AtoZExams

Biotechnology Multiple Choice Questions 1) The restriction endonuclease has a defense mechanism in the bacterial system against foreign DNA such as viruses. But how can it protect its DNA? precisely in the middle of the chain anywhere in the chain the ends of the chain only within the polynucleotide chain, not at the ends  Answer: D [only within the polynucleotide chain, not at the ends] Description: The cleavage is done within the polynucleotide chain and not at the ends. The enzyme which cuts the sequence at the ends is known as an exonuclease. 2) The restriction endonuclease has a defense mechanism in the bacterial system against foreign DNA such as viruses. But how can it protect its DNA? By methylation of bacterial DNA by restriction enzyme By methylation of foreign DNA by restriction enzyme By phosphorylation of bacterial DNA by restriction enzyme By phosphorylation of foreign DNA by restriction enzyme  Answer: A [ By methylation of bacterial DNA by restriction enzyme ] ...