Final answer:
Transposable elements, or transposons, are DNA segments that can be used as genetic markers to locate genes they insert into, causing mutations. They move through transposition, either by 'cut-and-paste' or 'replicative' methods, and can alter gene function, affecting the cell's phenotype.
Step-by-step explanation:
A well characterized transposable element can be used as a genetic marker to locate the gene into which it has inserted to generate a mutation. Transposable elements, or transposons, are molecules of DNA that can excise from one location in a DNA molecule and integrate into another location, a process known as transposition. This ability to move can be used to track where the transposon has inserted within the genome, which can disrupt or alter the function of genes, thereby causing mutations. Two main mechanisms by which transposons can move include the cut-and-paste and replicative transposition methods. The significant characteristic of these elements is that they encode for the enzyme transposase, which facilitates their movement within the genome. Transposons can affect the phenotype of a cell by either inactivating a gene when they insert within it or by causing genetic recombination.