🔬 Biology · Class 12 · NEET
Biotechnology: Principles and Processes - Practice Questions with Answers 75 free MCQs on Biotechnology: Principles and Processes, each with its own worked answer and explanation. Recombinant DNA, GMOs, PCR, CRISPR, and biotechnology applications. Growing importance in NEET.
Take the timed Biotechnology: Principles and Processes chapterwise test → 75 practice questions on Biotechnology: Principles and Processes , sorted Easy → Hard. Try each one first, then open its answer page for the worked explanation. Want the full theory first? Read the Biotechnology: Principles and Processes notes .
Plasmid Gene of interest cut restriction enzyme ligate Recombinant plasmid Host cell Recombinant DNA technology: a gene of interest and plasmid are cut by the same restriction enzyme, ligated into a recombinant plasmid, and introduced into a host cell.
Easy - 25 questions Q1.
The restriction enzyme EcoRI was isolated from which organism?
A Escherichia coliB Bacillus amyloliquefaciensC Haemophilus influenzaeD Thermus aquaticusShow answer & explanation →
Q2.
In the name of a restriction enzyme like EcoRI, the first letter is derived from the:
A Species nameB Genus nameC Strain numberD Roman numeral orderShow answer & explanation →
Q3.
Which of the following is used to make the bacterial cell wall competent to take up DNA in transformation?
A Glucose solutionB Distilled waterC Divalent calcium ionsD Sodium chloride crystalsShow answer & explanation →
Q4.
Palindromic sequences that are recognised by restriction enzymes read the same:
A When read in one direction along a single strand onlyB On the same strand twiceC Only after being cutD In the same orientation on both strands when read 5 to 3Show answer & explanation →
Q5.
The cutting of DNA by restriction endonucleases followed by separation of fragments is visualised using:
A Gel electrophoresisB PCRC AutoclavingD CentrifugationShow answer & explanation →
Q6.
Restriction enzymes are used to:
A Join separate DNA fragments back togetherB Cut DNA at specific sequencesC Copy DNA strands during replicationD Translate mRNA into a protein chainShow answer & explanation →
Q7.
PCR (Polymerase Chain Reaction) is used to:
A Determine the exact sequence of bases in DNAB Amplify specific DNA sequencesC Synthesize new proteins from an mRNA templateD Deliberately create new mutations in target genesShow answer & explanation →
Q8.
A plasmid is:
A A viral DNA genome that is packaged tightly inside a protein capsidB Small circular extrachromosomal DNA in bacteria (used as vector)C A restriction enzyme that cuts DNA at specific recognition sitesD A type of ribosome complex involved directly in protein translationShow answer & explanation →
Q9.
Bt crops contain a gene from:
A A plant virus engineered to confer general disease resistanceB Bacillus thuringiensis bacteria (insect-resistant toxin)C A soil fungus known for producing natural antifungal compoundsD A yeast strain commonly used in industrial fermentation processesShow answer & explanation →
Q10.
Gel electrophoresis separates DNA fragments by:
A Color visible under UV illuminationB Size (smaller fragments travel farther)C Charge alone, independent of fragment sizeD Shape alone, independent of molecular weightShow answer & explanation →
Q11.
The first product produced by recombinant DNA technology for medical use was:
A Penicillin extracted from Penicillium moldB Human insulin (from E. coli)C Aspirin synthesized chemically from salicylic acidD Vitamin C produced by microbial fermentationShow answer & explanation →
Q12.
ELISA test is used for:
A Determining the order of nucleotide bases in DNAB Detection of antibodies or antigens (e.g., HIV test)C Culturing bacterial colonies on agar platesD Separating DNA fragments by molecular sizeShow answer & explanation →
Q13.
A vector in genetic engineering is:
A A type of organism that is itself the target of genetic modificationB Carrier of foreign DNA into a host cell (e.g., plasmid or virus)C A restriction enzyme that simply cleaves the target DNA strandD A type of antibody used specifically in diagnostic laboratory assaysShow answer & explanation →
Q14.
Golden Rice is a transgenic crop that produces:
A Higher levels of storage proteins in the grainB Vitamin A (beta-carotene) in grainC Resistance to insect pests via a bacterial toxinD Tolerance to herbicide spraying in the fieldShow answer & explanation →
Q15.
The enzyme DNA ligase is used to:
A Cut DNA at specific recognition sitesB Join DNA fragments togetherC Amplify DNA exponentially through repeated cyclesD Determine the nucleotide sequence of DNAShow answer & explanation →
Q16.
CRISPR-Cas9 is a technology for:
A Amplifying DNA through repeated thermal cyclesB Gene editing (cutting specific DNA sequences)C Separating DNA fragments by size in a gelD Synthesizing proteins from an mRNA templateShow answer & explanation →
Q17.
Hybridoma technology is used to produce:
A Transgenic plantsB Monoclonal antibodiesC Recombinant insulinD PCR productsShow answer & explanation →
Q18.
Sticky ends are produced when restriction enzymes make:
A Blunt cuts straight across both DNA strandsB Staggered cuts leaving single-stranded overhangsC Circular cuts that excise a closed DNA loopD Random cuts at unpredictable genomic positionsShow answer & explanation →
Q19.
Fermentation used in biotechnology means:
A A process that typically yields ethanol as its most well-known end product according to standard textbooksB Microbial or enzymatic conversion of organic compounds (can produce medicines, food, etc.)C A process largely restricted to large-scale food and dairy manufacturing in general practiceD A process used mainly for producing wine, beer, and other alcoholic beverages as frequently describedShow answer & explanation →
Q21.
Which enzyme joins two DNA fragments?
A DNA ligaseB the DNA polymeraseC only a helicaseD a restriction oneShow answer & explanation →
Q25.
Which organism is a common host for cloning?
A E. coliB the human cellsC only a plant leafD a virus shellShow answer & explanation →
Medium - 25 questions Q26.
During gel electrophoresis the separated DNA bands cannot be seen directly. They are visualised by staining with a dye and then exposing the gel to:
A Infrared lightB UV radiationC X-raysD Visible white light onlyShow answer & explanation →
Q27.
The separated DNA bands are cut out from the gel and extracted from the gel piece in a process known as:
A BlottingB LigationC ElutionD AnnealingShow answer & explanation →
Q28.
A good cloning vector must have an origin of replication (ori). What is the role of this sequence?
A It codes for a selectable markerB It binds the ribosome to start translation of the geneC It cuts the DNA at specific sitesD It controls copy number and initiates replicationShow answer & explanation →
Q29.
In the plasmid pBR322, insertion of foreign DNA into the tetracycline-resistance gene inactivates it. This loss of a trait used to detect recombinants is called:
A Insertional inactivationB Genetic transformationC TransductionD ConjugationShow answer & explanation →
Q30.
A bioreactor differs from a simple flask culture mainly because it can:
A Grow only a few cells at a timeB Process large volumes under controlled conditionsC Work without any oxygen supplyD Avoid the need for any culture medium or nutrientsShow answer & explanation →
Q31.
The polymerase chain reaction (PCR) requires which temperature to denature DNA?
A 37 CB 55 CC 72 CD 94-95 CShow answer & explanation →
Q32.
Taq polymerase is used in PCR because:
A It is the cheapest enzyme available for routine laboratory useB It is thermostable (heat-resistant from Thermus aquaticus bacterium)C It has the highest proofreading fidelity of any known polymeraseD It is the only DNA polymerase known to exist in bacteriaShow answer & explanation →
Q33.
In Southern blotting, which molecule is being detected?
A RNA transcripts separated by gel electrophoresisB Protein bands detected using a labeled antibody probeC Specific DNA sequencesD Lipids extracted and separated by thin-layer chromatographyShow answer & explanation →
Q34.
Agrobacterium tumefaciens is used in plant biotechnology because:
A It fixes atmospheric nitrogen gas directly within specialized root nodule structuresB Its Ti plasmid naturally transfers T-DNA into plant genome (used to insert transgenes)C It produces plant growth hormones that specifically stimulate rapid shoot elongationD It confers natural drought resistance to any host plant it successfully infectsShow answer & explanation →
Q35.
The Cas9 protein in CRISPR is guided to its target by:
A Protein-protein interactions with transcription factor complexesB Guide RNA (gRNA) complementary to the target DNA sequenceC Restriction enzymes that recognize specific palindromic sequencesD Diffusible chemical signals released by the target cellShow answer & explanation →
Q36.
Tissue culture of plants relies on the concept of:
A Genetic variability arising from random mutation occurring during tissue cultureB Totipotency (each plant cell has the potential to develop into a whole organism)C Mainly vegetative reproduction occurring through stem cuttings and graftingD Clonal variation introduced deliberately during the subculturing processShow answer & explanation →
Q37.
Which technique is used to diagnose genetic disorders prenatally?
A PCR alone, performed directly on collected maternal blood plasma samplesB Amniocentesis and chorionic villus sampling (CVS) -- fetal cells analyzedC ELISA alone, detecting maternal antibody levels in blood serumD Gel electrophoresis alone, run directly on maternal serum samplesShow answer & explanation →
Q38.
Somatic cell nuclear transfer (SCNT) was the technique used for:
A Making the first GMO cropB Cloning Dolly the sheepC Producing monoclonal antibodiesD Making recombinant insulinShow answer & explanation →
Q39.
Recombinant DNA is made by:
A Randomly mutating existing DNA using chemical mutagensB Cutting DNA with restriction enzymes and joining foreign DNA with ligaseC Copying DNA exclusively through repeated PCR amplification cyclesD Physically excising genes from chromosomes without replacementShow answer & explanation →
Q40.
Gene expression can be analyzed across the entire genome using:
A Southern blotB DNA microarray (gene chip)C PCR onlyD Gel electrophoresisShow answer & explanation →
Q41.
Antisense technology uses:
A Sense strand mRNA copies identical to the natural transcriptB RNA complementary to mRNA to block translation of a specific geneC Foreign DNA directly injected into the nucleus of target cellsD Restriction enzymes that physically cleave the target mRNAShow answer & explanation →
Q42.
The Flavr Savr tomato was engineered to:
A Resist insect pests through an introduced bacterial toxin gene from BtB Resist herbicide application during routine field cultivation practicesC Have delayed ripening and softening (antisense polygalacturonase)D Produce elevated levels of vitamin A within the ripened fruit tissueShow answer & explanation →
Q43.
In forensic DNA profiling, which technique is used to analyze STR loci?
A Southern blot hybridization using a radioactive DNA probeB PCR amplification followed by capillary electrophoresisC Northern blot hybridization to detect specific mRNA transcriptsD Western blot detection using a labeled antibody probeShow answer & explanation →
Q44.
What does the enzyme EcoRI recognise on DNA?
A Palindrome sequenceB a random long codon siteC only a start codonD the AUG tripletShow answer & explanation →
Q45.
Sticky ends are produced by which class of enzymes?
A Restriction enzymesB the DNA polymerasesC only ligase typesD a helicase groupShow answer & explanation →
Q46.
Which process introduces recombinant DNA into bacteria?
A TransformationB the transduction wayC only translationD a translocationShow answer & explanation →
Q47.
In PCR, which enzyme extends the primers?
A Taq polymeraseB the DNA ligase usedC only a restrictionD a helicase enzymeShow answer & explanation →
Q48.
Selectable markers in a vector help to?
A Identify transformantsB the cutting of DNA siteC only join fragmentsD a copy the plasmidShow answer & explanation →
Q49.
Which vessel is used for large-scale culture of cells?
A BioreactorB the test tube onlyC only a petri dishD a glass beakerShow answer & explanation →
Q50.
The ori site in a plasmid is responsible for?
A Replication startB the antibiotic roleC only DNA cuttingD a marker functionShow answer & explanation →
Hard - 25 questions Q51.
Selection of recombinants by insertional inactivation of antibiotic markers is cumbersome. An alternative uses a gene coding for an enzyme that, when intact, cleaves a chromogenic substrate. This selection works because:
A Recombinant colonies produce a coloured productB Non-recombinant colonies fail to growC Recombinant colonies do not produce colourD Both colony types appear identicalShow answer & explanation →
Q52.
In the PCR cycle, the step of annealing requires the temperature to be lowered after denaturation. What happens during annealing?
A The two DNA strands separateB The DNA is permanently denaturedC Taq polymerase synthesises entirely new DNA strandsD Primers bind to the complementary single strandsShow answer & explanation →
Q53.
Agrobacterium tumefaciens is widely used to deliver genes into plant cells because in nature it:
A Transfers a piece of its Ti plasmid DNA into the plantB Injects its whole genome into the plant nucleusC Produces spores inside plant cellsD Fixes nitrogen in the plant rootsShow answer & explanation →
Q54.
After a recombinant protein is produced in a bioreactor, it must undergo downstream processing before marketing. This stage involves:
A Inserting the gene into the vectorB Separation, purification and formulation of the productC Cutting the DNA with specific restriction enzymesD Amplifying the gene by PCRShow answer & explanation →
Q55.
Blunt-ended DNA fragments produced by some restriction enzymes are harder to ligate than sticky ends. Why are sticky ends easier to join?
A They have no phosphate groupsB They are always much longer DNA fragments than blunt ends and bind far fasterC Their short single-stranded overhangs form hydrogen bonds with complementary endsD They do not need DNA ligaseShow answer & explanation →
Q56.
Next-generation sequencing (NGS) differs from Sanger sequencing in:
A It is reported to be limited mainly to sequencing very short DNA reads under fifty base pairs in length generally according to most researchersB It sequences millions of DNA fragments simultaneously in parallel (massively parallel sequencing), dramatically reducing cost and timeC It is said to largely reduce the need for any PCR amplification step to be performed beforehand on the sample in the majority of cases studiedD It is reported to be capable of sequencing mainly RNA molecules directly, and is said to rarely sequence genomic DNA as widely reportedShow answer & explanation →
Q57.
CRISPR base editing allows:
A Mainly the complete physical deletion of an entire target gene from the genome each time in standard practice under most conditions encounteredB Precise conversion of one DNA base to another (e.g., C to T or A to G) without double-strand break, reducing off-target indelsC Mainly large-scale chromosomal rearrangements, such as inversions and reciprocal translocations as frequently observed in practiceD Editing that is restricted mainly to RNA transcripts, and rarely to genomic DNA itself directly in many documented casesShow answer & explanation →
Q58.
ChIP-seq (Chromatin Immunoprecipitation-sequencing) identifies:
A Point mutations scattered randomly across the entire genome of a particular cell line studied according to conventional understandingB Genome-wide protein-DNA interactions and histone modifications (where transcription factors bind, which regions are active)C Overall mRNA expression patterns averaged uniformly across an entire bulk tissue sample collected in routine practiceD Mainly the precise positions of methylated cytosine bases located within CpG island regions nearby overall in most casesShow answer & explanation →
Q59.
mRNA vaccines against COVID-19 work by:
A Injecting a killed, largely inactivated form of the entire intact virus particle each time as frequently described in most textbook accountsB Delivering mRNA encoding the viral spike protein; cells produce the antigen, generating immune response without infectionC Injecting viral DNA that is designed to integrate permanently into the host cell genome directly during normal conditionsD Using a bacterial DNA plasmid alone, without any lipid nanoparticle delivery system involved as generally observed in typical laboratory settingsShow answer & explanation →
Q60.
ATAC-seq reveals:
A Quantitative mRNA expression levels that are generally averaged uniformly across an entire population of cells studied closely under usual circumstancesB Genome-wide open chromatin regions (accessible, active regulatory elements) by transposase-accessible chromatin with high-throughput sequencingC Mainly the overall pattern of cytosine methylation occurring across the entire genome of the cell being studied closely according to most researchersD Mainly the precise genomic location of repetitive, transposon-derived DNA sequences scattered within the chromatin region in the majority of cases studiedShow answer & explanation →
Q61.
The CRISPR prime editing system (Liu lab, 2019) improves upon base editing by:
A Generally using somewhat longer guide RNA molecules in order to improve overall on-target editing specificity each time as widely reported in standard practiceB Using a pegRNA + Cas9 nickase + reverse transcriptase to install any base change, small insertions or deletions without DSB and without a DNA donor templateC Requiring an exogenous DNA donor template to be supplied alongside most genome edit that is made consistently under most conditions encountered as frequently observed in practiceD Working mainly on C to T base conversions, much like standard first-generation base editing tools generally in many documented cases according to conventional understandingShow answer & explanation →
Q62.
Biosafety level 4 (BSL-4) laboratories are required for:
A Routine, everyday research involving common, non-pathogenic laboratory bacterial strains generally used in routine practiceB Work with dangerous pathogens with no treatment or vaccine (Ebola, Marburg, Nipah virus) that are transmitted by aerosolC Work that is limited mainly to the handling of hazardous laboratory chemical reagents in storage overall in most casesD Culturing of mostly non-pathogenic fungal species for routine taxonomic study purposes generally under typical conditionsShow answer & explanation →
Q63.
Antibody-drug conjugates (ADCs) are cancer drugs that:
A Consist of plain, largely unmodified antibodies with little attached cytotoxic drug payload present during normal conditionsB Link a monoclonal antibody (targeting tumor antigen) to a cytotoxic drug, delivering the drug selectively to cancer cellsC Are DNA-based therapeutic constructs delivered directly into the nucleus of the tumor cell itself as generally observedD Are small-molecule drugs alone, used mainly without any antibody-based targeting component included in typical laboratory settingsShow answer & explanation →
Q64.
Single-cell RNA sequencing (scRNA-seq) enables:
A Calculating a single averaged gene expression value across an entire bulk tissue sample collectedB Gene expression profiling of individual cells, revealing cellular heterogeneity and cell types within tissuesC Analysis that is restricted mainly to bulk tissue homogenates, and rarely individual single cells directlyD Profiling restricted mainly to overall protein expression levels, rather than mRNA transcript abundanceShow answer & explanation →
Q65.
Recombinant adeno-associated virus (rAAV) vectors used in gene therapy are favored because:
A They integrate randomly and quite frequently into the genome of the host cell over timeB They can infect non-dividing cells, have low immunogenicity, and do not typically integrate (episomal expression)C They are notably capable of carrying unusually large transgene inserts within their viral capsid structureD They actively kill the target cells that they successfully infect during the gene delivery processShow answer & explanation →
Q66.
Allele-specific oligonucleotide (ASO) hybridization diagnoses:
A Mainly large-scale chromosomal rearrangements, such as inversions and reciprocal translocations between non-homologous chromosomesB Single base mutations in specific genes (e.g., sickle cell, cystic fibrosis) by differential hybridization under stringent conditionsC Mainly large, multi-exon gene deletions that are readily and easily detectable using ordinary standard PCR techniquesD Mainly the mere presence of foreign viral DNA sequences that have become integrated within the host cell genomeShow answer & explanation →
Q67.
Chimeric antigen receptor T (CAR-T) cell therapy works by:
A Injecting generic, largely unmodified donor T cells without much prior genetic engineering performed under usual circumstances according to most researchersB Engineering a patient T cells to express synthetic receptors recognizing tumor antigens, bypassing normal T cell activation requirementsC Using free-floating monoclonal antibody molecules alone, with few engineered T cells involved generally in the majority of cases studiedD Eliminating most of the patient existing immune cells before replacing them with new ones afterward as widely reported in standard practiceShow answer & explanation →
Q68.
AlphaFold (DeepMind) achievement in biotechnology was:
A Sequencing the very first complete bacterial genome using classical Sanger sequencing chemistry methods in general practiceB Solving the protein folding problem by accurately predicting 3D protein structure from amino acid sequence using deep learningC Performing the first successful gene editing experiment ever carried out using CRISPR-Cas9 technology as frequently describedD Producing the very first monoclonal antibody using classical hybridoma fusion technology methods in most textbook accountsShow answer & explanation →
Q69.
On-target efficiency vs off-target effects in CRISPR represent:
A Two largely different names that generally describe the exact same underlying phenomenon observed during normal conditionsB The balance between desired gene editing at the intended site vs. unintended cuts at similar sequences elsewhere in the genomeC A measure that reflects mainly the physical size of the double-strand break that was created nearby as generally observedD A measure that reflects mainly the total length of the guide RNA used in the experiment conducted in typical laboratory settingsShow answer & explanation →
Q70.
Which method uses a gene gun to insert DNA?
A BiolisticsB the microinjectionC only electroporationD a transformationShow answer & explanation →
Q71.
Ligating an insert into a plasmid needs matching?
A Sticky endsB the blunt long endsC only the promotersD a marker regionsShow answer & explanation →
Q72.
Which bacterium is a natural genetic engineer of plants?
A AgrobacteriumB the E. coli strainC only Bacillus oneD a Rhizobium typeShow answer & explanation →
Q73.
During electrophoresis, DNA migrates toward which pole?
A AnodeB the cathode sideC only the middleD a neutral zoneShow answer & explanation →
Q74.
Downstream processing in biotechnology refers to?
A Product recoveryB the gene insertionC only DNA cuttingD a culture setupShow answer & explanation →
Q75.
The disarmed Ti plasmid is obtained from which organism?
A AgrobacteriumB the Bacillus typeC only Thermus oneD a Rhizobium spShow answer & explanation →