Question

Which of the following statements about transposable genetic elements is NOT true?
A. Some use an RNA intermediate.
B. They can cause mutations by inserting into genes.
C. They all use a cut and paste mechanism.
D. They are present in multiple copies in the genome.

Answer 1

Answer:

C. They all use a cut and paste mechanism.

Explanation:

DNA transposons can go through a replicative or nonreplicative transposition.

The replicative transposition uses a "copy and paste" mechanism that consists of the introduction of a new copy of the transposable element in a new position, meanwhile the old copy remains in the original position. This determines an increase in the number of copies.

The nonreplicative transposition uses a "cut and paste" mechanism that consists of the cleavage of the transposable element from its position and its insertion in a new position without increasing the number of copies.

Retrotransposons, on the other side, move through RNA intermediates generated by the reverse transcriptase.