Answer:
The degree of compaction of the 30nm (width) of chromatin fiber is 27 fold while this level of DNA packing represents only 0.27% of the total 10,000-fold condensed DNA.
Step-by-step explanation:
width: 30 nm
length: 50 nm
1 nucleotide (base pair) has a length of 0.34nm
Degree of Compaction
If per 50 nanometers length of double-stranded DNA you have 20 nucleosomes (200 bp/nucleosome), then the degree of condensation would be: 20 nucleosomes x 200 bp/nucleosome x 0.34 nm/bp = 1360 nm
1360nm/50nm= 27.2.
The degree of compaction of the 30nm (width) of chromatin fiber is 27 fold.
Fraction of 10,000 fold condensation.
There are 6 levels of compaction (or condensation) of the DNA:
level 1, in which there is no condensation at all,
level 2, in which there is a 3 fold condensation (beads on a string),
level 3, in which there is a 27 fold condensation (30-nm of chromatin packed nucleosomes)
level 4, in which there is a 700 fold condensation,
level 5 with a 1,000 fold condensation (a condensed section of a chromosome),
level 6 with a 10,000 (net condensation of a DNA molecule in a chromosome during mitosis).
The fraction that the 27 fold condensation represents out of the final 10,000-fold condensation is
27/10,000 = 0.0027 or in percentage would be (27x100)/10,000 = 0.27 %, which means that this level of DNA packing represents only 0.27% of the total 10,000-fold condensed DNA.