Final answer:
Histone acetylation affects nucleosome mobility and positioning on DNA.
Step-by-step explanation:
One way in which nucleosomes can be modified is by changing their composition. Histone variants, like histone acetylation, affect nucleosome mobility and positioning on DNA.
Modifications to histones (the proteins that make up nucleosomes) can alter their physical characteristics and impact how tightly DNA is wound around them. One such modification is histone acetylation, which involves the addition of acetyl groups to specific amino acids in histones. This modification reduces the positive charge of histones, loosening their interaction with DNA and allowing for increased nucleosome mobility and repositioning on the DNA.