What is a consequence of the lagging strand's lack of a 3' -OH end?

The correct answer is that the lagging strand's lack of a 3' -OH end leads to shorter DNA after repeated rounds of replication. This occurs because DNA replication requires a primer to initiate synthesis, which provides the necessary 3' -OH group for new nucleotides to attach. The lagging strand is synthesized in short segments called Okazaki fragments, each of which is initiated by an RNA primer. As the replication process continues, the primers are eventually removed and replaced with DNA. However, when the RNA primers are removed from the 5' ends of these fragments, there isn't a 3' -OH on the adjacent fragment to fill in that gap, resulting in a portion of DNA unable to be synthesized.

This cumulative loss during multiple replication cycles leads to telomere shortening, which is a characteristic of cellular aging. Hence, the overall consequence of this mechanism is a gradual shortening of the DNA strand with each successive replication, particularly affecting the ends of linear chromosomes, as they cannot be fully replicated without sufficient 3' -OH ends.