Practice question

Autonomous transposable elements encode enzymes required for own movement within element boundaries. DNA transposons encode transposase that recognizes terminal inverted repeats and catalyzes cut-and-paste excision, while autonomous retrotransposons such as LINE-1 and LTR elements encode reverse transcriptase, endonuclease, and integrase activities. Possession of intact open reading frames, promoters, and cis-acting terminal sequences allows independent transposition without helper. Expression levels, tissue specificity, and post-translational modifications determine transposition frequency and potential for insertional mutagenesis in germline. This principle illustrates essential molecular mechanisms governing replication fidelity and mutation fixation relevant for exam interpretation.