NEET 2007 Biology question

The length of DNA molecule greatly exceeds the dimensions of the nucleus in eukaryotic cells. How is this DNA accommodated?

(1)Through elimination of repetitive DNA.
(2)Deletion of non-essential genes.
(3)Super-coiling in nucleosomes.Correct
(4)DNAse digestion.

Answer: (3)

Solution

In eukaryotes, negatively charged DNA is wrapped (about 1.75 turns, 200 bp per nucleosome) around a core of eight positively charged histone molecules (an octamer of H2A, H2B, H3, H4, two each), forming the "beads-on-string" structure of chromatin; this is further coiled

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Question ID VK-089820