Q.1 Which of the following enzymes is commonly used to cut DNA at specific sequences?
DNA ligase
Restriction endonuclease
RNA polymerase
DNA polymerase
Explanation - Restriction endonucleases recognize specific DNA sequences and cut at those sites, which is essential in genetic engineering.
Correct answer is: Restriction endonuclease
Q.2 Which vector is most commonly used for introducing foreign DNA into bacterial cells?
Plasmid
Virus
Mitochondrion
Ribosome
Explanation - Plasmids are small circular DNA molecules used as vectors to carry foreign genes into bacterial cells.
Correct answer is: Plasmid
Q.3 What is the main purpose of PCR (Polymerase Chain Reaction)?
Protein synthesis
DNA amplification
RNA splicing
Gene silencing
Explanation - PCR is used to make millions of copies of a specific DNA segment for analysis or cloning.
Correct answer is: DNA amplification
Q.4 Which of the following organisms is commonly used in the production of human insulin?
Saccharomyces cerevisiae
Escherichia coli
Bacillus subtilis
Streptococcus pyogenes
Explanation - Genetically engineered E. coli bacteria can produce human insulin efficiently for medical use.
Correct answer is: Escherichia coli
Q.5 Which term describes an organism that has been genetically modified by inserting foreign DNA?
Mutant organism
Transgenic organism
Hybrid organism
Cloned organism
Explanation - A transgenic organism carries one or more genes from another species in its genome.
Correct answer is: Transgenic organism
Q.6 Which of the following techniques is used to separate DNA fragments based on size?
Gel electrophoresis
Chromatography
Spectrophotometry
Centrifugation
Explanation - DNA fragments are separated in a gel matrix under an electric field, with smaller fragments moving faster.
Correct answer is: Gel electrophoresis
Q.7 Which of the following is a common method of producing genetically identical plants?
Hybridization
Tissue culture
Transcription
CRISPR-Cas9 editing
Explanation - Plant tissue culture allows cloning of plants from small tissue samples under sterile conditions.
Correct answer is: Tissue culture
Q.8 In recombinant DNA technology, which enzyme joins DNA fragments together?
DNA polymerase
DNA ligase
Reverse transcriptase
Topoisomerase
Explanation - DNA ligase forms phosphodiester bonds between DNA fragments to create continuous strands.
Correct answer is: DNA ligase
Q.9 Which genetic engineering tool allows precise editing of specific DNA sequences in organisms?
CRISPR-Cas9
RNAi
Southern blotting
Gel electrophoresis
Explanation - CRISPR-Cas9 uses a guide RNA and Cas9 enzyme to target and cut specific DNA sequences for editing.
Correct answer is: CRISPR-Cas9
Q.10 What is the purpose of a selectable marker in a plasmid vector?
To cut DNA at specific sites
To identify cells that have taken up the plasmid
To amplify DNA
To transcribe RNA
Explanation - Selectable markers, such as antibiotic resistance genes, help identify successfully transformed cells.
Correct answer is: To identify cells that have taken up the plasmid
Q.11 Which type of RNA carries amino acids to the ribosome during protein synthesis?
mRNA
tRNA
rRNA
siRNA
Explanation - tRNA transports specific amino acids to the ribosome for assembly into proteins.
Correct answer is: tRNA
Q.12 Which term refers to the technique of introducing a gene from one species into another?
Gene cloning
Gene therapy
Genetic transformation
DNA fingerprinting
Explanation - Genetic transformation involves the incorporation of foreign DNA into a host organism's genome.
Correct answer is: Genetic transformation
Q.13 Which of the following is a practical application of biotechnology in agriculture?
Creating herbicide-resistant crops
Producing antibiotics
Gene therapy in humans
Protein electrophoresis
Explanation - Genetically engineered crops can be modified to resist pests or herbicides, improving yield.
Correct answer is: Creating herbicide-resistant crops
Q.14 Which technique is used to detect specific DNA sequences in a sample?
Southern blotting
Northern blotting
Western blotting
ELISA
Explanation - Southern blotting uses DNA probes to identify specific DNA sequences among fragments separated by gel electrophoresis.
Correct answer is: Southern blotting
Q.15 Which of the following is a common application of genetically engineered bacteria in industry?
Producing insulin
Making biodegradable plastics
Bioremediation
All of the above
Explanation - Genetically engineered bacteria are used in pharmaceuticals, bioplastics production, and environmental cleanup.
Correct answer is: All of the above
Q.16 Which method allows the amplification of RNA sequences?
RT-PCR
PCR
Western blotting
DNA sequencing
Explanation - Reverse transcription PCR (RT-PCR) converts RNA into complementary DNA before amplification.
Correct answer is: RT-PCR
Q.17 Which of the following is true about plasmids used in genetic engineering?
They are linear DNA molecules
They replicate independently of chromosomal DNA
They always carry harmful genes
They cannot carry foreign DNA
Explanation - Plasmids are circular DNA molecules that can replicate independently, making them ideal vectors for cloning genes.
Correct answer is: They replicate independently of chromosomal DNA
Q.18 Which type of cloning produces a genetically identical organism from a somatic cell?
Reproductive cloning
Therapeutic cloning
Gene cloning
Molecular cloning
Explanation - Reproductive cloning involves creating a new organism that is genetically identical to the donor organism.
Correct answer is: Reproductive cloning
Q.19 Which of the following is used to silence specific genes post-transcriptionally?
siRNA
tRNA
mRNA
rRNA
Explanation - Small interfering RNA (siRNA) binds to mRNA and promotes its degradation, preventing protein synthesis.
Correct answer is: siRNA
Q.20 Golden Rice has been genetically engineered to produce:
Vitamin A
Vitamin B12
Iron
Calcium
Explanation - Golden Rice is engineered to produce beta-carotene, a precursor of vitamin A, to address deficiency in humans.
Correct answer is: Vitamin A
Q.21 Which of the following is an example of gene therapy?
Inserting a functional gene to treat a genetic disorder
Using PCR to amplify DNA
Cloning a plant through tissue culture
Producing insulin in bacteria
Explanation - Gene therapy introduces functional genes into patients to correct or replace defective genes.
Correct answer is: Inserting a functional gene to treat a genetic disorder
Q.22 Which method is used to sequence DNA by incorporating chain-terminating nucleotides?
Sanger sequencing
Next-generation sequencing
RT-PCR
Northern blotting
Explanation - Sanger sequencing uses dideoxynucleotides to terminate DNA synthesis at specific bases, allowing sequence determination.
Correct answer is: Sanger sequencing
Q.23 Bt cotton is genetically modified to:
Resist insects
Increase drought tolerance
Produce more vitamins
Fix nitrogen
Explanation - Bt cotton expresses a bacterial gene that produces a toxin harmful to specific insect pests, reducing the need for pesticides.
Correct answer is: Resist insects
Q.24 Which of the following is true about recombinant DNA technology?
It allows insertion of foreign DNA into a host organism
It only works in plants
It cannot be used for therapeutic purposes
It was discovered in the 21st century
Explanation - Recombinant DNA technology enables the combination of DNA from different sources into a host for research, industrial, or therapeutic purposes.
Correct answer is: It allows insertion of foreign DNA into a host organism
Q.25 Which of the following is NOT a potential application of biotechnology?
Medicine development
Agricultural improvement
Environmental cleanup
Astrophysical calculations
Explanation - Biotechnology deals with living organisms and biological processes; astrophysics is unrelated.
Correct answer is: Astrophysical calculations