Biology Reference
In-Depth Information
DNA double helix
2 nm
Beads-on-a-strong
11 nm
30 nm-Chromatin
30 nm
Extended chromosome
300 nm
Condensed section of
metaphase chromosome
700 nm
Entire chromosome
1400 nm
Fig. 2.9
The step-wise packaging of a single-strand DNA double helices into a chromosome in
the metaphase. The “chunking” of the single-strand DNA duplexes into chromosomes facilitates
DNA replication and sorting during cell division (Downloaded from
http://library.thinkquest.org/
C004535/media/chromosome_packing.gif
, May 2009)
