Question

How many nucleosomes are present in DNA of a human cell?

• A. $6.6\times 10^{9}$
• B. $3.3\times 10^{9}$
• C. $6.6\times 10^{7}$
• D. $3.3\times 10^{7}$

Answer 1

Answer: (D)

In a human cell, the length of DNA molecule is about $2.2 \, meter$ , in which about $6.6\times 10^{9}$ base pairs are present. This DNA is present along with histone protein in the form of 'Beads on string', which is called as a nucleosome. Each nucleosome carries 200 base pairs. So number of nucleosomes $=6.6\times 10^{9} / 200=3.3\times 10^{7}$ .