NEET Biotechnology and Its Applications Test

• Answer: (4) All of the above
• Explanation: Plasmids, liposomes, and bacteriophages can all serve as vectors to deliver genetic material into host cells.

Answer: (4) Ribosomes

Explanation: Ribosomes are cellular structures involved in protein synthesis and are not used as vectors for genetic engineering. Plasmids, phages, and transposons are commonly used as vectors.

• Answer: (1) Escherichia coli
• Explanation: Recombinant DNA technology enables E. coli to produce human insulin by inserting the insulin gene into its genome.

• Answer: (2) Modifying cells outside the body and reintroducing them
• Explanation: In ex vivo gene therapy, cells are removed from the patient, modified in the laboratory, and then reintroduced into the body.

• Answer: (2) It is synthesized from an RNA template.
• Explanation: cDNA (complementary DNA) is synthesized from an RNA template using reverse transcriptase and lacks introns.

• Answer: (1) They have foreign DNA integrated into their genome.
• Explanation: Transgenic organisms are those that contain DNA from a different species, integrated into their genome. This is a key feature in genetically modified organisms (GMOs).

• Answer: (4) All of the above
• Explanation: Plasmids are circular DNA molecules used in cloning because they replicate independently, have selectable markers, and contain restriction sites for gene insertion.

• Answer: (1) FISH
• Explanation: FISH uses fluorescent probes to locate specific DNA sequences on chromosomes.

• Answer: (4) The toxin causes cell wall damage to Bacillus thuringiensis.
• Explanation: Bt toxin is produced by Bacillus thuringiensis and is toxic to certain insects, not to the bacterium itself. The toxin disrupts the gut cells of insects, causing their death. It is also used in genetically modified crops to protect against pests.

• Answer: (3) Joining DNA fragments
• Explanation: DNA ligase is an enzyme used to join DNA fragments by forming phosphodiester bonds between the sugar-phosphate backbones of the DNA.

Answer: (1) To identify successful transformants

Explanation: Selectable markers, like antibiotic resistance genes, help identify cells that have successfully incorporated the desired genetic material

• Answer: (4) All of the above
• Explanation: These are types of genetic markers used to identify variations in DNA sequences for forensic and paternity analyses.

• Answer: (4) All of the above
• Explanation: Gene therapy faces challenges like immune responses, limitations in treating complex disorders, and high costs.

• Answer: (4) All of the above
• Explanation: Various methods, including electroporation, gene guns, and microinjection, are used to create genetically modified plants by introducing foreign genes into plant cells.

• Answer: (2) Thermus aquaticus
• Explanation: Taq polymerase from Thermus aquaticus is used in PCR because it is stable at high temperatures.

• Answer: (1) Enzyme-Linked Immunosorbent Assay
• Explanation: ELISA is a technique used to detect the presence of specific antigens or antibodies in a sample using enzyme-labeled immunoassay methods.

• Answer: (1) Escherichia coli
• Explanation: Human insulin is produced in Escherichia coli by inserting the human insulin gene into bacterial plasmids.

• Answer: (1) Identify transformed cells
• Explanation: Selectable markers, such as antibiotic resistance genes, help identify cells that have taken up the plasmid vector.

• Answer: (2) Herbert Boyer and Stanley Cohen
• Explanation: Boyer and Cohen pioneered recombinant DNA technology by combining DNA from different sources using restriction enzymes and ligase.

• Answer: (2) Restriction endonuclease
• Explanation: Restriction enzymes recognize specific DNA sequences and cut at these sites, facilitating DNA manipulation.

• Answer: (3) Cloning animals
• Explanation: While recombinant DNA technology has applications in insulin production, genetically modified crops, and gene therapy, animal cloning typically involves other techniques, such as somatic cell nuclear transfer.

• Answer: (4) All of the above
• Explanation: Biotechnology improves agriculture through pest-resistant crops, biofertilizers, and transgenic plants with enhanced traits.

• Answer: (1) Electroporation
• Explanation: Electroporation is a technique used to introduce recombinant DNA into cells by applying an electrical field, making the cell membrane temporarily permeable.

• Answer: (2) To initiate transcription
• Explanation: A promoter is a DNA sequence where RNA polymerase binds to start transcription, ensuring gene expression.

• Answer: (3) Restriction endonuclease
• Explanation: Restriction endonucleases are enzymes that cut DNA at specific sequences, a process that is crucial for cloning and recombinant DNA technology.

• Answer: (4) All of the above
• Explanation: Biofertilizers like Rhizobium, Azotobacter, and Mycorrhiza enhance soil fertility by fixing nitrogen or improving nutrient absorption.

• Answer: (4) Organism
• Explanation: Cloning vectors are used to carry foreign DNA into host cells for cloning. Organisms are not vectors themselves but may be hosts for cloned genes.

• Answer: (2) DNA from two different sources combined
• Explanation: Recombinant DNA involves combining DNA from two different sources to create a new genetic combination used in genetic engineering.

• Answer: (1) Agrobacterium
• Explanation: The first genetically modified plant was produced using Agrobacterium tumefaciens, which naturally transfers DNA to plant cells, making it a tool in plant genetic engineering.

Answer: (4) All of the above

Explanation: Cloning vectors like pBR322, lambda phage, and cosmids are used to transfer foreign DNA into host cells

• Answer: (1) Identical copies of a gene
• Explanation: Gene cloning generates multiple copies of the same gene, allowing for further study and application.

• Answer: (2) A mouse with a specific gene inactivated
• Explanation: Knockout mice are used in research to study the role of specific genes by inactivating them.

• Answer: (4) All of the above
• Explanation: DNA fingerprinting involves multiple techniques like PCR to amplify DNA, gel electrophoresis to separate fragments, and Southern blotting to visualize specific sequences.

• Answer: (1) A plant resistant to pests
• Explanation: Transgenic organisms are genetically modified to express foreign genes, like pest-resistant plants with inserted Bt toxin genes.

• Answer: (1) Gel electrophoresis
• Explanation: Gel electrophoresis separates DNA fragments based on size using an electric field.

• Answer: (4) Plasmids are essential for the survival of the host cell.
• Explanation: While plasmids can provide advantages like antibiotic resistance, they are not essential for the survival of the host cell, as the cell can live without them.

• Answer: (4) All of the above
• Explanation: These methods are commonly used in genetic engineering to introduce DNA into cells for transformation.

• Answer: (1) Translation in nematode.
• Explanation: RNA interference (RNAi) is a process by which RNA molecules inhibit gene expression, typically by causing the degradation of mRNA or inhibiting its translation. In nematodes, RNAi primarily affects translation, thereby preventing the synthesis of certain proteins.

• Answer: (2) Synthesize DNA from RNA
• Explanation: Reverse transcriptase is an enzyme that synthesizes complementary DNA (cDNA) from an RNA template, commonly used in the study of gene expression.

• Answer: (3) To detect specific DNA or RNA sequences
• Explanation: Probes are short, labeled sequences of DNA or RNA used to identify complementary sequences through hybridization.

• Answer: (2) Northern blotting
• Explanation: Northern blotting detects RNA sequences using labeled probes, while Southern and Western blotting are used for DNA and proteins, respectively.

• Answer: (1) It is used to create genetically modified organisms (GMOs).
• Explanation: Recombinant DNA technology is used to manipulate DNA and create GMOs by inserting genes from one organism into the DNA of another organism, making it widely applicable in agriculture, medicine, and research.

• Answer: (1) Gel electrophoresis
• Explanation: Gel electrophoresis is used to separate DNA fragments by size, where smaller fragments move faster through the gel compared to larger ones.

• Answer: (1) Agrobacterium tumefaciens
• Explanation: Agrobacterium tumefaciens is a bacterium that is widely used for gene transfer in plants. It naturally transfers a portion of its DNA (T-DNA) into the plant genome, making it a “natural genetic engineer.”

• Answer: (4) All of the above
• Explanation: Bioinformatics integrates computational tools to analyze data in genomics, proteomics, and drug discovery.

• Answer: (2) Bacillus thuringiensis
• Explanation: Bt cotton is genetically modified to express a toxin from Bacillus thuringiensis that is lethal to specific insect pests.

• Answer: (4) All of the above
• Explanation: Techniques like RNAi, gene knockout, and antisense RNA prevent the expression of specific genes, silencing them.

• Answer: (2) Reverse transcriptase
• Explanation: Reverse transcriptase synthesizes complementary DNA (cDNA) from mRNA, commonly used in molecular cloning and gene expression studies.

• Answer: (1) Penicillin
• Explanation: Secondary metabolites like penicillin are not directly involved in growth or reproduction but serve ecological functions.

• Answer: (2) Cystic fibrosis
• Explanation: Gene therapy introduces a functional gene to correct genetic defects, such as those causing cystic fibrosis.