# Calculating Copy Number of a Human Genome

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da_charmed_girl
Calculating Copy Number of a Human Genome

Hi!
This may sound like a stupid question but I was wondering how would you calculate the copy number of a human diploid genome and calcualte the proportion at which the sequence occupies the genome. This is the information I was given:

haploid human genome: 3x10^9
length of repetitive sequence: 35bp
number of times present: 150,000 times

Thanks!!! :)

Arvind Singh Pundir
Hi

Hi

Hi da_charmed_girl,
The answer to your question depends on what you are looking for. As you pointed out a haploid human genome is 3x10^9 bp. A single gene, regardless of its size, will be present as a single copy in this genome. Yet, if you are looking for how much that DNA represents relative to the size of the genome, then the larger the gene the larger the proportion of the genome it covers. In your case, if you multiple 35 bp by 150,000 copies you get 5.25x10^6 bp, which is about 0.175% of the genome.
Copy number usually refers to the number of copies of a particular sequence in a genome. For example there are 5 to 7 copies of the 16S sequence in a typically E. coli genome. In your case if are looking for copy number, then you already have your answer: 150,000 copies.

da_charmed_girl
Thank you for your help!! I

Thank you for your help!! I got the same answer, it just seemed like it was too easy. Thank you again! :)