Biotechnology: Principles and Processes — Practice Questions with Answers

Q1.

Restriction enzymes are used to:

• A Join separate DNA fragments back together
• B Cut DNA at specific sequences
• C Copy DNA strands during replication
• D Translate mRNA into a protein chain

Q2.

PCR (Polymerase Chain Reaction) is used to:

• A Determine the exact sequence of bases in DNA
• B Amplify specific DNA sequences
• C Synthesize new proteins from an mRNA template
• D Deliberately create new mutations in target genes

Q3.

A plasmid is:

• A A viral DNA genome that is packaged tightly inside a protein capsid
• B Small circular extrachromosomal DNA in bacteria (used as vector)
• C A restriction enzyme that cuts DNA at specific recognition sites
• D A type of ribosome complex involved directly in protein translation

Q4.

Bt crops contain a gene from:

• A A plant virus engineered to confer general disease resistance
• B Bacillus thuringiensis bacteria (insect-resistant toxin)
• C A soil fungus known for producing natural antifungal compounds
• D A yeast strain commonly used in industrial fermentation processes

Q5.

Gel electrophoresis separates DNA fragments by:

• A Color visible under UV illumination
• B Size (smaller fragments travel farther)
• C Charge alone, independent of fragment size
• D Shape alone, independent of molecular weight

Q6.

The first product produced by recombinant DNA technology for medical use was:

• A Penicillin extracted from Penicillium mold
• B Human insulin (from E. coli)
• C Aspirin synthesized chemically from salicylic acid
• D Vitamin C produced by microbial fermentation

Q7.

ELISA test is used for:

• A Determining the order of nucleotide bases in DNA
• B Detection of antibodies or antigens (e.g., HIV test)
• C Culturing bacterial colonies on agar plates
• D Separating DNA fragments by molecular size

Q8.

A vector in genetic engineering is:

• A A type of organism that is itself the target of genetic modification
• B Carrier of foreign DNA into a host cell (e.g., plasmid or virus)
• C A restriction enzyme that simply cleaves the target DNA strand
• D A type of antibody used specifically in diagnostic laboratory assays

Q9.

Golden Rice is a transgenic crop that produces:

• A Higher levels of storage proteins in the grain
• B Vitamin A (beta-carotene) in grain
• C Resistance to insect pests via a bacterial toxin
• D Tolerance to herbicide spraying in the field

Q10.

The enzyme DNA ligase is used to:

• A Cut DNA at specific recognition sites
• B Join DNA fragments together
• C Amplify DNA exponentially through repeated cycles
• D Determine the nucleotide sequence of DNA

Q11.

CRISPR-Cas9 is a technology for:

• A Amplifying DNA through repeated thermal cycles
• B Gene editing (cutting specific DNA sequences)
• C Separating DNA fragments by size in a gel
• D Synthesizing proteins from an mRNA template

Q12.

Hybridoma technology is used to produce:

• A Transgenic plants
• B Monoclonal antibodies
• C Recombinant insulin
• D PCR products

Q13.

Sticky ends are produced when restriction enzymes make:

• A Blunt cuts straight across both DNA strands
• B Staggered cuts leaving single-stranded overhangs
• C Circular cuts that excise a closed DNA loop
• D Random cuts at unpredictable genomic positions

Q14.

Fermentation used in biotechnology means:

• A A process that typically yields ethanol as its most well-known end product according to standard textbooks
• B 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 practice
• D A process used mainly for producing wine, beer, and other alcoholic beverages as frequently described

Q15.

The polymerase chain reaction (PCR) requires which temperature to denature DNA?

• A 37 C
• B 55 C
• C 72 C
• D 94-95 C

Q16.

Taq polymerase is used in PCR because:

• A It is the cheapest enzyme available for routine laboratory use
• B It is thermostable (heat-resistant from Thermus aquaticus bacterium)
• C It has the highest proofreading fidelity of any known polymerase
• D It is the only DNA polymerase known to exist in bacteria

Q17.

In Southern blotting, which molecule is being detected?

• A RNA transcripts separated by gel electrophoresis
• B Protein bands detected using a labeled antibody probe
• C Specific DNA sequences
• D Lipids extracted and separated by thin-layer chromatography

Q18.

Agrobacterium tumefaciens is used in plant biotechnology because:

• A It fixes atmospheric nitrogen gas directly within specialized root nodule structures
• B 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 elongation
• D It confers natural drought resistance to any host plant it successfully infects

Q19.

The Cas9 protein in CRISPR is guided to its target by:

• A Protein-protein interactions with transcription factor complexes
• B Guide RNA (gRNA) complementary to the target DNA sequence
• C Restriction enzymes that recognize specific palindromic sequences
• D Diffusible chemical signals released by the target cell

Q20.

Tissue culture of plants relies on the concept of:

• A Genetic variability arising from random mutation occurring during tissue culture
• B Totipotency (each plant cell has the potential to develop into a whole organism)
• C Mainly vegetative reproduction occurring through stem cuttings and grafting
• D Clonal variation introduced deliberately during the subculturing process

Q21.

Which technique is used to diagnose genetic disorders prenatally?

• A PCR alone, performed directly on collected maternal blood plasma samples
• B Amniocentesis and chorionic villus sampling (CVS) -- fetal cells analyzed
• C ELISA alone, detecting maternal antibody levels in blood serum
• D Gel electrophoresis alone, run directly on maternal serum samples

Q22.

Somatic cell nuclear transfer (SCNT) was the technique used for:

• A Making the first GMO crop
• B Cloning Dolly the sheep
• C Producing monoclonal antibodies
• D Making recombinant insulin

Q23.

Recombinant DNA is made by:

• A Randomly mutating existing DNA using chemical mutagens
• B Cutting DNA with restriction enzymes and joining foreign DNA with ligase
• C Copying DNA exclusively through repeated PCR amplification cycles
• D Physically excising genes from chromosomes without replacement

Q24.

Gene expression can be analyzed across the entire genome using:

• A Southern blot
• B DNA microarray (gene chip)
• C PCR only
• D Gel electrophoresis

Q25.

Antisense technology uses:

• A Sense strand mRNA copies identical to the natural transcript
• B RNA complementary to mRNA to block translation of a specific gene
• C Foreign DNA directly injected into the nucleus of target cells
• D Restriction enzymes that physically cleave the target mRNA

Q26.

The Flavr Savr tomato was engineered to:

• A Resist insect pests through an introduced bacterial toxin gene from Bt
• B Resist herbicide application during routine field cultivation practices
• C Have delayed ripening and softening (antisense polygalacturonase)
• D Produce elevated levels of vitamin A within the ripened fruit tissue

Q27.

In forensic DNA profiling, which technique is used to analyze STR loci?

• A Southern blot hybridization using a radioactive DNA probe
• B PCR amplification followed by capillary electrophoresis
• C Northern blot hybridization to detect specific mRNA transcripts
• D Western blot detection using a labeled antibody probe

Q28.

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 researchers
• B It sequences millions of DNA fragments simultaneously in parallel (massively parallel sequencing), dramatically reducing cost and time
• C 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 studied
• D It is reported to be capable of sequencing mainly RNA molecules directly, and is said to rarely sequence genomic DNA as widely reported

Q29.

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 encountered
• B Precise conversion of one DNA base to another (e.g., C to T or A to G) without double-strand break, reducing off-target indels
• C Mainly large-scale chromosomal rearrangements, such as inversions and reciprocal translocations as frequently observed in practice
• D Editing that is restricted mainly to RNA transcripts, and rarely to genomic DNA itself directly in many documented cases

Q30.

ChIP-seq (Chromatin Immunoprecipitation-sequencing) identifies:

• A Point mutations scattered randomly across the entire genome of a particular cell line studied according to conventional understanding
• B 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 practice
• D Mainly the precise positions of methylated cytosine bases located within CpG island regions nearby overall in most cases

Q31.

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 accounts
• B Delivering mRNA encoding the viral spike protein; cells produce the antigen, generating immune response without infection
• C Injecting viral DNA that is designed to integrate permanently into the host cell genome directly during normal conditions
• D Using a bacterial DNA plasmid alone, without any lipid nanoparticle delivery system involved as generally observed in typical laboratory settings

Q32.

ATAC-seq reveals:

• A Quantitative mRNA expression levels that are generally averaged uniformly across an entire population of cells studied closely under usual circumstances
• B Genome-wide open chromatin regions (accessible, active regulatory elements) by transposase-accessible chromatin with high-throughput sequencing
• C Mainly the overall pattern of cytosine methylation occurring across the entire genome of the cell being studied closely according to most researchers
• D Mainly the precise genomic location of repetitive, transposon-derived DNA sequences scattered within the chromatin region in the majority of cases studied

Q33.

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 practice
• B Using a pegRNA + Cas9 nickase + reverse transcriptase to install any base change, small insertions or deletions without DSB and without a DNA donor template
• C 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 practice
• D Working mainly on C to T base conversions, much like standard first-generation base editing tools generally in many documented cases according to conventional understanding

Q34.

Biosafety level 4 (BSL-4) laboratories are required for:

• A Routine, everyday research involving common, non-pathogenic laboratory bacterial strains generally used in routine practice
• B Work with dangerous pathogens with no treatment or vaccine (Ebola, Marburg, Nipah virus) that are transmitted by aerosol
• C Work that is limited mainly to the handling of hazardous laboratory chemical reagents in storage overall in most cases
• D Culturing of mostly non-pathogenic fungal species for routine taxonomic study purposes generally under typical conditions

Q35.

Antibody-drug conjugates (ADCs) are cancer drugs that:

• A Consist of plain, largely unmodified antibodies with little attached cytotoxic drug payload present during normal conditions
• B Link a monoclonal antibody (targeting tumor antigen) to a cytotoxic drug, delivering the drug selectively to cancer cells
• C Are DNA-based therapeutic constructs delivered directly into the nucleus of the tumor cell itself as generally observed
• D Are small-molecule drugs alone, used mainly without any antibody-based targeting component included in typical laboratory settings

Q36.

Single-cell RNA sequencing (scRNA-seq) enables:

• A Calculating a single averaged gene expression value across an entire bulk tissue sample collected
• B Gene expression profiling of individual cells, revealing cellular heterogeneity and cell types within tissues
• C Analysis that is restricted mainly to bulk tissue homogenates, and rarely individual single cells directly
• D Profiling restricted mainly to overall protein expression levels, rather than mRNA transcript abundance

Q37.

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 time
• B 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 structure
• D They actively kill the target cells that they successfully infect during the gene delivery process

Q38.

Allele-specific oligonucleotide (ASO) hybridization diagnoses:

• A Mainly large-scale chromosomal rearrangements, such as inversions and reciprocal translocations between non-homologous chromosomes
• B Single base mutations in specific genes (e.g., sickle cell, cystic fibrosis) by differential hybridization under stringent conditions
• C Mainly large, multi-exon gene deletions that are readily and easily detectable using ordinary standard PCR techniques
• D Mainly the mere presence of foreign viral DNA sequences that have become integrated within the host cell genome

Q39.

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 researchers
• B Engineering a patient T cells to express synthetic receptors recognizing tumor antigens, bypassing normal T cell activation requirements
• C Using free-floating monoclonal antibody molecules alone, with few engineered T cells involved generally in the majority of cases studied
• D Eliminating most of the patient existing immune cells before replacing them with new ones afterward as widely reported in standard practice

Q40.

AlphaFold (DeepMind) achievement in biotechnology was:

• A Sequencing the very first complete bacterial genome using classical Sanger sequencing chemistry methods in general practice
• B Solving the protein folding problem by accurately predicting 3D protein structure from amino acid sequence using deep learning
• C Performing the first successful gene editing experiment ever carried out using CRISPR-Cas9 technology as frequently described
• D Producing the very first monoclonal antibody using classical hybridoma fusion technology methods in most textbook accounts

Q41.

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 conditions
• B The balance between desired gene editing at the intended site vs. unintended cuts at similar sequences elsewhere in the genome
• C A measure that reflects mainly the physical size of the double-strand break that was created nearby as generally observed
• D A measure that reflects mainly the total length of the guide RNA used in the experiment conducted in typical laboratory settings