Question

Which statement is/are correct?
(i) Nucleosome contains basic protein.
(ii) Tightly packed DNA of chromatin is called heterochromatin.
(iii) Loosely packed DNA of chromatin is called euchromatin.
(iv) H2A, H2B are linker proteins.
(v) DNA is basic in nature.

(A) (i), (ii) and (iii)
(B) (i) and (ii)
(C) (i), (ii), (iii), (iv) and (v)
(D) (iv) and (v)

Answer 1

Hint: In eukaryotic cells, chromatin, a mix of DNA and proteins, makes up the chromosomes. Nuclear DNA does not exist as free linear strands; rather, it is highly compressed and wrapped around nuclear proteins to fit inside the nucleus.

Complete Step by Step Answer:
The long, thin fibers of chromatin. Inside the nucleus, they can be found as uncoiled formations. The chromosomes are tightly wound, hefty, and ribbon-like. When cells divide, these coiled structures are clearly visible. While chromatids are a portion of the chromosome that are connected to it via a centromere, chromatin is the indistinguishable mass of DNA molecules. Each DNA molecule that is attached to a histone protein is referred to as a chromosome, and this combination is known as chromatin. However, chromatin also regulates how the genome is read out from cell to cell and compacts the genome into the nucleus.

Heterochromatin is the region of the chromosome that is darkly stained when stained by a specific dye and is relatively compressed in size. Euchromatin is referred to be the region of the chromosome that is highly concentrated in genes and actively takes part in transcription. Less DNA is weakly compacted with the histone proteins in euchromatin. The histone proteins and more DNA are closely packed together in heterochromatin. Both prokaryotes and eukaryotes include euchromatin. There are only eukaryotes that include heterochromatin. A nucleosome is a part of DNA that is encircled by a protein core. DNA can be compressed and packed as a small volume inside the nucleus by making a combination with proteins that is known as chromatin. The structure of the expanded chromatin resembles beads on a string when examined under a microscope.

So, option (A) is correct.




Note:To create chromosomes, chromatin fibers are coiling and condensing. Numerous cellular functions, including DNA replication, transcription, DNA repair, genetic recombination, and cell division, are made possible by chromatin.