Final answer:
ORF2 in LINE elements encodes the reverse transcriptase and an integrase activity essential for transposition of the LINE.
Step-by-step explanation:
ORF2 in LINE elements encodes the reverse transcriptase and an integrase activity essential for transposition of the LINE. It is a part of the gene structure of LINES (Long Interspersed Nuclear Elements), which are non-LTR retrotransposons.
These elements do not have long terminal repeats but have 5' and 3' untranslated regions (UTRs) flanking the ORFs.