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) Count the number of copies in the genome. If it has more than 10,000 copies, it is a LINE; if not, it is a DNA transposon.
B) Count the number of copies in the genome. If it has more than 10,000 copies, 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 uses a copy and paste mechanism of copying, it is a DNA transposon; if not, it is a LINE.

Question

Quizplus · Accepted Answer

The question asks how to decide between whether the DNA sequence is a LINE or a DNA transposon. The primary distinguishing feature between these two types of mobile genetic elements is the mechanism by which they transpose. LINEs use an RNA intermediate, while DNA transposons use a cut and paste mechanism. Therefore, the best way to decide between the two is to determine whether the insertion uses an RNA intermediate, which would make it a LINE. Counting the number of copies or looking for specific sequences is not sufficient to classify the insertion as a LINE or a DNA transposon.

A Piece of DNA That Is 3 Kb in Length