(a) Draw a labelled diagram nucleosome.
(b) What is histone?
(c) In eukaryotes the DNA molecules are organised within the nucleus. How is the DNA molecules are organised within the nucleus. How is the DNA molecules organised in a bacterial cell in absence of a nucleus?

(a)  
(b) Histone is a type of basic protein on which DNA wrapped around it. Histone is a octamer unit. There are four types of histones, named: H2A, H2B, H3, and H4.Octomers of two of each type of histone form nucleosomes. These nucleosomes are wrapped together in a spiral structure called a solenoid. Additional H1 proteins are associated with each nucleosome as links to maintain the overall chromatin structure.

 
(c) In a bacterial cell, in the absence of nucleus DNA molecule attached to the proteins leads to formation of nucleoid. In case of eukaryotes genetic material organised as chromosomes with the help of packaging . DNA wrapped around histone octamer, part of DNA which is wrapped around histone octamer is core DNA and the part of DNA which connects two octamers is linker DNA . Core DNA +linker DNA together forms nucleiosome, it helps in organisation of chromosome in eukaryotes.