Difficulty: Easy
Correct Answer: Eukaryotic chromosomes have multiple origins of replication
Explanation:
Introduction / Context:
Genome size and chromatin organization impose distinct constraints on replication strategies in eukaryotes versus prokaryotes. Understanding origin usage and replisome dynamics is fundamental to cell biology and biotechnology.
Given Data / Assumptions:
Concept / Approach:
The hallmark difference is origin usage: eukaryotic chromosomes fire many origins to complete S phase efficiently, while most bacteria use one (or very few) origins per chromosome, commonly oriC, with two forks moving bidirectionally.
Step-by-Step Solution:
Verification / Alternative check:
DNA combing and replication timing maps in eukaryotes reveal origin clusters; bacterial replication proceeds bidirectionally from oriC, supporting the stated difference.
Why Other Options Are Wrong:
Common Pitfalls:
Assuming primer independence for eukaryotes or conflating number of polymerases with speed.
Final Answer:
Eukaryotic chromosomes have multiple origins of replication
Discussion & Comments