If a strand of DNA underwent four rounds of replication what percentage of the total DNA present would be comprised of the original DNA molecule?

Answer 1

DNA is doubled stranded / / (original). | = replicated.

First round of replication, the DNA splits and the replicated DNA is made up of the original and new DNA. One strand produces 2 stands.

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One round, the percentage of original DNA would be 50%. (2 strands out of 4)

Second round you get..because each stand again produces 2 stands.

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Third round..

/| /|

4th round..

--> /| --> /|

So 2/16 = 1/8

2 of the 16 DNA strands contain original DNA.

Answer 2

After four rounds of replication, the original DNA molecule would account for 6.25% of the total DNA present. This is because each round of replication doubles the amount of DNA, resulting in 2^n (n represents the number of replications) total DNA molecules, with each original molecule contributing to 1/2^n of the total.