Suppose you add fluorescent ribonucleotides to a cell undergoing DNA replication so that the RNA primers used in DNA synthesis glow when viewed with a fluorescent microscope. You notice that, near each replication fork, one strand glows more than the other. Which strand is it that glows more, and why?
A)The leading strand glows more because it is elongated nearest the replication fork.
B)The leading strand glows more because it forms the "trombone loop."
C)The lagging strand glows more because its RNA primer is nearer the replication fork.
D)The lagging strand glows more because it forms the "trombone loop."

Question

Quizplus · Accepted Answer

The lagging strand glows more because its RNA primer is nearer the replication fork. This is due to the fact that the lagging strand is synthesized in short segments (Okazaki fragments), each starting with a new RNA primer, whereas the leading strand is synthesized continuously.

Suppose You Add Fluorescent Ribonucleotides to a Cell Undergoing DNA