1. The length of DNA in one chromosome
The packaging of DNA in eukaryotic chromosomes or how you change this...
The length of DNA in one chromosome
4 cm
into this...
Too small to show the real size, but you could fit 10,000 along the length of a fingernail!
0.2-2 µm

2. Link to 3D animation of the packaging of DNA into chromosomes

3. Level 1: Nucleosomes or ‘beads on a string’
Linker DNA
Histone proteins form a complex

4. Level 2: Chromatin fibre
Nucleosomes coil and stack

5. Level 3: Looped fibres
Chromatin fibre loops along the protein scaffold
Protein scaffold

6. Level 4: More folds to make the most compacted chromosome
Looped chromatin fibre folds
The most condensed form of DNA packaging during metaphase. Replication has just occurred so the image shows two chromatids
0.2-2 µm