Answer:
The two main types of DNA organization present in chromosomes are the extended DNI and the condensed DNI
Explanation:
In eukaryotes, the complete chromosome is composed of only one lineal and extremely long DNA molecule. DNA is intimately associated with two types of proteins: <u><em>histones</em></u>, which are structural proteins, and <em>non-histone</em> proteins that mediate different functions of DNA.
DNA associated with histones is called <u><em>chromatin</em></u>. Histones are responsible for packaging DNA molecule, and the fundamental unit of packaging is known as a <em><u>nucleosome</u></em>. As chromatin must be condensed, nucleosomes generate regular structures between themselves forming a <em><u>chromatinic fiber</u></em>, in which DNA is very condensed. A superior level of condensation is the structural <em><u>ringlet-shaped domain</u></em>. At this level, a chromatinic fiber is folded and a protein is responsible for keeping joined the two regions of DNA that form the ringlet. The next condensation level is the rolling of the ringlet-shaped domain composing the <u><em>chromosome</em></u>. The typical chromosome in the metaphase is formed by <u><em>two chromatids</em></u> joined by a centromere. Each chromatid is composed of a sequence of chromatin ringlets domains. In the interphase, <em>before cellular division</em>, chromatin is in a diffuse, lax, uncondensed state, known as extended DNA. When <em>cellular division</em> is about to happen, chromatin begins to condensate. At the beginning of the <em>prophase</em>, DNA is condensed in a well-defined chromosome formed by two sisters chromatids.
