Page 40 - The Microworld Miracle

Cell division
Released
7- Spore for- spores
mation and Cell wall
their release Non-reproducing
spore
Plasma mem-
Spor ka-
bu¤u 1- Filament brane
6- formation DNA
Completion Upper layer
of sheath
synthesis Nucleus
Spore sheath 2- Septum
formation

5- Sheath
synthesis
Non-reproducing
spore

Upper layer 3- The swallowing
of the first emergin
spore
4- Upper
layer forma-
tion

The bacterium protects its offspring, or sister cell, in order to
ensure the survival of its line, and sacrifices itself to that end.
This process, known as sporulation, is illustrated in the above
diagram.

single-celled living things possess to ensure their de-
scendants' survival. A bacterium that senses that the pre-
THE MICROWORLD MIRACLE ner. The main cell constituting the spore has no qualms
vailing conditions are not suitable for life immediately re-
alizes it is time to divide and acts in a self-sacrificial man-

about becoming a protein sheath. It cannot foresee the

survival of its line or know beforehand how to ensure
that survival. But can bacteria make such a decision?

38 How is the bacterium selected that will have to die in the