Final answer:
Telomerase extends the telomeric DNA on the lagging strand to compensate for the inability of DNA polymerase to replicate the very ends of linear chromosomes, hence preventing the shortening of chromosomes during cell division. Option 1 is correct.
Step-by-step explanation:
The telomeric sequence is added to the end of a chromosome by an enzyme called telomerase, which functions primarily to prevent the shortening of chromosomes during cell division.
During DNA replication, the leading strand is synthesized continuously, but the lagging strand is synthesized in short segments. Near the end of the lagging strand, there isn't a place for a primer to initiate synthesis of the final segment, leading to progressively shorter telomeres with each replication cycle.
Telomerase, with its built-in RNA template, extends the telomeres, ensuring that DNA polymerase can complete the replication of the lagging strand without loss of genetic data.
Therefore, the telomerase does not serve to mask the chromosomal end, initiate or terminate transcription, or replicate the leading strand. Its correct function is to extend the telomeric DNA of the lagging strand to compensate for the inability of DNA polymerase to completely replicate the ends of linear chromosomes.