The nuclear genome of a single human cell (i.e., the entire diploid complement)contains about 6.6 billion (6.6 × 10⁹)base pairs of DNA.If synthesis at each replication fork occurs at an average rate of 50 nucleotides per second, all the DNA is replicated in 5 minutes.Assume that replication is initiated simultaneously at all origins.How many origins of replication exist in a human diploid genome? A)220, 000 B)440, 000 C)880, 000 D)2)64 × 10⁷ E)1)32 × 10⁸

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The total length of DNA in a human diploid genome is 6.6 × 10⁹ base pairs. If replication occurs at an average rate of 50 nucleotides per second, it will take 5 minutes to replicate the entire genome. Since replication is initiated simultaneously at all origins, the number of origins of replication can be calculated as follows:Number of origins = Total length of DNA / (Rate of replication × Time taken)= 6.6 × 10⁹ base pairs / (50 nucleotides/second × 5 minutes × 60 seconds/minute)= 220,000 origins

The Nuclear Genome of a Single Human Cell (I