Question

The chromatin consist of a repeated pattern of bodies called as
A. Histones
B. Nucleosomes
C. Episomes
D. Chromonema

Answer 1

The DNA and RNA are made up of substance within the chromosome. It is called chromatin. It is also found in the nucleus of eukaryotic cells. The major function of chromatin is the packaging of long strands of DNA into a compact structure.

Complete answer: The chromatin is a fine thread-like structure seen in the nucleus which comprises the complex molecule called the DNA and proteins. The structure of chromatin can be best seen in the anaphase stage of the cell cycle as the DNA is highly coiled and is condensed in the form of chromatin. The chromatin is composed of a protein called histones around which the DNA strands are wound around. These coiling of DNA around histones form nucleosomes, which appear like beads on the string. Thus, the basic repeat on the chromatin structure is the nucleosome.
a) Episomes: It is the genetic material in bacteria that is able to replicate freely in the cytoplasm or can combine with the main genome.
b) Chromonema: It is the coiled mass of threads that are visible in the nucleus. It generally appears at the early prophase stage of the cell cycle.
Thus, the correct answer is option B.

Note: The histones along with the linker DNA help in making the structure of chromatin compact, so that it can accommodate inside the nucleus. The 20-60 bp of linker DNA form nucleosomes that appear as beads in the string. Nucleosomes form the backbone for the formation of a dense compact chromatin structure. It also helps in regulating the gene expression.