What is a microbe?

What is a microbe? How big are they? Are they all uper bugs or are they all friendly?

Please give me a short easy definition for chemosynthesis and photosynthesis! Thanks. 0_o

Is their any possibility or has their been any possibility of life in the solar system in the past, or any known places that ...

Do you think there is life on Europa? If so what type of life, bacteria, fish, human, intelligent life, Kardashev type 1, 2,...

This question just popped in to my mind. Who thinks that there is life on other planets not in the milkyway?!? I have wondere...

So this might seem like a stupid question, but I would like to know whether they two is completely separate or the same thing...

what do you think about evolution please give some evidence for and against it