Recall that the human genome contains roughly 3 billion base pairs per haploid genome and that about 25% of the human genome is associated with genes, including introns and regulatory sequence. What would be the approximate average length of DNA per human gene if the genome contained 20,000 genes?

• A. 1,000 base pairs
• B. 10,000 base pairs
• C. 20,000 base pairs
• D. 80,000 base pairs
• E. 40,000 base pairs

Answer: (E)

Verified step by step guidance

1. First, identify the total number of base pairs in the human genome. The human genome contains approximately 3 billion base pairs per haploid genome.
2. Next, determine the portion of the genome associated with genes. It is given that about 25% of the human genome is associated with genes, including introns and regulatory sequences.
3. Calculate the total number of base pairs associated with genes by multiplying the total number of base pairs by the percentage associated with genes: \( 3,000,000,000 \times 0.25 \).
4. Now, divide the total number of base pairs associated with genes by the number of genes to find the average length of DNA per gene. The genome contains 20,000 genes.
5. Perform the division: \( \frac{\text{Total base pairs associated with genes}}{20,000} \) to find the average length of DNA per human gene.