NEET BIOLOGY

Detailed explanation-1: -Restriction endonucleases (REs) are bacterial enzymes that cleave double-stranded DNA. Type I REs are important in bacterial function but do not cleave DNA at specific sequences.

Detailed explanation-2: -SmaI is an example of a restriction enzyme that cuts straight through the DNA strands, creating DNA fragments with a flat or blunt end. Other restriction enzymes, like EcoRI, cut through the DNA strands at nucleotides that are not exactly opposite each other.

Detailed explanation-3: -Restriction Fragment Length Polymorphisms However, these enzymes are able to cut human DNA like other kinds of DNA, and they do this by recognizing a particular DNA sequence that they then cut. Thus these enzymes can recognize and localize certain DNA sequences, usually of four to eight base pairs.

Detailed explanation-4: -Scientists mix the gene and the opened vector together with a bacterial enzyme called DNA ligase. The ligase sticks DNA ends together to form a single circular molecule that includes both the vector and the gene.