Questions: A double stranded stretch of eukaryotic DNA is 250,000 bp long. If the average linker is about 54 base pairs, how many nucleosomes would be present on this piece of DNA? Multiple Choice O 1250 O 200 O 1712 O 4630 < Prev 23 of 61 Next >

The answer is the third one (C): 1712.

Explanation: To determine the number of nucleosomes on a piece of eukaryotic DNA, we need to consider the length of DNA wrapped around each nucleosome and the length of the linker DNA between nucleosomes.

1. Each nucleosome core particle consists of about 146 base pairs of DNA wrapped around histone proteins.
2. The average linker DNA between nucleosomes is given as 54 base pairs.

Therefore, the total length of DNA associated with one nucleosome (including the linker) is: 146 bp (nucleosome core) + 54 bp (linker) = 200 bp

Given the total length of the DNA is 250,000 base pairs, we can calculate the number of nucleosomes by dividing the total length by the length associated with one nucleosome: 250,000 bp / 200 bp per nucleosome = 1250 nucleosomes

However, this calculation seems to contradict the provided options. Let's re-evaluate the calculation:

If we consider the total length of DNA and the average linker length, we should use the formula: Number of nucleosomes = Total DNA length / (Length of DNA per nucleosome + Linker length)

So, the correct calculation should be: Number of nucleosomes = 250,000 bp / (146 bp + 54 bp) Number of nucleosomes = 250,000 bp / 200 bp Number of nucleosomes = 1250

Upon re-evaluation, the correct answer is indeed 1250, which matches the first option.

Therefore, the correct answer is the first one (A): 1250.