How many cells do you have?

  • The average eukaryotic cell is about 200 μm (200 x 10-6 m. = 2 x 10-4 m.) long (p.109).

  • You have about 10 trillion (10 x 1012 = 1 x 1013) cells (according to our book, Cain et. al., p. 106).

  • (1 x 1013) x (2 x 10-4 m.) = 2 x 109 m. = 2 x 106 km.

  • The earth's circumference is 40 million m. (40 x 106 m. = 4 x 107 m. = 4 x 104 km.

  • 2 x 106 km. / 4 x 104 km. = 50.

  • If all the cells in your body were lined up end-to-end, they can wrap around the earth 50 times.