NEET Biotechnology and Its Applications Test

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

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

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

• 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: (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: (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: (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: Gene therapy faces challenges like immune responses, limitations in treating complex disorders, and high costs.

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

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

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

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

• 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: Bioinformatics integrates computational tools to analyze data in genomics, proteomics, and drug discovery.

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

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

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

• 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) 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 separates DNA fragments based on size using an electric field.

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

• 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: Biofertilizers like Rhizobium, Azotobacter, and Mycorrhiza enhance soil fertility by fixing nitrogen or improving nutrient absorption.

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

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

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

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

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

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

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