Eukaryotic Chromosome Structure

Packing Ratio of  Chromosome Structure

Packing ratio - the length of DNA divided by the length into which it is packaged

• Shortest human chromosome = 4.6 x 10⁷ bp of DNA (about 10 times the genome size of  E. coli).
• Equivalent to 14,000 µm of extended DNA.
• Most condensed state (during mitosis) = the chromosome is about 2 µm long.
• Packing ratio of 7000 (14,000/2)