What happens on gene level, that makes DNA shorter with each replication?

Question

I know that it has to do something with primers and the whole anabolic process of replication, but how? What happens that makes DNA shorter with each replication? Is RNA-primers getting cut off with DNA? Explain like i am five

In: 20

Answer 1

My understanding is that the telomers get shortened with each replication as a result of the inability to form the final Okazaki fragment in the lagging strand. If you visualize replication of the lagging strand, the RNA primer needs to affix to the Strand a certain number of bases down from where the last okazaki fragment annealed into place. If there is not enough length to the strand, there is not enough room for the replication machinery to properly replicate the remaining nucleotides of the lagging strand, causing the telomers to shorten with every replication.