DNA replication Original Scenario-Based Practice

Questions

1. 1.

   In an advanced bio-foundry, genetic architects design an artificial replisome to duplicate synthetic chromosomes containing antiparallel template strands. As the synthetic helicase unzips the parental duplex along a single directional axis, molecular sensors reveal that polymerization proceeds smoothly and continuously on one template, whereas the opposite template requires repeated cycles of priming and discontinuous backward elongation. Which fundamental property of DNA polymerases necessitates this discontinuous mode of synthesis on the lagging strand?

   • A) DNA polymerases initiate polymerization de novo across both strands without requiring an existing 3'-OH group.
   • B) DNA polymerases read parental template strands exclusively in the 5' to 3' direction to synthesize in the 3' to 5' direction.
   • C) DNA polymerases require topoisomerase to supply continuous ribonucleotide primers along both unwinding strands.
   • D) DNA polymerases can only attach incoming deoxynucleotides to a free 3'-OH group, restricting chain growth to the 5' to 3' direction.

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