAi
A gene that controls chromosome number
Explanation - A transgene is a piece of DNA introduced into a genome from a different species or source, conferring new traits.
Correct answer is: A gene transferred from one organism to another
Q.16 Which method is commonly used to deliver DNA into plant cells via a bacterium?
Biolistic (gene gun) method
Agrobacterium tumefaciens infection
Electroporation
Microinjection
Explanation - Agrobacterium naturally transfers a segment of DNA (T‑DNA) into plant cells, a technique widely used for stable transformation.
Correct answer is: Agrobacterium tumefaciens infection
Q.17 Polyploid crops often show increased:
Disease susceptibility
Fruit size and vigor
Reduced seed set
Lower nutrient content
Explanation - Polyploidy can lead to larger cell size and metabolic changes, frequently resulting in bigger fruits and more robust plants.
Correct answer is: Fruit size and vigor
Q.18 What is the main advantage of using a tissue‑specific promoter in a transgenic plant?
The gene is expressed in all tissues equally
Expression is limited to a desired organ, reducing off‑target effects
It makes the plant resistant to all pests
It induces polyploidy
Explanation - Tissue‑specific promoters restrict transgene expression to particular tissues (e.g., roots or fruits), minimizing unnecessary metabolic burden.
Correct answer is: Expression is limited to a desired organ, reducing off‑target effects
Q.19 In the context of crop genetics, what does 'QTL' stand for?
Quantitative Trait Locus
Quick Transgenic Line
Quality Trait Lattice
Quasi‑Terminal Locus
Explanation - QTLs are genomic regions that contribute to variation in quantitative traits such as yield, height, or drought tolerance.
Correct answer is: Quantitative Trait Locus
Q.20 Which of the following is a potential risk associated with genetically modified (GM) crops?
Immediate increase in soil fertility
Development of herbicide‑resistant weeds
Universal disease resistance
Elimination of all pesticide use
Explanation - Repeated use of herbicide‑tolerant GM crops can select for weed populations that evolve resistance to the same herbicide.
Correct answer is: Development of herbicide‑resistant weeds
Q.21 What does the term 'cisgenic' mean in plant biotechnology?
A gene from a completely unrelated species is inserted
Only native plant genes are transferred between sexually compatible species
The plant genome is edited without any DNA insertion
The plant is crossed with an animal
Explanation - Cisgenesis involves moving genes between organisms that could be crossed naturally, avoiding foreign DNA.
Correct answer is: Only native plant genes are transferred between sexually compatible species
Q.22 Which technology is used to sequence the entire genome of a crop quickly and affordably?
Sanger sequencing
Next‑generation sequencing (NGS)
Gel electrophoresis
Southern blotting
Explanation - NGS platforms can generate massive amounts of DNA sequence data in parallel, enabling whole‑genome sequencing at lower cost.
Correct answer is: Next‑generation sequencing (NGS)
Q.23 The first crop approved for commercial release using gene editing (not transgenesis) was:
CRISPR‑edited soybean
CRISPR‑edited mushroom
CRISPR‑edited rice
CRISPR‑edited wheat
Explanation - In 2016, the U.S. FDA approved a CRISPR‑edited mushroom that does not brown as quickly, marking the first gene‑edited food on the market.
Correct answer is: CRISPR‑edited mushroom
Q.24 What is the main function of the *Bt* gene introduced into some crops?
Improve drought tolerance
Produce a protein toxic to specific insects
Increase vitamin content
Enhance photosynthetic rate
Explanation - *Bt* (Bacillus thuringiensis) genes encode Cry proteins that kill lepidopteran larvae, providing built‑in insect resistance.
Correct answer is: Produce a protein toxic to specific insects
Q.25 Which breeding approach combines the speed of marker selection with the power of conventional crossing?
Genomic selection
Hybrid breeding
Backcross breeding
Mutation breeding
Explanation - Genomic selection uses genome‑wide markers to predict breeding values, allowing selection before phenotypic evaluation.
Correct answer is: Genomic selection
Q.26 In the context of gene editing, what does the term 'off‑target effect' mean?
The edited gene improves multiple traits
Unintended changes occur at DNA sites other than the intended target
The edited plant cannot reproduce
The editing tool fails to cut any DNA
Explanation - Off‑target effects are undesired modifications at loci sharing similarity with the guide RNA, potentially causing unexpected phenotypes.
Correct answer is: Unintended changes occur at DNA sites other than the intended target
Q.27 Which crop was first engineered to produce the insecticidal Cry1Ab protein?
Cotton
Maize (corn)
Potato
Soybean
Explanation - Bt corn expressing Cry1Ab was among the earliest commercial GM crops, providing protection against the European corn borer.
Correct answer is: Maize (corn)
Q.28 What is the purpose of a 'promoter' in a plant transformation construct?
To cut DNA at a specific site
To drive transcription of the downstream gene
To select transformed cells
To silence the transgene
Explanation - Promoters are DNA sequences where RNA polymerase binds, initiating transcription of the adjacent coding region.
Correct answer is: To drive transcription of the downstream gene
Q.29 Which of the following crops has been successfully engineered for improved nitrogen use efficiency?
Rice
Barley
Wheat
All of the above
Explanation - Various transgenic approaches (e.g., overexpressing glutamine synthetase) have been applied to rice, barley, and wheat to enhance nitrogen assimilation.
Correct answer is: All of the above
Q.30 Somaclonal variation arises from:
Cross‑pollination between different species
Regeneration of plants from tissue culture
Exposure to gamma radiation
Insertion of bacterial genes
Explanation - Somaclonal variation is genetic variation induced during in vitro culture, useful as a source of novel traits.
Correct answer is: Regeneration of plants from tissue culture
Q.31 Which of these is a key advantage of using CRISPR over traditional transgenic methods?
CRISPR always increases yield
CRISPR does not require a selectable marker
CRISPR can edit the plant genome without foreign DNA integration
CRISPR works only in monocot species
Explanation - CRISPR editing can be performed via transient delivery, leaving no transgene in the final plant, which may simplify regulatory approval.
Correct answer is: CRISPR can edit the plant genome without foreign DNA integration
Q.32 Gene pyramiding in crop improvement aims to:
Stack multiple resistance genes into a single variety
Reduce the number of chromosomes
Eliminate the need for irrigation
Create sterile hybrid plants
Explanation - Pyramiding combines several disease‑resistance genes, making it harder for pathogens to overcome all defenses simultaneously.
Correct answer is: Stack multiple resistance genes into a single variety
Q.33 Which of the following is a commonly used herbicide‑resistance gene in GM crops?
EPSPS (glyphosate resistance)
Bt toxin
Cry1Ac
RNAi construct
Explanation - Modified EPSPS enzymes are not inhibited by glyphosate, allowing crops to survive glyphosate application.
Correct answer is: EPSPS (glyphosate resistance)
Q.34 What does the term 'transient expression' refer to in plant biotechnology?
Permanent integration of a gene into the genome
Temporary expression of a gene without stable integration
Expression of genes only during seed germination
Expression that lasts for multiple generations
Explanation - Transient expression uses methods like agroinfiltration to produce proteins for a short period, useful for rapid testing.
Correct answer is: Temporary expression of a gene without stable integration
Q.35 The CRISPR system originally evolved in:
Plants
Bacteria
Fungi
Viruses
Explanation - CRISPR‑Cas is an adaptive immune system in bacteria and archaea, repurposed for genome editing.
Correct answer is: Bacteria
Q.36 Which method is used to increase the number of chromosomes in a diploid plant to produce a tetraploid?
Treating seedlings with colchicine
Applying high‑intensity light
Cross‑pollinating with a wild relative
Using Agrobacterium
Explanation - Colchicine disrupts spindle formation during mitosis, preventing chromosome segregation and doubling chromosome number.
Correct answer is: Treating seedlings with colchicine
Q.37 Which of the following best describes a 'knock‑in' strategy?
Removing a gene from the genome
Introducing a gene at a specific locus
Silencing a gene with RNAi
Increasing the copy number of a gene randomly
Explanation - Knock‑in inserts a DNA fragment precisely at a predetermined genomic location, often via homology‑directed repair.
Correct answer is: Introducing a gene at a specific locus
Q.38 What is the main advantage of using a 'stacked' trait in GM crops?
It reduces the size of the genome
It provides multiple benefits such as insect resistance and herbicide tolerance in one variety
It eliminates the need for pollinators
It makes the plant sterile
Explanation - Stacked traits combine two or more transgenes, giving farmers a single variety with several advantageous characteristics.
Correct answer is: It provides multiple benefits such as insect resistance and herbicide tolerance in one variety
Q.39 In the context of crop genetics, what is a 'donor parent'?
The plant that receives a gene
The plant providing a desirable gene in a cross
A plant that is sterile
A plant used only for seed production
Explanation - During breeding, the donor parent contributes the targeted allele that breeders aim to introgress into another line.
Correct answer is: The plant providing a desirable gene in a cross
Q.40 Which of the following crops has been engineered to produce a vaccine antigen (pharming)?
Rice
Potato
Tobacco
All of the above
Explanation - Plants like rice, potato, and tobacco have been used to express vaccine proteins, a concept known as molecular farming.
Correct answer is: All of the above
Q.41 What is the main purpose of a 'terminator' sequence in a transgene construct?
To stop transcription of the transgene
To promote gene duplication
To make the plant resistant to viruses
To enhance seed germination
Explanation - Terminator (poly‑A) sequences signal the end of transcription and help stabilize mRNA.
Correct answer is: To stop transcription of the transgene
Q.42 Which of the following is an example of a 'cis‑acting element'?
A transcription factor protein
A promoter region upstream of a gene
A ribosomal RNA molecule
A plasmid backbone
Explanation - Cis‑acting elements are DNA sequences that regulate the expression of nearby genes, such as promoters or enhancers.
Correct answer is: A promoter region upstream of a gene
Q.43 The term 'gene drive' in crop genetics refers to:
A system that increases the inheritance probability of a particular allele
A method to silence all genes in a plant
A way to double the number of chromosomes
A technique for measuring gene expression
Explanation - Gene drives bias inheritance so that a chosen trait spreads rapidly through a population, even if it confers no selective advantage.
Correct answer is: A system that increases the inheritance probability of a particular allele
Q.44 What is the primary role of 'Bt' toxin in genetically modified crops?
To increase chlorophyll content
To act as an insecticidal protein
To improve water use efficiency
To confer frost tolerance
Explanation - Bt toxins bind to gut receptors of certain insects, causing paralysis and death, thus protecting the plant.
Correct answer is: To act as an insecticidal protein
Q.45 Which of the following crops was the first to be approved for commercial cultivation using genome editing (CRISPR) without being classified as a GMO in the USA?
Soybean
Wheat
Mushroom
Tomato
Explanation - The CRISPR‑edited mushroom was deemed non‑GMO because no foreign DNA remained after editing.
Correct answer is: Mushroom
Q.46 What does the abbreviation 'RNAi' stand for?
Ribosomal Nucleic Acid interaction
RNA interference
Rapid Nucleotide Insertion
Regulatory Nucleotide Integration
Explanation - RNAi is a natural cellular mechanism where small RNAs guide the degradation of complementary mRNA, silencing gene expression.
Correct answer is: RNA interference
Q.47 Which breeding technique uses a backcross to introduce a single trait from a donor into an elite line?
Hybrid breeding
Recurrent selection
Marker‑assisted backcrossing
Synthetic population breeding
Explanation - MAS enables rapid recovery of the elite background while retaining the donor trait through successive backcrosses.
Correct answer is: Marker‑assisted backcrossing
Q.48 The term 'genome-wide association study' (GWAS) is used to:
Identify DNA sequences that code for proteins
Associate specific genetic markers with phenotypic traits across a population
Create transgenic plants
Measure gene expression levels
Explanation - GWAS scans many individuals to find statistical links between markers (e.g., SNPs) and traits like yield or disease resistance.
Correct answer is: Associate specific genetic markers with phenotypic traits across a population
Q.49 Which of the following is a major concern about the release of gene‑edited crops into the environment?
They will instantly increase global yields by 100 %
Potential unintended effects on non‑target organisms
They will become sterile and disappear
They will eradicate all weeds
Explanation - Gene‑edited crops could affect insects, soil microbes, or wild relatives if traits spread beyond intended fields.
Correct answer is: Potential unintended effects on non‑target organisms
Q.50 What is the purpose of the 'CaMV 35S promoter' commonly used in plant transformation vectors?
To drive strong, constitutive expression in most plant tissues
To silence the transgene
To make the plant resistant to viruses
To limit expression to root tissues only
Explanation - The cauliflower mosaic virus 35S promoter is a viral promoter that works in a wide range of plant species for high‑level expression.
Correct answer is: To drive strong, constitutive expression in most plant tissues
Q.51 In plant genetic engineering, what does the term 'stacked trait' refer to?
A single gene that controls multiple traits
Multiple transgenes inserted into one plant
A gene that is expressed only during seed development
A gene that is silenced by methylation
Explanation - Stacked traits combine several engineered characteristics (e.g., insect resistance + herbicide tolerance) in the same cultivar.
Correct answer is: Multiple transgenes inserted into one plant
Q.52 Which of the following crops has been successfully engineered for drought tolerance by over‑expressing the *DREB* transcription factor?
Rice
Maize
Wheat
All of the above
Explanation - DREB genes enhance abiotic stress responses, and transgenic lines of rice, maize, and wheat with DREB over‑expression show improved drought tolerance.
Correct answer is: All of the above
Q.53 A 'knock‑out' mutation in a plant gene typically results in:
Gain of function
Loss of function
Increased gene expression
No change in phenotype
Explanation - Knock‑out removes or disrupts a gene, eliminating its normal activity, which can reveal its role in the plant.
Correct answer is: Loss of function
Q.54 Which of the following is a major benefit of using double haploid (DH) technology in crop breeding?
It creates polyploid plants quickly
It accelerates the development of completely homozygous lines
It eliminates the need for seed production
It increases seed size
Explanation - DH plants are generated from haploid cells that double their chromosomes, producing fully homozygous individuals in a single generation.
Correct answer is: It accelerates the development of completely homozygous lines
Q.55 The gene *GmSALT3* introduced into soybean confers tolerance to:
Drought
High salinity
Cold temperatures
Insect pests
Explanation - *GmSALT3* encodes a transporter that helps maintain ion homeostasis under saline conditions.
Correct answer is: High salinity
Q.56 In plant biotechnology, what is a 'vector'?
A molecule that carries DNA into a cell
A type of soil nutrient
A protein that degrades RNA
A chromosome segment that controls flowering
Explanation - Vectors (plasmids, viruses) are engineered DNA molecules used to deliver transgenes into plant cells.
Correct answer is: A molecule that carries DNA into a cell
Q.57 Which of the following statements about 'cisgenesis' is true?
It introduces genes from bacteria into plants
It uses only genes from the same or closely related species
It always requires a selectable marker
It is synonymous with genome editing
Explanation - Cisgenesis avoids foreign DNA by using native plant genes, potentially simplifying regulatory pathways.
Correct answer is: It uses only genes from the same or closely related species
Q.58 Which of the following is a common selectable marker used in plant transformation?
Kanamycin resistance (NPTII)
Beta‑carotene synthesis
Drought tolerance gene
Photoperiod sensitivity gene
Explanation - The NPTII gene confers resistance to the antibiotic kanamycin, allowing selection of transformed cells on media containing the drug.
Correct answer is: Kanamycin resistance (NPTII)
Q.59 The use of 'gene editing' to delete the *ALS* gene in wheat results in:
Herbicide susceptibility
Herbicide resistance to sulfonylurea herbicides
Increased protein content
Early flowering
Explanation - Mutations in the *ALS* (acetolactate synthase) gene can render the enzyme insensitive to sulfonylurea herbicides.
Correct answer is: Herbicide resistance to sulfonylurea herbicides
Q.60 What does 'genome editing' NOT typically involve?
Introducing double‑strand breaks at specific sites
Using a donor DNA template for repair
Random integration of large DNA fragments
Designing guide RNAs for target specificity
Explanation - Genome editing aims for precise modifications; random integration is characteristic of traditional transformation, not targeted editing.
Correct answer is: Random integration of large DNA fragments
Q.61 Which of the following is a classic example of a 'quantitative trait' in crops?
Flower colour
Seed coat pattern
Grain yield per hectare
Leaf shape
Explanation - Quantitative traits are controlled by multiple genes and environment, such as yield, height, or drought tolerance.
Correct answer is: Grain yield per hectare
Q.62 What is the main function of the *Bar* gene in transgenic crops?
Provide resistance to the herbicide phosphinothricin (glufosinate)
Encode an insecticidal protein
Increase vitamin C content
Induce male sterility
Explanation - The *Bar* gene encodes phosphinothricin acetyltransferase, detoxifying the herbicide and allowing selective weed control.
Correct answer is: Provide resistance to the herbicide phosphinothricin (glufosinate)
Q.63 In a breeding program, the term 'recurrent selection' refers to:
Repeatedly crossing a plant with the same donor
Continuous selection of superior individuals over multiple cycles
Backcrossing to a recurrent parent
Using only self‑pollination
Explanation - Recurrent selection cycles improve population mean performance by repeatedly selecting and recombining the best individuals.
Correct answer is: Continuous selection of superior individuals over multiple cycles
Q.64 Which of the following crops has been edited to reduce the production of a natural toxin (e.g., cyanogenic glycosides) for food safety?
Cassava
Barley
Soybean
Cotton
Explanation - CRISPR editing of the *CYP79D1*/*CYP79D2* genes reduces cyanogenic glucoside content, making cassava safer to consume.
Correct answer is: Cassava
Q.65 The 'Golden Rice' project primarily uses genes from which organisms?
Bacteria and daffodil (Narcissus)
Fungi and wheat
Algae and rice itself
Animals and viruses
Explanation - Golden Rice contains *psy* (daffodil) and *crtI* (bacterial) genes to synthesize β‑carotene in the endosperm.
Correct answer is: Bacteria and daffodil (Narcissus)
Q.66 A 'gene drive' system in a crop could potentially be used for:
Rapidly spreading a disease‑resistance allele through wild populations
Increasing seed size by polyploidy
Eliminating all pests in a field
Improving photosynthetic efficiency without gene editing
Explanation - Gene drives bias inheritance so that a selected allele spreads quickly, which could be used to confer resistance in weeds or pests.
Correct answer is: Rapidly spreading a disease‑resistance allele through wild populations
Q.67 Which of the following is an example of a 'synthetic biology' approach in crop improvement?
Stacking multiple native resistance genes
Designing a novel metabolic pathway to produce a vitamin not normally found in the plant
Cross‑breeding two varieties
Applying fertilizer to increase yield
Explanation - Synthetic biology constructs new gene circuits or pathways, often introducing multiple genes to create novel functions.
Correct answer is: Designing a novel metabolic pathway to produce a vitamin not normally found in the plant
Q.68 Which plant organ is most commonly used for *Agrobacterium*-mediated transformation?
Root tips
Leaf discs
Seeds
Stems
Explanation - Leaf disc infection is a standard method for many dicot species; the tissue is co‑cultivated with *Agrobacterium* and then regenerated.
Correct answer is: Leaf discs
Q.69 What is the primary reason that many countries regulate GM crops based on the presence of foreign DNA?
Foreign DNA is always harmful
Regulations focus on the method of creation rather than the final product
Foreign DNA always increases allergenicity
Foreign DNA cannot be detected
Explanation - Many policies consider the technique (e.g., transgenesis) as a trigger for regulation, regardless of the trait's safety or benefit.
Correct answer is: Regulations focus on the method of creation rather than the final product
Q.70 Which of the following is a potential advantage of using CRISPR base editors over conventional CRISPR‑Cas9 nucleases?
They create double‑strand breaks
They can convert one nucleotide to another without cutting DNA
They insert large DNA fragments
They work only in animal cells
Explanation - Base editors fuse a deaminase to a catalytically impaired Cas protein, enabling precise base changes without double‑strand breaks.
Correct answer is: They can convert one nucleotide to another without cutting DNA
Q.71 The term 'polyploidy' is most commonly associated with which of the following crop improvements?
Increased disease susceptibility
Larger fruit size and vigor
Reduced seed germination
Lower protein content
Explanation - Polyploid plants often have larger cells and enhanced metabolic capacity, leading to bigger fruits and stronger growth.
Correct answer is: Larger fruit size and vigor
Q.72 In the context of genetic improvement, what does the abbreviation 'MAS' stand for?
Molecular Amplification System
Marker‑Assisted Selection
Mutagenic Antibody Synthesis
Metabolic Augmentation Strategy
Explanation - MAS utilizes DNA markers linked to desirable traits to select plants at the seedling stage, accelerating breeding cycles.
Correct answer is: Marker‑Assisted Selection
Q.73 Which of the following is a common use of the *NPTII* gene in plant transformation vectors?
Herbicide resistance
Antibiotic resistance for selection
Insect resistance
Drought tolerance
Explanation - *NPTII* confers resistance to kanamycin or G418, allowing transformed cells to be selected on media containing the antibiotic.
Correct answer is: Antibiotic resistance for selection
Q.74 What is the main advantage of using 'double haploid' technology in crop breeding?
Creates heterozygous plants quickly
Provides completely homozygous lines in a single generation
Increases the number of chromosomes
Eliminates the need for pollination
Explanation - Double haploids are derived from haploid cells that double their chromosome number, yielding fully homozygous individuals without several generations of selfing.
Correct answer is: Provides completely homozygous lines in a single generation
Q.75 The *Bt* Cry1Ab protein primarily targets which group of pests?
Nematodes
Lepidopteran insects (e.g., corn borer)
Aphids
Weevils
Explanation - Cry1Ab is toxic to many lepidopteran larvae, protecting crops like corn and cotton from these pests.
Correct answer is: Lepidopteran insects (e.g., corn borer)
Q.76 Which of the following is NOT a typical reason to create a transgenic crop?
Increase nutritional content
Improve tolerance to abiotic stress
Reduce the need for pesticide applications
Make the plant glow in the dark for aesthetic purposes
Explanation - While technically possible, aesthetic bioluminescence is not a primary agricultural objective; the other options address yield, nutrition, and sustainability.
Correct answer is: Make the plant glow in the dark for aesthetic purposes
Q.77 Which of the following best describes 'genomic selection'?
Selection based on visual traits only
Predicting breeding values using genome‑wide marker data
Selecting plants based on seed size alone
Choosing parents randomly
Explanation - Genomic selection uses dense marker data to estimate the genetic merit of individuals, enabling early selection without phenotyping.
Correct answer is: Predicting breeding values using genome‑wide marker data
Q.78 What is the main role of the *EPSPS* gene in glyphosate‑tolerant crops?
Encode a protein that degrades glyphosate
Encode a glyphosate‑insensitive version of the enzyme 5‑enolpyruvylshikimate‑3‑phosphate synthase
Produce a toxin that kills weeds
Increase photosynthetic efficiency
Explanation - Modified EPSPS continues the shikimate pathway even in the presence of glyphosate, allowing the plant to survive glyphosate applications.
Correct answer is: Encode a glyphosate‑insensitive version of the enzyme 5‑enolpyruvylshikimate‑3‑phosphate synthase
Q.79 Which technology allows precise insertion of a DNA fragment at a pre‑determined genomic locus using a repair template?
Non‑homologous end joining (NHEJ)
Homology‑directed repair (HDR)
RNA interference (RNAi)
Somatic embryogenesis
Explanation - HDR uses a donor template with homology arms to repair a CRISPR‑induced break, enabling precise gene insertion.
Correct answer is: Homology‑directed repair (HDR)
Q.80 The 'Mendelian inheritance' pattern is best described as:
Traits controlled by many genes and the environment
Traits determined by a single gene with dominant and recessive alleles
Traits that do not follow any predictable pattern
Traits that are only inherited through the mother
Explanation - Mendelian inheritance involves discrete traits segregating according to dominant/recessive allele patterns.
Correct answer is: Traits determined by a single gene with dominant and recessive alleles
Q.81 Which of the following is a widely used CRISPR‑Cas variant that recognizes a different PAM sequence, expanding target sites?
Cas9‑VQR
Cas12a (Cpf1)
Cas13a
Cas4
Explanation - Cas12a (Cpf1) requires a T-rich PAM (TTTV), allowing editing at sites inaccessible to SpCas9.
Correct answer is: Cas12a (Cpf1)
Q.82 In the context of crop biotechnology, 'biofortification' aims to:
Increase the size of the plant's root system
Introduce genes that make crops resistant to all pests
Enhance the nutritional content of edible parts
Make crops grow faster under any condition
Explanation - Biofortified crops are bred or engineered to contain higher levels of vitamins, minerals, or essential amino acids.
Correct answer is: Enhance the nutritional content of edible parts
Q.83 Which of the following is a major ethical concern associated with the release of gene‑edited crops?
The crops will become sentient
Unintended spread of edited traits to wild relatives
The crops will instantly solve world hunger
Gene‑edited crops cannot be cultivated
Explanation - Gene flow could transfer edited alleles to non‑target populations, potentially affecting ecosystems.
Correct answer is: Unintended spread of edited traits to wild relatives
Q.84 Which of the following is an example of a 'synthetic promoter' used in plant genetic engineering?
CaMV 35S
Ubiquitin promoter from maize
A custom-built sequence combining elements from several native promoters
Photosystem II promoter
Explanation - Synthetic promoters are engineered by assembling regulatory motifs to achieve desired expression patterns.
Correct answer is: A custom-built sequence combining elements from several native promoters
Q.85 What is the main purpose of 'gene stacking' in modern crop varieties?
To reduce the genome size
To combine multiple desirable traits into one plant
To make the plant sterile
To increase the plant's chromosome number
Explanation - Gene stacking merges several transgenes (e.g., insect resistance, herbicide tolerance) into a single cultivar for broader protection.
Correct answer is: To combine multiple desirable traits into one plant
Q.86 Which of the following crops has been successfully edited to increase its vitamin A content without using foreign DNA?
Maize
Wheat
Rice
Soybean
Explanation - CRISPR editing of endogenous carotenoid pathway genes in rice has boosted provitamin A levels without transgenes.
Correct answer is: Rice
Q.87 In plant transformation, the term 'co‑culture' refers to:
Growing plants together with insects
Incubating plant tissue with *Agrobacterium* before regeneration
Planting seeds in mixed soil types
Harvesting multiple crops at once
Explanation - Co‑culture is a step where plant explants are exposed to *Agrobacterium* to allow T‑DNA transfer before selection and regeneration.
Correct answer is: Incubating plant tissue with *Agrobacterium* before regeneration
Q.88 Which of the following is NOT a typical outcome of polyploidization in crops?
Increased cell size
Greater genetic redundancy
Reduced vigor
Potential for novel traits
Explanation - Polyploid plants often exhibit increased vigor (heterosis), larger cells, and may express new phenotypes, though some may face fertility issues.
Correct answer is: Reduced vigor
Q.89 What does the acronym 'CRISPR' stand for?
Clustered Regularly Interspaced Short Palindromic Repeats
Cytoplasmic RNA Interference System for Protein Regulation
Chromosomal Rearrangement Inducing System for Plant Regeneration
Catalytic RNA Integrated System for Protein Repair
Explanation - CRISPR refers to the bacterial adaptive immune system that has been adapted for genome editing.
Correct answer is: Clustered Regularly Interspaced Short Palindromic Repeats
Q.90 Which of the following traits can be improved by overexpressing the *DREB* transcription factor in crops?
Increased pest resistance
Enhanced drought and salt stress tolerance
Higher grain protein content
Earlier flowering
Explanation - DREB (dehydration‑responsive element‑binding) transcription factors regulate stress‑responsive genes, improving tolerance to abiotic stresses.
Correct answer is: Enhanced drought and salt stress tolerance
Q.91 In a breeding program, the term 'recurrent parent' refers to:
The plant that donates the trait of interest
The elite line repeatedly backcrossed to retain its background
A wild relative used for introgression
A plant used only for seed production
Explanation - The recurrent parent is repeatedly crossed with the donor to maintain most of its genome while incorporating the desired trait.
Correct answer is: The elite line repeatedly backcrossed to retain its background
Q.92 Which method can be used to produce non‑transgenic, edited plants by delivering CRISPR components as ribonucleoprotein (RNP) complexes?
Agrobacterium transformation
Particle bombardment with DNA plasmids
Protoplast transfection with Cas9‑sgRNA RNPs
Virus‑mediated RNA delivery
Explanation - Delivering Cas9 protein and guide RNA directly avoids DNA integration, yielding edited plants free of foreign DNA.
Correct answer is: Protoplast transfection with Cas9‑sgRNA RNPs
Q.93 What is the main function of the 'T-DNA' region in *Agrobacterium* vectors?
To encode the bacterium’s own replication machinery
To carry the gene(s) of interest into the plant genome
To provide resistance to antibiotics for the bacterium
To produce plant hormones
Explanation - During infection, the T‑DNA segment is transferred from the bacterium to the plant cell and becomes integrated into the plant genome.
Correct answer is: To carry the gene(s) of interest into the plant genome
Q.94 Which of the following crop traits is typically considered quantitative rather than qualitative?
Flower colour
Seed coat pattern
Grain yield per hectare
Leaf shape
Explanation - Yield is influenced by many genes and environmental factors, making it a quantitative trait.
Correct answer is: Grain yield per hectare
Q.95 In the context of plant genetic engineering, what does the term 'cis‑acting element' refer to?
A protein that binds DNA
A DNA sequence that regulates transcription of a nearby gene
A mobile genetic element that moves between chromosomes
An RNA molecule that degrades mRNA
Explanation - Cis‑acting elements such as promoters or enhancers are located on the same DNA molecule as the gene they regulate.
Correct answer is: A DNA sequence that regulates transcription of a nearby gene
Q.96 Which of the following is an example of a 'transgene' used for insect resistance?
Bt Cry1Ac
Bar
EPSPS
NPTII
Explanation - Cry1Ac is a Bt toxin protein that confers resistance against lepidopteran insects when expressed in plants.
Correct answer is: Bt Cry1Ac
Q.97 What is the main advantage of using a 'gene cassette' with multiple genes linked together in a vector?
It reduces the size of the vector
It allows simultaneous expression of several traits from a single transformation event
It prevents the vector from being transferred to other organisms
It makes the plant sterile
Explanation - A gene cassette can carry multiple functional units (promoter‑gene‑terminator) enabling stacked traits in one integration.
Correct answer is: It allows simultaneous expression of several traits from a single transformation event
Q.98 Which of the following crops has been engineered to produce a vaccine antigen for hepatitis B?
Potato
Rice
Tomato
All of the above
Explanation - Multiple plants, including potato, rice, and tomato, have been used as platforms to express hepatitis B surface antigen for edible vaccines.
Correct answer is: All of the above
Q.99 Which of the following statements best describes 'genome editing'?
Random insertion of large DNA fragments
Precise modification of specific DNA sequences
Only applicable to animal cells
A method to increase chromosome number
Explanation - Genome editing tools like CRISPR enable targeted changes (knock‑out, knock‑in, base editing) at chosen genomic sites.
Correct answer is: Precise modification of specific DNA sequences
Q.100 The 'Golden Rice' project was primarily intended to address which nutritional deficiency?
Iron deficiency
Vitamin A deficiency
Calcium deficiency
Omega‑3 fatty acid deficiency
Explanation - Golden Rice produces β‑carotene, a precursor of vitamin A, to combat deficiency in populations relying heavily on rice.
Correct answer is: Vitamin A deficiency