Principles And Processes Of Biotechnology

Ligase is an enzyme that is specifically used for joining or sealing two DNA fragments together. It plays a crucial role in DNA replication, repair, and recombination processes. Ligase catalyzes the formation of phosphodiester bonds between the adjacent nucleotides of DNA strands, resulting in the formation of a continuous DNA molecule. Therefore, the correct answer is joining two DNA fragments.

Restriction endonuclease is the correct answer because it is an enzyme that cuts DNA at specific recognition sites. This enzyme is commonly used in molecular biology research to manipulate and study DNA. DNA ligase is responsible for joining DNA fragments together, DNA polymerase is involved in DNA replication, and reverse transcriptase is an enzyme used to generate complementary DNA (cDNA) from RNA templates.

Gel electrophoresis is a technique used to separate DNA fragments based on their size. It involves placing the DNA sample on a gel matrix and applying an electric field. Since DNA is negatively charged, it moves towards the positive electrode. Smaller fragments move faster and travel further through the gel, while larger fragments move slower and stay closer to the starting point. This separation allows scientists to analyze and study the different sizes of DNA fragments, which can provide valuable information about genetic variations or mutations.

Genetic engineering refers to the process of improving an organism's genotype by introducing foreign genes. This technique allows scientists to manipulate an organism's genetic material to enhance desired traits or introduce new characteristics. Through genetic engineering, genes from one organism can be inserted into another, resulting in the production of genetically modified organisms (GMOs). This process has wide-ranging applications in various fields, including agriculture, medicine, and environmental conservation.

Agrobacterium tumefaciens is a bacterium that is commonly used in genetic engineering work in plants. It has the ability to transfer a piece of its own DNA, known as T-DNA, into the genome of a plant cell. This characteristic makes it a valuable tool for introducing new genes into plants. By manipulating the T-DNA, scientists can insert desired genes into the plant's genome, allowing for the production of genetically modified plants with specific traits or characteristics. This bacterium has been extensively studied and utilized in plant biotechnology due to its natural ability to transfer DNA to plants.

Endonucleases are enzymes that cleave DNA molecules at specific sites within the DNA sequence. They act like "chemical knives" by cutting the DNA at specific points, allowing for the manipulation and modification of DNA molecules. Ligases, polymerases, and transcriptases are also enzymes involved in DNA processes, but they do not specifically function as "chemical knives" like endonucleases do.

Polymerase chain reaction (PCR) is a laboratory technique used to amplify a specific DNA sequence. It is a powerful tool in molecular biology and is commonly used for various applications such as DNA cloning, genetic testing, and forensic analysis. PCR allows for the rapid and efficient amplification of a small amount of DNA into a larger amount, making it highly useful in DNA amplification. It does not play a direct role in protein synthesis or amino acid synthesis.

Taq polymerase is the correct answer because it is the enzyme commonly used in the polymerase chain reaction (PCR). PCR is a technique used to amplify DNA, and Taq polymerase is a heat-stable DNA polymerase derived from the thermophilic bacterium Thermus aquaticus. It is able to withstand the high temperatures required for denaturation and annealing of DNA during the PCR process. Taq polymerase is widely used in molecular biology research and diagnostics due to its stability and ability to efficiently amplify DNA.

DNA ligase is an enzyme that is responsible for joining the ends of DNA fragments together. In the context of the question, the linking of an antibiotic gene with a plasmid vector requires the joining of the two DNA fragments. DNA ligase facilitates this process by catalyzing the formation of phosphodiester bonds between the fragments. Exonuclease, endonucleases, and DNA polymerase are not directly involved in the joining of DNA fragments and therefore cannot be the correct answer.

pBR 322 is the correct answer because it is the only option that is a plasmid. Eco RI, AIUI, and Hind II are all restriction enzymes, not plasmids. Plasmids are small, circular DNA molecules that exist separately from the chromosomal DNA and can replicate independently. pBR 322 is a commonly used plasmid in molecular biology research, making it the correct choice among the given options.

Eco RI is a restriction enzyme that recognizes and cleaves DNA at specific sequences. The given sequence "GAATTC" is the recognition sequence for Eco RI. When Eco RI encounters this sequence, it cuts the DNA at the specific site, resulting in two fragments. Therefore, GAATTC is the correct answer.

Recombinant DNA technology can be used to produce large quantities of biologically active form of Interferon in E. coli. Interferon is a protein that is naturally produced by the immune system in response to viral infections. By using recombinant DNA technology, the gene encoding for Interferon can be inserted into E. coli bacteria, which can then be grown in large quantities in a laboratory setting. This allows for the production of large amounts of Interferon, which can be used for various medical purposes, such as treating viral infections and certain types of cancer.

Kary Mullis is the correct answer because he was a biochemist who won the Nobel Prize in Chemistry in 1993 for his invention of the polymerase chain reaction (PCR) method. PCR is a technique used to amplify a specific DNA sequence, and it revolutionized the field of molecular biology and genetic research. Wilmut, Jeffreys, and Eithoven are not associated with the development of PCR or significant contributions to molecular biology.

Restriction endonucleases are enzymes that cut DNA at specific recognition sequences. They are commonly used in recombinant DNA technology to create recombinant DNA molecules. These enzymes are obtained from bacterial cells, specifically from bacteria that have a defense mechanism against bacteriophages. Bacterial cells produce restriction endonucleases to protect themselves from viral DNA. Therefore, the correct answer is bacterial cell.

Restriction endonucleases are enzymes that can cut DNA at specific sites. These enzymes can be purified from bacteria and used in vitro, meaning outside of a living organism. This ability to cut DNA at specific sites allows scientists to manipulate and modify DNA sequences, which is the basis of genetic engineering. Therefore, the fact that restriction endonucleases can be purified from bacteria and used in vitro is a key reason why genetic engineering is possible.