A piece of DNA that is 3 kb in length is found in many locations throughout the genome.How would you decide whether this was a LINE or a DNA transposon?
A) If it has more than 10,000 copies in the genome,it is a LINE;if not,it is a DNA transposon.
B) If it has more than 10,000 copies in the genome,it is a DNA transposon;if not,it is a LINE.
C) If it contains the sequence GCTCGATC it is a LINE;if not,it is a DNA transposon.
D) If it uses an RNA intermediate,it is a LINE;if not,it is a DNA transposon.
E) If it is transcribed,then it must be a LINE;if not,then it is a DNA transposon.

Question

Quizplus · Accepted Answer

This question is asking us to differentiate between a LINE (long interspersed nuclear element) and a DNA transposon. One way to differentiate them is by the mechanism they use to move around the genome. LINEs use an RNA intermediate, whereas DNA transposons do not. Therefore, if the 3 kb DNA sequence uses an RNA intermediate, then it must be a LINE. This is the best choice. The other options are not accurate. The number of copies in the genome does not determine whether it is a LINE or DNA transposon. The presence or absence of a specific sequence (GCTCGATC) is not enough to make a determination. Similarly, transcribing a sequence does not necessarily mean that it is a LINE.

A Piece of DNA That Is 3 Kb in Length