AP BIOLOGY

Detailed explanation-1: -A long terminal repeat (LTR) is a pair of identical sequences of DNA, several hundred base pairs long, which occur in eukaryotic genomes on either end of a series of genes or pseudogenes that form a retrotransposon or an endogenous retrovirus or a retroviral provirus.

Detailed explanation-2: -The long terminal repeat (LTR) retrotransposons, one of the main groups of retroelements (which include both LTR and non-LTR retrotransposons as well as retroviruses), are among the most abundant constituents of eukaryotic genomes.

Detailed explanation-3: -Long terminal repeat (LTR) retrotransposons make up a large fraction of the typical mammalian genome. They comprise about 8% of the human genome and approximately 10% of the mouse genome. On account of their abundance, LTR retrotransposons are believed to hold major significance for genome structure and function.

Detailed explanation-4: -LTR retrotransposons are class I transposable element characterized by the presence of long terminal repeats (LTRs) directly flanking an internal coding region. As retrotransposons, they mobilize through reverse transcription of their mRNA and integration of the newly created cDNA into another location.