NEET Biotechnology and Its Applications Test

• 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: (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: (4) All of the above
• Explanation: Selectable markers such as antibiotic resistance genes, fluorescent proteins, and reporter genes are used to identify cells that have successfully incorporated foreign DNA.

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

• 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: (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: (4) All of the above
• Explanation: Transgenic animals serve in research, medicine, and agriculture for studying genes, creating therapies, and disease modeling.

• Answer: (1) PCR
• Explanation: Polymerase Chain Reaction (PCR) is used to amplify specific DNA sequences rapidly.

• 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: (3) DNA ligase
• Explanation: DNA ligase is referred to as the molecular glue because it joins DNA fragments by forming phosphodiester bonds.

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

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

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

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

• 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) Vitamin A
• Explanation: Golden rice is genetically modified to produce β-carotene, a precursor of vitamin A, to combat vitamin A deficiency in populations with limited access to this nutrient.

• Answer: (2) Oncomouse
• Explanation: The Oncomouse was genetically modified to carry an activated oncogene, making it a model for cancer research.

• 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: (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: (1) Extraction, Amplification, Ligation, Transformation
• Explanation: The typical steps in gene cloning include extracting the DNA, amplifying the gene of interest, ligating it into a vector, and transforming it into a host organism for replication.

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

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

• Answer: (1) Polymerase Chain Reaction
• Explanation: PCR is a technique used to amplify specific DNA sequences, making millions of copies of a particular segment of DNA in a short time.

• 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: These methods are commonly used in genetic engineering to introduce DNA into cells for transformation.

• Answer: (2) Vitamin A deficiency
• Explanation: Golden rice contains β-carotene, which the body converts into vitamin A, addressing vitamin A deficiency in developing countries.

• Answer: (2) Convert RNA into DNA
• Explanation: Reverse transcriptase synthesizes complementary DNA (cDNA) from an RNA template, commonly used in gene expression studies.

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

• Answer: (2) They transfer genes into plants.
• Explanation: Ti plasmids, derived from Agrobacterium tumefaciens, are used in plant genetic engineering to transfer genes into plant cells.

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

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

• Answer: (2) Join DNA fragments
• Explanation: DNA ligase seals the nicks in the sugar-phosphate backbone of DNA, joining fragments together.

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

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