Chapter 14 : Immortality
A molecular biologist named James Watson in 1972 discovered that polymerases does not start copying DNA at the tip of the chromosome but they instead start coding part way into the DNA, so when the DNA is replicated, little bit of the telomere is left out. Telomerase is responsible for increasing the continuous division of cells. This explains why brain cells do not divide in order to save the vital genes they have. In Malignant cancer, cells switch the gene on after it has bee switched off by most cells in development. Ridley proposes a hypothesis that aging maybe be caused by evolution.
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