Organisation of DNA

• each molecule is wound around the protein histone into chromosomes
• 16,569 base pairs in mitochondria used to establish maternal family ties
• 3.3 billion base pairs in genomic DNA
• mitochondrial DNA consists of a loop without histone proteins
• loop of DNA without histone proteins in chloroplasts
• prokaryotes have loops of DNA in the cytoplasm not wound in histone
• some viruses have a loop form of naked DNA