PROBLEMS Which statements are true? Explain why or why not 51 The majority of cells in your body have exactly the same nucleotide sequence in their genomes. 52 In a replication bubble, the same parent DNA strand serves as the template strand for leading-strand synthesis at one replication fork and as the template for lagging-strand synthesis at the other fork. 53 In E. coli, where the replication fork travels at 500 nucleotide pairs per second. the DNA ahead of the fork-in the absence of topoisomerase-would have to rotate at nearly 3000 revolutions per minute. 5-4 When bidirectional replication forks from adjacent origins meet, a leading strand always runs into a lagging strand. 55 DNA repair mechanisms all depend on the cell having two homologous chromosomes.

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