Question #da84f
1 Answer
Sep 5, 2015
Histones are a family of proteins that are associated with with DNA in the nucleus.
Explanation:
The histones consist mostly of lysine and arginine, so they are positively charged.
This makes then strongly attracted to DNA, which is negatively charged.
The ionic attractions enable the DNA to become tightly packed about the histones.
(from en.wikipedia.org)
The DNA molecules wrap around histone octamers to make nucleosomes.
(from www.mun.ca)
The nucleosomes fold up to form fibres that are compressed and folded until they are tightly coiled into a strand of a chromosome.
The result is that the 1.8 m of DNA in each human cell is condensed into a length of about 120 µm in the chromosomes.
Here is a video on the role of histones in the packaging of DNA.
