NEET Biotechnology and Its Applications Test

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

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

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

• Answer: (2) Exploitation of biological resources without permission
• Explanation: Biopiracy occurs when companies or researchers use indigenous biological resources without proper authorization or compensation.

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

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

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

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

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

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

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

• 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) 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: (4) All of the above
• Explanation: These crops were genetically engineered for specific purposes: pest resistance (Bt cotton), enhanced nutrition (Golden rice), and extended shelf life (Flavr Savr tomato).

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

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

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: (2) Vector for gene transfer
• Explanation: The Ti plasmid from Agrobacterium tumefaciens is used as a vector to transfer genes into plant cells, particularly for creating genetically modified plants.

• 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: Various methods, including electroporation, gene guns, and microinjection, are used to create genetically modified plants by introducing foreign genes into plant cells.

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

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

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

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

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

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

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

• 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: (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
• 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: (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: (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: Selectable markers such as antibiotic resistance genes, fluorescent proteins, and reporter genes are used to identify cells that have successfully incorporated foreign DNA.

• 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.