Genomic DNA from the nematode worm Caenorhabditis elegans is organized by nucleo

Question

Genomic DNA from the nematode worm Caenorhabditis elegans is organized by nucleosomes in the manner typical of eukaryotic genomes, with 145 bp encircling each nucleosome and approximately 55 bp in linker DNA When C elegans chromatin is carefully isolated, stripped of nonhistone proteins, and placed in an appropriate buffer, the chromatin decondenses to the 10-nm fiber structure Suppose researchers mix a sample of 10-nm-fiber chromatin with a large amount of the enzyme DNase I that randomly cleaves DNA in regions that are not protected by bound protein. Next, they remove the nucleosomes, separate the DNA fragments by gel electrophoresis, and stain the fragments by ethidium bromide. What size DNA fragment do you expect to see in the stained electrophoresis get assuming all unprotected DNA was cleaved?

Explanation / Answer

The linker DNA is the region, which is not protected by nucleosomes. So, when chromatin is cleaved with DNase I, then the linker DNA is cleaved.

Hence, the correct option is 145 bp.

145 bp around the nucleosomes are the protected DNA areas.

Related Questions

Navigate

• Browse (All)
• Browse G
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.