Final answer:
Cells have mechanisms to alter DNA in regions of the genome where transposable elements are common to block production of transposase and inhibit transposition. This can be achieved by accumulating transposons in non-coding regions, rendering transposons inactive through mutations, and using small interfering RNAs to target and destroy transposon transcripts.
Step-by-step explanation:
Transposable elements, also known as transposons or jumping genes, are segments of DNA that can move from one location to another in the genome. Cells have mechanisms to alter DNA in regions where transposable elements are common in order to block the production of transposase, which is the enzyme responsible for transposition. This inhibition of transposition helps prevent genetic damage caused by excessive transposon activity.
One way cells block transposition is by accumulating transposons in non-coding regions of the genome, which make up the majority of the DNA. Transposons that integrate into these non-coding regions have minimal impact on the cell's phenotype. Another mechanism involves mutations that render transposons inactive over time, either by disrupting the gene responsible for transposition or by mutations at the ends of the transposons themselves.
Additionally, cells can use small interfering RNAs (siRNAs) to target and destroy transposon transcripts, preventing their translation into functional enzymes. This RNA interference mechanism helps to silence transposons after their transposition has occurred, further reducing the risk of genetic damage.