Midi-chlorian

see also: The force

Anakin: Master, sir, I heard Yoda talking about midi-chlorians. I’ve been wondering, what are midi-chlorians?

Qui-Gon Jinn: Midi-chlorians are a microscopic life form that resides within all living cells.

Anakin: They live inside me?

Qui-Gon Jinn: Inside your cells, yes. And we are symbionts with them. Anakin: Symbionts?

Qui-Gon Jinn: Life forms living together for mutual advantage. Without the midi-chlorians, life could not exist and we would have no knowledge of the Force. They continually speak to us telling us the will of the Force.

Qui-gon Jinn and Anakin, on midi-chlorians