What is a bacteria endospore and how is it an advantage for the bacteria?

Answer 1

An endospore is a very thick-shelled structure formed inside a bacterial cell when the conditions are bad for the bacteria. The endospore can withstand the adverse conditions and develop back into the regular bacterial form when conditions are better.

Bad conditions for bacteria: not enough water, wrong temp, ...

Here are some pictures: http://www.altavista.com/image/results?itag=ody&q=endospore&kgs=1&kls=0

Answer 2

The endo spore is a bacterial cell that has dried out - moisture content way down. It makes it hard to kill and creates a dormant state for the bacteria to stay in until more favorable conditions exist for regular bacterial activity.