Final answer:
Site-specific recombination involves the exchange of DNA segments at specific recognition sites, facilitated by restriction enzymes and DNA ligase. This process introduces genetic variability and can provide information about the proximity of genetic markers on a chromosome.
Step-by-step explanation:
Site-specific recombination occurs between specific DNA sequences that share a set of common sequence motifs or recognition sites. These sites are recognized by certain enzymes, which facilitate the exchange of DNA segments between these specific locations.
For instance, during the process of replicative transposition, a transposon at the original location (donor site) can be copied to a new insertion-site location in the genome. This mechanism often involves a recombination event that includes the use and coordination of restriction enzymes and DNA ligase. The restriction enzymes cut the DNA at specific sequences, while DNA ligase joins the DNA segments together after the recombination process.
Recombination introduces genetic variability, which is crucial for evolution and adaptation. The frequency of recombination between two genetic markers can also give insights into the physical distance between them on a chromosome, as markers that are closer together are less likely to be separated by recombination events during meiosis.