Here below some basic MCQ’s of biotechnology and its application with answer which is explained in details.
- Which of the following is used as a vector in gene therapy?
a) Plasmid
b) Liposome
c) Virus
d) All of the above
Answer: d) All of the above
Explanation: Gene therapy involves inserting functional genes into cells to replace or repair defective ones. Various vectors are used to carry the desired gene into target cells: Plasmids are small DNA molecules that can replicate independently.
Liposomes are lipid-based carriers that fuse with cell membranes to deliver genes.
Viruses, such as retroviruses or adenoviruses, are commonly used as vectors due to their ability to infect cells efficiently.
All of these options can be employed depending on the specific requirements of the therapy.
- Golden rice is genetically modified to contain high levels of:
a) Vitamin A
b) Iron
c) Vitamin C
d) Protein
Answer: a) Vitamin A
Explanation: Golden rice is engineered to produce β-carotene, a precursor of Vitamin A, in the rice grains. This biofortification helps to address Vitamin A deficiency in populations dependent on rice as a staple food, particularly in developing countries.
- Which of the following is a bio-pesticide?
a) Bt toxin
b) DDT
c) Malathion
d) Endosulfan
Answer: a) Bt toxin
Explanation: Bt toxin is produced by the bacterium Bacillus thuringiensis. This toxin is specific to insect pests and is widely used as a biological pesticide in agriculture, especially in genetically modified (GM) crops like Bt cotton. Chemical pesticides like DDT, Malathion, and Endosulfan are synthetic and can harm the environment and non-target organisms, unlike Bt toxin, which is considered eco-friendly.
- The first transgenic cow, Rosie, produced milk rich in which protein?
a) Casein
b) Alpha-lactalbumin
c) Beta-lactoglobulin
d) Alpha-1-antitrypsin
Answer: d) Alpha-1-antitrypsin
Explanation: Rosie was a transgenic cow that produced human alpha-1-antitrypsin in her milk. This protein is used in the treatment of emphysema. The milk from Rosie was termed “humanized” because of its medicinal value and potential to benefit individuals with specific genetic disorders.
- Cry genes used in Bt crops are obtained from which organism?
a) Escherichia coli
b) Bacillus subtilis
c) Bacillus thuringiensis
d) Pseudomonas fluorescens
Answer: c) Bacillus thuringiensis
Explanation: The Cry genes from Bacillus thuringiensis (Bt) encode for insecticidal proteins, which are toxic to insect larvae but harmless to humans and other animals. These genes are inserted into crops like cotton and maize, making them resistant to insect pests such as the cotton bollworm.
- Which of the following enzymes is commonly used in PCR (Polymerase Chain Reaction)?
a) Ligase
b) Taq polymerase
c) DNAase
d) Helicase
Answer: b) Taq polymerase
Explanation: Taq polymerase is a heat-stable enzyme obtained from the bacterium Thermus aquaticus. It is used in PCR because it can withstand the high temperatures required for DNA denaturation and can efficiently catalyze the synthesis of DNA strands during the amplification process.
- In RNA interference (RNAi), the target mRNA is silenced by:
a) siRNA
b) tRNA
c) rRNA
d) mRNA
Answer: a) siRNA
Explanation: RNA interference (RNAi) is a biological process where small interfering RNA (siRNA) molecules bind to complementary sequences in target mRNA, leading to its degradation or preventing its translation. This process regulates gene expression and has applications in gene silencing and therapeutic interventions.
- The production of insulin using recombinant DNA technology was first achieved in which organism?
a) Saccharomyces cerevisiae
b) Escherichia coli
c) Bacillus thuringiensis
d) Pseudomonas putida
Answer: b) Escherichia coli
Explanation: The production of human insulin using recombinant DNA technology was first achieved in Escherichia coli (E. coli) bacteria. The human insulin gene was inserted into bacterial plasmids, and the bacteria were then cultured to produce insulin, which could be harvested and purified for medical use.
- Which of the following is not a part of downstream processing in biotechnology?
a) Separation
b) Purification
c) Fermentation
d) Packaging
Answer: c) Fermentation
Explanation: Downstream processing refers to the steps involved after the production phase to recover and purify the biotechnological product. These include separation, purification, and packaging. Fermentation is part of upstream processing, where the product is produced, usually through microbial or cell culture systems.
- Gene silencing in plants to combat viral infections is achieved through:
a) Hybridization
b) Genetic mutations
c) RNA interference
d) Antibiotics
Answer: c) RNA interference
Explanation: Gene silencing using RNA interference (RNAi) in plants can protect against viral infections. This method involves introducing small RNA molecules that are complementary to viral RNA, thereby degrading the viral RNA or blocking its translation, which prevents the virus from replicating.
- Which of the following is NOT a feature of genetically modified (GM) crops?
a) Resistance to pests
b) Increased shelf life
c) Production of bioethanol
d) Enhanced nutritional value
Answer: c) Production of bioethanol
Explanation: GM crops are engineered for various traits, such as pest resistance, enhanced nutritional value (like Golden Rice with Vitamin A), and increased shelf life. However, bioethanol production involves using crops for biofuel purposes and is not a direct feature of genetic modification in crops.
- Bt cotton is resistant to which pest?
a) Aphids
b) Whiteflies
c) Cotton bollworm
d) Spider mites
Answer: c) Cotton bollworm
Explanation: Bt cotton is genetically modified to produce the Cry proteins from Bacillus thuringiensis, which are toxic to the larvae of the cotton bollworm, reducing crop loss due to pest attacks.
- Which of the following is NOT used in genetic engineering?
a) Restriction enzymes
b) DNA ligase
c) DNA polymerase
d) Amylase
Answer: d) Amylase
Explanation: Genetic engineering involves manipulating DNA using restriction enzymes (to cut DNA), DNA ligase (to join DNA fragments), and DNA polymerase (for replication). Amylase, an enzyme that breaks down starch into sugars, is not involved in genetic engineering.
- Which technique is used for DNA fingerprinting?
a) PCR
b) RFLP
c) ELISA
d) Gel electrophoresis
Answer: b) RFLP
Explanation: Restriction Fragment Length Polymorphism (RFLP) is used in DNA fingerprinting to detect variations in DNA sequences by cutting DNA with restriction enzymes and separating fragments using gel electrophoresis. This helps in identifying individuals based on their unique DNA patterns.
- Which of the following is a disadvantage of genetically modified crops?
a) Reduced pesticide use
b) Increased crop yield
c) Development of resistance in pests
d) Enhanced nutritional content
Answer: c) Development of resistance in pests
Explanation: One potential disadvantage of GM crops, like Bt cotton, is that over time, pests may evolve resistance to the toxins produced by the crops. This can reduce the effectiveness of the genetic modification and require the use of additional pest control measures.
- Which of the following organisms is used to produce insulin in genetic engineering?
a) Saccharomyces cerevisiae
b) Escherichia coli
c) Aspergillus niger
d) Pseudomonas putida
Answer: b) Escherichia coli
Explanation: Insulin is produced using recombinant DNA technology by inserting the human insulin gene into Escherichia coli. This bacterium then produces insulin, which is harvested for medical use, especially for patients with diabetes.
- Agrobacterium tumefaciens is widely used in biotechnology for:
a) Bioremediation
b) Gene cloning in plants
c) Protein synthesis
d) Nitrogen fixation
Answer: b) Gene cloning in plants
Explanation: Agrobacterium tumefaciens is a bacterium that naturally transfers part of its DNA (T-DNA) into plant cells, causing crown gall disease. In biotechnology, it is harnessed as a vector to insert desired genes into plant genomes for the development of genetically modified plants.
- Which of the following is not a method of introducing recombinant DNA into host cells?
a) Microinjection
b) Electroporation
c) Heat shock
d) Centrifugation
Answer: d) Centrifugation
Explanation: Methods like microinjection, electroporation, and heat shock are commonly used to introduce recombinant DNA into host cells. Centrifugation, on the other hand, is used to separate mixtures based on density and is not a method for DNA transformation.
- What is the role of Ti plasmid in biotechnology?
a) It is used to induce mutations.
b) It serves as a vector for gene transfer in plants.
c) It enhances protein production in microbes.
d) It protects plants from viruses.
Answer: b) It serves as a vector for gene transfer in plants.
Explanation: The Ti plasmid (Tumor-inducing plasmid) from Agrobacterium tumefaciens is used in plant biotechnology as a vector to deliver genes into plant cells. It integrates part of its DNA into the plant genome, making it a useful tool for producing genetically modified plants.
- The process by which identical copies of an organism are produced through non-sexual means is called:
a) Hybridization
b) Cloning
c) Grafting
d) Pollination
Answer: b) Cloning
Explanation: Cloning is the process of creating identical genetic copies of an organism through asexual reproduction, bypassing the need for fertilization. This can be done via techniques like somatic cell nuclear transfer (SCNT) in animals or tissue culture in plants.
- Which of the following is an example of a genetically engineered product?
a) Natural penicillin
b) Bt corn
c) Yeast extract
d) Vinegar
Answer: b) Bt corn
Explanation: Bt corn is a genetically modified crop that expresses Cry proteins from Bacillus thuringiensis, making it resistant to specific insect pests like the European corn borer.
- Which enzyme is used to cut DNA at specific sites?
a) Ligase
b) Polymerase
c) Restriction enzyme
d) Helicase
Answer: c) Restriction enzyme
Explanation: Restriction enzymes, also known as molecular scissors, cut DNA at specific recognition sequences. These enzymes are essential tools in genetic engineering for manipulating DNA.
- Somatic gene therapy refers to the modification of:
a) Reproductive cells
b) Somatic cells
c) Germline cells
d) Embryos
Answer: b) Somatic cells
Explanation: Somatic gene therapy involves altering the genes in the somatic (non-reproductive) cells of an individual. This therapy is used to treat genetic disorders without passing the modifications to offspring, unlike germline gene therapy.
- A biological control agent for mosquito larvae is:
a) Bacillus thuringiensis israelensis
b) Escherichia coli
c) Penicillium notatum
d) Rhizobium
Answer: a) Bacillus thuringiensis israelensis
Explanation: Bacillus thuringiensis israelensis produces toxins that are specifically lethal to mosquito larvae. This bio-control agent is used in water bodies to control mosquito populations, thus helping in the prevention of diseases like malaria and dengue.
- The main principle behind the use of PCR (Polymerase Chain Reaction) is:
a) DNA denaturation
b) DNA amplification
c) Protein synthesis
d) RNA transcription
Answer: b) DNA amplification
Explanation: PCR is a molecular biology technique used to amplify specific DNA sequences, generating millions of copies of the target DNA. This process is fundamental in diagnostics, cloning, and genetic analysis.
- Which of the following is NOT a component of PCR?
a) Primers
b) dNTPs
c) RNA polymerase
d) Taq polymerase
Answer: c) RNA polymerase
Explanation: PCR uses DNA primers, dNTPs (deoxynucleoside triphosphates), and Taq polymerase (a heat-resistant DNA polymerase). RNA polymerase is used in transcription (synthesis of RNA from DNA) and is not a component of PCR.
- Transgenic animals are primarily used for:
a) Vaccine development
b) Gene therapy
c) Studying diseases and drug testing
d) Nitrogen fixation
Answer: c) Studying diseases and drug testing
Explanation: Transgenic animals, which have foreign genes introduced into their genomes, are used to study the progression of diseases and to test new drugs. This helps researchers understand the role of specific genes in disease mechanisms and treatment.
- Which of the following diseases can be treated using gene therapy?
a) Malaria
b) Cystic fibrosis
c) Typhoid
d) Influenza
Answer: b) Cystic fibrosis
Explanation: Gene therapy holds promise for treating genetic disorders like cystic fibrosis by introducing functional copies of the defective gene into the patient’s cells. Other diseases, like malaria, typhoid, and influenza, are caused by pathogens and are treated with drugs or vaccines.
- Which organism is most commonly used in the production of bioethanol?
a) Saccharomyces cerevisiae
b) Escherichia coli
c) Rhizobium
d) Penicillium chrysogenum
Answer: a) Saccharomyces cerevisiae
Explanation: Saccharomyces cerevisiae, commonly known as baker’s yeast, is used in bioethanol production. It ferments sugars into ethanol, making it a key organism in the biofuel industry.
- Gene therapy involves:
a) Inserting foreign DNA into germ cells
b) Replacing defective genes with functional ones
c) Preventing mutations in genes
d) Enhancing protein synthesis in the body
Answer: b) Replacing defective genes with functional ones
Explanation: Gene therapy is a technique that involves correcting defective genes responsible for disease development by introducing functional genes into the patient’s cells. This approach has potential for treating genetic disorders, such as cystic fibrosis and hemophilia.
- Which of the following is an example of ex vivo gene therapy?
a) Injection of a virus carrying a normal gene directly into a patient
b) Introduction of engineered cells into the patient’s body after manipulation outside the body
c) Injection of siRNA to silence a gene
d) Use of CRISPR-Cas9 to edit the gene directly inside the patient
Answer: b) Introduction of engineered cells into the patient’s body after manipulation outside the body
Explanation:
Ex vivo gene therapy involves removing cells from a patient, modifying them genetically outside the body, and then reintroducing them into the patient. In contrast, in vivo gene therapy involves delivering the genetic material directly into the patient.
- Which technology was first used for the commercial production of human insulin?
a) CRISPR-Cas9
b) Recombinant DNA technology
c) Somatic gene therapy
d) DNA fingerprinting
Answer: b) Recombinant DNA technology
Explanation:
Recombinant DNA technology was first used to produce human insulin by inserting the insulin gene into bacteria such as Escherichia coli. These genetically modified bacteria produced insulin, which was harvested and purified for medical use.
- Bt toxin is toxic to insects because it:
a) Destroys the insect’s nervous system
b) Inhibits the insect’s protein synthesis
c) Binds to specific receptors in the insect’s gut, causing cell lysis
d) Prevents insect reproduction
Answer: c) Binds to specific receptors in the insect’s gut, causing cell lysis
Explanation:
Bt toxin, produced by Bacillus thuringiensis, binds to receptors in the gut of specific insect larvae. This causes the cells in the gut to lyse, leading to the death of the insect.
- What is the function of DNA ligase in recombinant DNA technology?
a) It cuts DNA at specific sequences.
b) It amplifies DNA fragments.
c) It joins DNA fragments together.
d) It separates DNA fragments by size.
Answer: c) It joins DNA fragments together.
Explanation:
DNA ligase is an enzyme that facilitates the joining of DNA fragments by forming phosphodiester bonds between the ends of the DNA strands. This is essential in creating recombinant DNA molecules.
- Which of the following is used as a marker gene to identify transformed cells in genetic engineering?
a) Insulin gene
b) GFP (Green Fluorescent Protein)
c) Cry gene
d) Myosin gene
Answer: b) GFP (Green Fluorescent Protein)
Explanation:
GFP is commonly used as a marker gene in genetic engineering. Cells expressing GFP can be easily identified due to their fluorescence under UV light, helping to confirm successful transformation.
- Flavr Savr, the first genetically modified tomato, was engineered for:
a) Insect resistance
b) Herbicide tolerance
c) Delayed ripening
d) Improved flavor
Answer: c) Delayed ripening
Explanation:
The Flavr Savr tomato was genetically modified to delay the ripening process, which extended its shelf life. This was achieved by reducing the activity of the enzyme polygalacturonase, which breaks down pectin in the tomato cell walls.
- What is the role of CRISPR-Cas9 in biotechnology?
a) To induce mutations in specific genes
b) To perform genome editing by cutting DNA at specific sites
c) To amplify DNA for sequencing
d) To inhibit RNA synthesis
Answer: b) To perform genome editing by cutting DNA at specific sites
Explanation:
CRISPR-Cas9 is a revolutionary genome-editing tool that allows precise cutting and modification of DNA at specific locations. It has vast applications in genetic research, gene therapy, and biotechnology.
- Which of the following is a common application of RNA interference (RNAi)?
a) Increasing crop yield
b) Silencing specific genes to study their function
c) Promoting genetic diversity in crops
d) Cloning entire organisms
Answer: b) Silencing specific genes to study their function
Explanation:
RNA interference (RNAi) is used to silence or knock down the expression of specific genes, allowing researchers to study gene function and investigate the effects of reducing the levels of specific proteins.
- Which of the following is NOT a step in recombinant DNA technology?
a) Isolation of the desired gene
b) Use of DNA polymerase to cut the DNA
c) Ligation of the DNA into a vector
d) Introduction of the recombinant vector into the host cell
Answer: b) Use of DNA polymerase to cut the DNA
Explanation:
DNA polymerase is not used to cut DNA; instead, restriction enzymes are responsible for cutting DNA at specific sequences. DNA polymerase is used to replicate DNA during the amplification process in PCR.
- Which bacterium is commonly used in the production of transgenic plants?
a) Escherichia coli
b) Agrobacterium tumefaciens
c) Pseudomonas aeruginosa
d) Rhizobium
Answer: b) Agrobacterium tumefaciens
Explanation:
Agrobacterium tumefaciens is widely used in genetic engineering to create transgenic plants. Its Ti plasmid can be modified to deliver desired genes into the plant genome.
- Which of the following is a genetically modified organism (GMO) used to produce vaccines?
a) Penicillium chrysogenum
b) Saccharomyces cerevisiae
c) Escherichia coli
d) Mycobacterium tuberculosis
Answer: b) Saccharomyces cerevisiae
Explanation:
The yeast Saccharomyces cerevisiae has been genetically modified to produce recombinant proteins for vaccines, such as the hepatitis B vaccine, by expressing the virus surface antigen.
- Transgenic animals have been used for all of the following EXCEPT:
a) Producing therapeutic proteins
b) Studying gene function
c) Nitrogen fixation in soil
d) Drug testing
Answer: c) Nitrogen fixation in soil
Explanation:
Transgenic animals are not involved in nitrogen fixation, which is a process performed by certain bacteria and plants. Instead, transgenic animals are used for research, drug testing, and producing proteins for therapeutic use.
- Gene therapy is most effective in treating:
a) Genetic disorders
b) Viral infections
c) Parasitic diseases
d) Autoimmune diseases
Answer: a) Genetic disorders
Explanation:
Gene therapy is particularly effective in treating genetic disorders by correcting or replacing defective genes in affected individuals. It is less applicable to viral, parasitic, or autoimmune diseases.
- Which of the following vectors is used to transfer genes into animal cells?
a) Ti plasmid
b) Retrovirus
c) T4 bacteriophage
d) Cosmid
Answer: b) Retrovirus
Explanation:
Retroviruses are commonly used vectors to transfer genes into animal cells, as they can integrate their genetic material into the host cell genome. This makes them effective in gene therapy and genetic research.
- Which enzyme is responsible for the polymerization of nucleotides during DNA replication?
a) DNA polymerase
b) RNA polymerase
c) Helicase
d) Ligase
Answer: a) DNA polymerase
Explanation:
DNA polymerase is the enzyme that catalyzes the addition of nucleotides to a growing DNA strand during DNA replication. It ensures the correct pairing of nucleotides based on the template strand.
- Which of the following is used to separate DNA fragments based on their size?
a) PCR
b) Gel electrophoresis
c) DNA sequencing
d) Restriction digestion
Answer: b) Gel electrophoresis
Explanation:
Gel electrophoresis is a technique used to separate DNA fragments by size. DNA fragments are placed in a gel, and an electric current is applied, causing smaller fragments to move faster through the gel matrix than larger ones.
- Which of the following is used to create genetically modified organisms (GMOs)?
a) Bioremediation
b) Recombinant DNA technology
c) Phylogenetics
d) DNA fingerprinting
Answer: b) Recombinant DNA technology
Explanation:
GMOs are created using recombinant DNA technology, which involves inserting a desired gene from one organism into the genome of another, leading to the expression of new traits in the recipient organism.
- The process of creating identical genetic copies of an organism through artificial means is called:
a) Gene therapy
b) Cloning
c) Genetic drift
d) Hybridization
Answer: b) Cloning
Explanation:
Cloning refers to the process of creating identical copies of an organism through non-sexual means, often using somatic cell nuclear transfer or other techniques to replicate the genome.
- Which of the following methods is used to introduce DNA into plant cells?
a) Gene gun
b) Microinjection
c) Transformation
d) Electroporation
Answer: a) Gene gun
Explanation:
The gene gun (or biolistic particle delivery system) is used to deliver DNA into plant cells by shooting microscopic particles coated with DNA into the plant tissue. This method is commonly used to create genetically modified plants.
- Which of the following is a benefit of Bt crops?
a) Increased use of chemical pesticides
b) Enhanced resistance to viruses
c) Reduced need for pesticide application
d) Faster ripening
Answer: c) Reduced need for pesticide application
Explanation:
Bt crops produce Cry proteins that are toxic to certain pests, reducing the need for chemical pesticide applications and leading to more sustainable agricultural practices.
- Which of the following enzymes is used in the PCR (Polymerase Chain Reaction) technique?
a) RNA polymerase
b) DNA ligase
c) Taq polymerase
d) Reverse transcriptase
Answer: c) Taq polymerase
Explanation:
Taq polymerase, derived from the bacterium Thermus aquaticus, is a heat-stable DNA polymerase used in PCR to amplify DNA sequences through repeated cycles of heating and cooling.
- Which of the following is a disadvantage of using genetically modified organisms (GMOs) in agriculture?
a) Increased crop yield
b) Resistance to pests
c) Potential cross-breeding with wild species
d) Reduced pesticide use
Answer: c) Potential cross-breeding with wild species
Explanation:
One concern with GMOs is the possibility of gene flow, where the genetically modified genes might spread to wild relatives, potentially causing ecological imbalances or the development of “superweeds.”
- Golden rice has been genetically engineered to combat:
a) Vitamin A deficiency
b) Vitamin D deficiency
c) Iron deficiency anemia
d) Calcium deficiency
Answer: a) Vitamin A deficiency
Explanation:
Golden Rice is a genetically modified variety of rice that has been engineered to produce beta-carotene, a precursor of Vitamin A, aimed at reducing Vitamin A deficiency, particularly in developing countries.
- Which technique is used to amplify small quantities of DNA for further analysis?
a) Southern blotting
b) Polymerase Chain Reaction (PCR)
c) Northern blotting
d) DNA sequencing
Answer: b) Polymerase Chain Reaction (PCR)
Explanation:
PCR is a molecular biology technique used to amplify small quantities of DNA, making it possible to generate millions of copies of a specific DNA sequence for further analysis.
- Which of the following techniques is used to introduce foreign DNA into bacterial cells?
a) Gel electrophoresis
b) Microinjection
c) Transformation
d) Blotting
Answer: c) Transformation
Explanation:
Transformation is the process by which foreign DNA is introduced into bacterial cells, usually by making the bacterial cells competent to take up DNA, often using heat shock or electroporation.
- Which of the following is an example of a transgenic organism?
a) A sheep that produces human insulin
b) A bacterium that decomposes oil spills
c) A plant with increased drought tolerance
d) A bacterium that fixes nitrogen
Answer: a) A sheep that produces human insulin
Explanation:
A transgenic organism is one that has been genetically modified to carry genes from another species. In this case, a sheep that produces human insulin is an example of a transgenic organism.
- Which of the following is used as a selectable marker in the process of genetic engineering?
a) Antibiotic resistance gene
b) Hemoglobin gene
c) Chlorophyll gene
d) Insulin gene
Answer: a) Antibiotic resistance gene
Explanation:
Selectable markers, like antibiotic resistance genes, are used to identify cells that have successfully incorporated the foreign gene during genetic engineering. Cells that contain the marker gene survive when grown in the presence of the corresponding antibiotic.
- Which of the following methods is used to detect specific sequences of DNA?
a) Western blotting
b) Northern blotting
c) Southern blotting
d) Eastern blotting
Answer: c) Southern blotting
Explanation:
Southern blotting is a technique used to detect specific DNA sequences within a DNA sample by transferring the DNA onto a membrane and probing it with a labeled DNA probe that hybridizes with the target sequence.
- Gene therapy is most suitable for treating diseases caused by:
a) Viruses
b) Bacteria
c) Mutations in single genes
d) Nutritional deficiencies
Answer: c) Mutations in single genes
Explanation:
Gene therapy is primarily used to treat genetic disorders caused by mutations in single genes, such as cystic fibrosis or sickle cell anemia, by delivering functional copies of the defective gene to the patient’s cells.
- Which of the following is a key component of the CRISPR-Cas9 system?
a) Reverse transcriptase
b) Guide RNA
c) Taq polymerase
d) DNA ligase
Answer: b) Guide RNA
Explanation:
In the CRISPR-Cas9 system, guide RNA (gRNA) directs the Cas9 enzyme to the specific DNA sequence that is to be cut, allowing for precise genome editing.
- Which of the following enzymes is used to reverse transcribe RNA into DNA?
a) DNA polymerase
b) Ligase
c) Reverse transcriptase
d) Restriction enzyme
Answer: c) Reverse transcriptase
Explanation:
Reverse transcriptase is an enzyme used to synthesize complementary DNA (cDNA) from an RNA template. This is especially useful in studying gene expression by converting mRNA into DNA for cloning or PCR.
- The enzyme responsible for cutting DNA at specific nucleotide sequences is:
a) DNA ligase
b) Helicase
c) Restriction endonuclease
d) RNA polymerase
Answer: c) Restriction endonuclease
Explanation:
Restriction endonucleases (restriction enzymes) cut DNA at specific recognition sequences, which is essential for manipulating and recombining DNA in genetic engineering.
- Which organism has been genetically modified to produce human growth hormone?
a) Escherichia coli
b) Saccharomyces cerevisiae
c) Rhizobium
d) Penicillium notatum
Answer: a) Escherichia coli
Explanation:
Escherichia coli has been genetically modified to produce human growth hormone (hGH) using recombinant DNA technology. The hGH gene is inserted into E. coli, which then expresses the hormone for therapeutic use.
- Which of the following crops has been genetically modified for herbicide resistance?
a) Bt cotton
b) Flavr Savr tomato
c) Roundup Ready soybean
d) Golden Rice
Answer: c) Roundup Ready soybean
Explanation:
Roundup Ready soybeans are genetically engineered to be resistant to the herbicide glyphosate, allowing farmers to apply the herbicide to kill weeds without harming the crop.
- The production of genetically identical organisms through asexual reproduction is known as:
a) Hybridization
b) Cross-breeding
c) Cloning
d) Transgenesis
Answer: c) Cloning
Explanation:
Cloning is the process of creating genetically identical copies of an organism through asexual reproduction, often using techniques like somatic cell nuclear transfer.
- Which of the following techniques can be used to analyze gene expression by measuring mRNA levels?
a) Southern blotting
b) Northern blotting
c) Western blotting
d) PCR
Answer: b) Northern blotting
Explanation:
Northern blotting is used to detect and measure mRNA levels, providing insights into gene expression patterns. It involves separating RNA by electrophoresis and probing with a complementary RNA or DNA sequence.
- In genetic engineering, what is the purpose of a vector?
a) To break down proteins
b) To amplify DNA
c) To carry foreign genes into a host cell
d) To degrade RNA
Answer: c) To carry foreign genes into a host cell
Explanation:
A vector, such as a plasmid or virus, is used in genetic engineering to deliver foreign DNA into a host cell where it can be expressed or replicated.
- Which of the following is commonly used as a vector in animal gene therapy?
a) Ti plasmid
b) Bacteriophage
c) Retrovirus
d) RNA polymerase
Answer: c) Retrovirus
Explanation:
Retroviruses are commonly used as vectors in animal gene therapy because they can integrate their genetic material into the host cell’s genome, making them useful for stable, long-term expression of therapeutic genes.
- RNA interference (RNAi) technology can be used to:
a) Increase the expression of a gene
b) Silence or reduce the expression of a gene
c) Amplify DNA
d) Mutate a gene
Answer: b) Silence or reduce the expression of a gene
Explanation:
RNA interference (RNAi) is a method used to silence or reduce the expression of specific genes by degrading the mRNA, thus preventing the production of the corresponding protein.
- Which of the following is NOT true about genetically modified organisms (GMOs)?
a) They can be used to improve crop yields.
b) They are always beneficial to the environment.
c) They can be engineered for pest resistance.
d) They can reduce the need for chemical pesticides.
Answer: b) They are always beneficial to the environment.
Explanation:
While GMOs can have benefits like improving crop yields and reducing pesticide use, they are not always beneficial to the environment. There are concerns about unintended ecological effects, such as gene flow to wild species.
- Which bacterium is commonly used in the production of recombinant insulin?
a) Bacillus subtilis
b) Escherichia coli
c) Rhizobium
d) Pseudomonas
Answer: b) Escherichia coli
Explanation:
Escherichia coli is used in the production of recombinant insulin by inserting the human insulin gene into the bacterial genome, allowing the bacteria to produce insulin for medical use.
- Which of the following is used to study protein-protein interactions?
a) Southern blotting
b) Yeast two-hybrid system
c) Northern blotting
d) PCR
Answer: b) Yeast two-hybrid system
Explanation:
The yeast two-hybrid system is a genetic technique used to study protein-protein interactions by determining if two proteins physically interact with each other in a yeast cell.
- Which of the following is NOT a method of gene transfer in plants?
a) Agrobacterium-mediated transformation
b) Biolistics (gene gun)
c) Microinjection
d) Southern blotting
Answer: d) Southern blotting
Explanation:
Southern blotting is a technique used to detect specific DNA sequences and is not a method of gene transfer. Gene transfer in plants is typically accomplished through methods like Agrobacterium-mediated transformation or biolistics.
- In which of the following biotechnological processes are Bacillus thuringiensis (Bt) toxins used?
a) Gene therapy
b) Bioremediation
c) Insect-resistant crops
d) Production of antibiotics
Answer: c) Insect-resistant crops
Explanation:
Bt toxins produced by Bacillus thuringiensis are used in genetically engineered crops to confer resistance against certain insect pests. Bt crops, such as Bt cotton, express these toxins, which kill the larvae of specific insects.
- The purpose of using restriction enzymes in recombinant DNA technology is to:
a) Amplify DNA
b) Cut DNA at specific sites
c) Ligate DNA fragments
d) Degrade RNA
Answer: b) Cut DNA at specific sites
Explanation:
Restriction enzymes, also known as molecular scissors, are used to cut DNA at specific recognition sequences, facilitating the insertion of foreign genes into vectors during recombinant DNA technology.
- Which of the following is an advantage of genetically modified (GM) crops?
a) Increased biodiversity
b) Resistance to pests
c) Elimination of all chemical fertilizers
d) Faster natural evolution
Answer: b) Resistance to pests
Explanation:
GM crops can be engineered for pest resistance, reducing the need for chemical pesticides. This helps protect the crops from insect damage and can lead to higher yields and reduced environmental impact from pesticide use.
- Which of the following is used as a molecular marker in genetic studies?
a) Insulin gene
b) Hemoglobin gene
c) GFP (Green Fluorescent Protein)
d) Cytochrome C
Answer: c) GFP (Green Fluorescent Protein)
Explanation:
GFP is used as a molecular marker in genetic studies. It fluoresces under UV light, making it easy to track the expression of genes or the presence of specific cells that have taken up foreign DNA.
- Which process is used to increase the number of copies of a particular DNA sequence?
a) Polymerase Chain Reaction (PCR)
b) DNA sequencing
c) RNA interference (RNAi)
d) Gene cloning
Answer: a) Polymerase Chain Reaction (PCR)
Explanation:
PCR is a technique used to amplify or increase the number of copies of a specific DNA sequence. This method is crucial for genetic research, diagnostics, and forensic applications.
- Which organism is used to produce bioethanol from biomass?
a) Saccharomyces cerevisiae
b) Escherichia coli
c) Penicillium
d) Pseudomonas
Answer: a) Saccharomyces cerevisiae
Explanation:
Saccharomyces cerevisiae, also known as baker’s yeast, is commonly used in the fermentation process to produce bioethanol from biomass by converting sugars into ethanol.
- Which of the following is an application of bioinformatics in biotechnology?
a) DNA sequencing
b) Cloning of genes
c) Protein purification
d) Gene transfer
Answer: a) DNA sequencing
Explanation:
Bioinformatics plays a significant role in analyzing and interpreting DNA sequences, which is crucial for understanding genetic information, identifying genes, and studying evolutionary relationships.
- What is the role of a vector in genetic engineering?
a) To replicate proteins
b) To carry the gene of interest into the host cell
c) To induce mutations in DNA
d) To degrade RNA
Answer: b) To carry the gene of interest into the host cell
Explanation:
Vectors are DNA molecules, such as plasmids or viruses, that are used to carry the gene of interest into a host cell, where it can be expressed or replicated as part of the genetic engineering process.
- Which of the following is a feature of gene therapy?
a) Replacing defective genes in somatic cells
b) Introducing genes into germ cells
c) Silencing the expression of viral genes
d) Inserting foreign DNA into the mitochondrial genome
Answer: a) Replacing defective genes in somatic cells
Explanation:
Gene therapy typically involves replacing defective genes in somatic cells to correct genetic disorders. This technique has been used to treat conditions like cystic fibrosis and muscular dystrophy.
- Which of the following is used to determine the exact sequence of nucleotides in a DNA molecule?
a) PCR
b) DNA sequencing
c) Northern blotting
d) Transformation
Answer: b) DNA sequencing
Explanation:
DNA sequencing is the process used to determine the precise order of nucleotides within a DNA molecule. This technique is critical for genomics, evolutionary biology, and medical research.
- Which of the following is commonly used to introduce foreign DNA into plant cells?
a) Retrovirus
b) Gene gun
c) T4 bacteriophage
d) Agrobacterium tumefaciens
Answer: d) Agrobacterium tumefaciens
Explanation:
Agrobacterium tumefaciens is commonly used to introduce foreign DNA into plant cells due to its ability to transfer its Ti plasmid, which integrates foreign genes into the plant genome.
- The Human Genome Project aimed to:
a) Map all the genes in the human genome
b) Clone the human genome
c) Create genetically modified humans
d) Eliminate all genetic diseases
Answer: a) Map all the genes in the human genome
Explanation:
The Human Genome Project was an international research effort aimed at sequencing and mapping all the genes in the human genome, providing a comprehensive understanding of human genetics.
- Which of the following is a technique for detecting specific proteins?
a) Southern blotting
b) Northern blotting
c) Western blotting
d) PCR
Answer: c) Western blotting
Explanation:
Western blotting is a technique used to detect specific proteins in a sample by separating them using gel electrophoresis and then transferring them to a membrane where they are probed with antibodies.
- Which of the following is a benefit of genetically modified (GM) crops?
a) Increased use of pesticides
b) Reduced crop yields
c) Resistance to herbicides
d) Increased susceptibility to diseases
Answer: c) Resistance to herbicides
Explanation:
GM crops can be engineered to be resistant to specific herbicides, allowing farmers to use these herbicides to control weeds without harming the crop.
- Which of the following processes is used to introduce DNA into animal cells?
a) Microinjection
b) Electrophoresis
c) Southern blotting
d) PCR
Answer: a) Microinjection
Explanation:
Microinjection involves directly injecting foreign DNA into the nucleus of an animal cell using a fine needle. This technique is commonly used in creating transgenic animals.
- What is the function of reverse transcriptase in genetic engineering?
a) To cut DNA at specific sites
b) To transcribe DNA into RNA
c) To reverse transcribe RNA into DNA
d) To ligate DNA fragments
Answer: c) To reverse transcribe RNA into DNA
Explanation:
Reverse transcriptase is an enzyme that synthesizes complementary DNA (cDNA) from an RNA template, which is useful in studying gene expression and creating cDNA libraries.
- Which of the following is an ethical concern related to genetic engineering?
a) Increased agricultural productivity
b) Creation of “designer” babies
c) Development of new medicines
d) Gene therapy for genetic disorders
Answer: b) Creation of “designer” babies
Explanation:
Ethical concerns in genetic engineering include the possibility of using the technology to create “designer” babies, where genes are modified for non-medical reasons such as physical traits or intelligence.
- The CRISPR-Cas9 system is primarily used for:
a) Gene cloning
b) Genome editing
c) DNA replication
d) RNA interference
Answer: b) Genome editing
Explanation:
CRISPR-Cas9 is a powerful tool used for precise genome editing, allowing scientists to cut and modify DNA at specific locations within an organism’s genome.
- Which of the following is used to separate DNA fragments by size?
a) PCR
b) Gel electrophoresis
c) Southern blotting
d) Transformation
Answer: b) Gel electrophoresis
Explanation:
Gel electrophoresis is a technique used to separate DNA fragments based on their size by applying an electric current to a gel matrix. Smaller fragments move faster through the gel than larger ones.
- Which of the following enzymes is used to join DNA fragments together?
a) DNA polymerase
b) RNA polymerase
c) DNA ligase
d) Reverse transcriptase
Answer: c) DNA ligase
Explanation:
DNA ligase is an enzyme that joins DNA fragments together by forming phosphodiester bonds between adjacent nucleotides. It is commonly used in molecular cloning to join foreign DNA into vectors.
- In which of the following processes is RNAi technology used?
a) Increasing gene expression
b) Silencing gene expression
c) DNA replication
d) Protein translation
Answer: b) Silencing gene expression
Explanation:
RNA interference (RNAi) technology is used to silence or reduce the expression of specific genes by degrading the corresponding mRNA, preventing the production of the target protein.
- Which of the following is a genetically modified crop developed to resist pests?
a) Flavr Savr tomato
b) Bt cotton
c) Golden Rice
d) Roundup Ready soybean
Answer: b) Bt cotton
Explanation:
Bt cotton is a genetically modified crop that produces insecticidal proteins from Bacillus thuringiensis, making it resistant to certain pests such as bollworms.
- Which of the following is NOT a benefit of genetically modified (GM) crops?
a) Increased crop yield
b) Reduced use of pesticides
c) Improved resistance to pests
d) Elimination of all health risks
Answer: d) Elimination of all health risks
Explanation:
While GM crops can offer benefits like increased yield, pest resistance, and reduced pesticide use, they do not eliminate all health risks, and there are still ongoing debates about their long-term safety.
- The enzyme used to cut DNA at specific sites is:
a) DNA ligase
b) Helicase
c) Restriction endonuclease
d) DNA polymerase
Answer: c) Restriction endonuclease
Explanation:
Restriction endonucleases (restriction enzymes) cut DNA at specific recognition sites, which is a key step in genetic engineering for creating recombinant DNA.
- Which of the following is a potential environmental risk of genetically modified organisms (GMOs)?
a) Improved crop yield
b) Crossbreeding with wild species
c) Reduced pesticide use
d) Increased resistance to drought
Answer: b) Crossbreeding with wild species
Explanation:
One potential environmental risk of GMOs is gene flow, where genetically modified traits may spread to wild species, potentially creating ecological imbalances or leading to the development of resistant “superweeds.”
- Which of the following organisms has been genetically modified to produce human insulin?
a) Escherichia coli
b) Saccharomyces cerevisiae
c) Rhizobium
d) Pseudomonas
Answer: a) Escherichia coli
Explanation:
Escherichia coli has been genetically engineered to produce human insulin by inserting the human insulin gene into the bacterial genome, allowing it to produce insulin for therapeutic use.
- Which of the following is used as a molecular marker in biotechnology?
a) Green Fluorescent Protein (GFP)
b) Restriction enzyme
c) DNA ligase
d) Polymerase Chain Reaction (PCR)
Answer: a) Green Fluorescent Protein (GFP)
Explanation:
GFP is commonly used as a molecular marker to visualize and track the expression of genes or the presence of specific cells in biological research, due to its fluorescent properties
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