"Biology is the only science where division means the same thing as multiplication." - Anon.

Supplementary videos

Evolution of human chromosome #2: why do humans have 46 chromosomes, other great apes have 48?
DNA packaging: histones and nucleosomes (HHMI)
Cancer formation: abnormal cell division (HHMI)

Extra credit readings

• Proto-Oncogenes and Normal Cell Growth National Cancer Institute 09/01/06
• Brain cell regeneration sniffed out in adult humans New Scientist 2/15/07
• Ghost heart has a tiny beat Nature News 1/13/08

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