Question

Choose the correct statement about DNA packaging from the following.

• A. The beads-on-string structure in chromatin is packaged to form chromatin fibers that are further coiled and condensed during metaphase.
• B. A typical nucleosome contains 300 bp of DNA helix.
• C. Histones are rich in the basic amino acid residues glycine and arginine, both of which carry a positive charge.
• D. In a typical nucleus, the region of chromatin which stains light is referred to as heterochromatin.

Answer 1

Answer: (A)

The beads-on-string structure in chromatin is packaged to form chromatin fibers that are further coiled and condensed at metaphase stage of cell division to form chromosomes. The packaging of chromatin at higher level requires an additional set of proteins that collectively are referred to as non-histone chromosomal (NHC) proteins.