What problem arises when there is not enough template strand at the end of a telomere?

What problem arises when there is not enough template strand at the end of a telomere?

• A. DNA polymerase cannot synthesize
• B. Primase cannot attach
• C. Helicase cannot unwind
• D. Ligase cannot seal

Answer: (B)

Primase is needed to lay down RNA primers that start DNA synthesis on the lagging strand. At the very end of a telomere, there isn’t enough template DNA for primase to copy and create a primer. Without that primer, DNA polymerase has nothing to extend, so replication cannot proceed for the final segment. In short, primase cannot attach because there’s no adequate template for primer creation. The other enzymes wouldn’t fix this specific end-replication issue: helicase unwinds, polymerase needs a primer to start, and ligase seals after synthesis, but none can initiate synthesis without a primer.

Primase is needed to lay down RNA primers that start DNA synthesis on the lagging strand. At the very end of a telomere, there isn’t enough template DNA for primase to copy and create a primer. Without that primer, DNA polymerase has nothing to extend, so replication cannot proceed for the final segment. In short, primase cannot attach because there’s no adequate template for primer creation. The other enzymes wouldn’t fix this specific end-replication issue: helicase unwinds, polymerase needs a primer to start, and ligase seals after synthesis, but none can initiate synthesis without a primer.