Without that structure, no mask could be created, of course, and the staggered ends would thus be exposed. As you know, exposed staggered ends would mean the death of the cell. All of a sudden, things began to make sense. The cell culture data could actually be explained in biochemical terms, and telomeres would vault to the very front of the effort to understand the molecules of aging. The insight could be divided into three steps.
Cells replicate in a dish.
With every round of replication, their tips grow shorter. The mask reforms with every round of replication for a time, and the cells live. A critical length is eventually reached whereby there are not enough telomeres to form the mask. Eventually, there is a round of replication in which the ends of the chromosomes do not make the paper clip structure. The staggered ends now lie exposed, and the cell begins accumulating damage.