複選題5. Which of the following statements about transposon are correct? (A) Transposon is a DNA sequence that can irreversibly change its position within a genome. (B) Transposition often results in duplication of the same genetic material. (C) The reverse transcription step of retrotransposon is catalyzed by a reverse transcriptase, which is often encoded by the transposon itself. (D) Dissociation elements (Ds) is an example of an autonomous transposon, and activator element (Ac) is an example of a non-autonomous transposon. Without Ds, Ac is not able to transpose. (E) Transposition of Ds was sometimes accompanied by major chromosomal rearrangements including deletions, duplications, inversions, reciprocal translocations.