Recombinant Dna Technology And Applications

• Endonuclease (I): These enzymes are crucial for cutting DNA at specific sites. They are used to cut both the bacterial gene and the plasmid vector to insert the gene of interest.
• Ligase (II): This enzyme is used to join the DNA fragment (the bacterial gene) to the plasmid or vector, completing the recombinant DNA.
• Agrobacterium tumefaciens (III): This bacterium is often used in plant genetic engineering, but not in cloning genes into animal cells. Therefore, it's not required for cloning a bacterial gene in animal cells.
• Microinjection (IV): This technique involves directly injecting foreign DNA into animal cells and is widely used in genetic engineering.
• Gene gun (V): The gene gun is a tool used to transfer DNA into cells by shooting microscopic gold or tungsten particles coated with DNA into the cells. This technique is not typically used for animal cells.
• Lysozyme (VI): Lysozyme can be used to break down the cell walls of bacteria, which is useful when extracting DNA, especially from bacterial cells.
• Cellulase (VII): Cellulase is used to break down plant cell walls and isn't necessary for the cloning of bacterial genes into animal cells.
• Electrophoresis (VIII): This technique is used to separate DNA fragments by size, which is important for verifying the DNA before and after the cloning process.

Thus, the correct tools for cloning a bacterial gene into animal cells are I, II, IV, VI, and VIII, making option (C) the correct choice.

The enzyme required to cleave a plasmid is Endonuclease.

(A) Ligase - Incorrect: DNA ligase joins DNA fragments, it doesn't cut them.

(B) Endonuclease - Correct: Restriction endonucleases (like EcoRI) cut plasmid DNA at specific recognition sites.

(C) Exonuclease - Incorrect: These remove nucleotides from DNA ends, not make internal cuts.

(D) Polymerase - Incorrect: DNA polymerase synthesizes DNA, it doesn't cleave it.

The correct answer is (B) Endonuclease, specifically restriction enzymes that create "sticky ends" for recombinant DNA technology.