Sunday, February 5, 2017

A human life emerges from a single cell, a tiny sphere about 0.1 mm in diameter. That cell gives rise to hundreds of billions of cells during fetal development. At maturity, a human of   average size contains about 65 trillion (65,000,000,000,000) cells. With some exceptions, each of these 65 trillion cells contains a progeny replica of each of the  about 20,500  genes.