Question

The chemical nature of chromatin is composed of
A) Nucleic acids
B) Nucleic acids and histone protein
C) Nucleic acids, histone and non-histone proteins
D) Nucleic acid and non-histone proteins

Answer 1

Hint:Chromatin is a fibrous heredity material formed together by DNA and histone protein complex and some non-histone proteins are present. In eukaryotes most of the DNA is concentrated as chromatin in the nucleus.

Complete answer:
The chromatin is formed of DNA, RNA, and proteins.Composition of DNA is 30 – 40%, of RNA is 1 to 10% and of proteins is 50 to 60%. These elements range in exclusive organisms or even withinside the exclusive tissues of the identical species. What happens is the DNA wraps around histone protein; this structure is known as nucleosome. In addition, they look like beads on string-like structures.Therefore, number one content material of chromatin are histone proteins. Histones are small, positive charged proteins. Talking approximately the non- histone proteins in chromatin, the proteins which stay after the histones are categorized as non-histone proteins. Scaffold proteins, DNA polymerase, Heterochromatin Protein 1 and Polycomb are not unusual place examples of non-histone proteins.
Hence, we conclude chromatin alone cannot be formed of just nucleic acid, because DNA needs a protein structure to wrap around.Therefore, choice A is wrong. Option B is just talking about nucleic acid and histone proteins but not of non-histone proteins. As discussed, non histone proteins are very important for processing of DNA. Hence, it is wrong and finally, option (D) only talks about nucleic acids and non-histone proteins.

Hence the correct answer is option ‘C’.

Note:Without the structure of chromatin DNA, wrapping will not be possible. DNA gets the first level of compaction by wrapping around histone protein. About 2 meter of DNA is assembled into a small nucleus.