Recently in primary 6 we have been studying microorganisms as part of our focus in science and health and wellbeing. In addition to learning about the various roles played by microorganisms, on Friday we carried out an experiment which proved that they are alive!
To plastic bottles we added warm water, yeast (the microorganism), and sugar. We mixed the components together and then topped the bottle with an empty balloon. After a while, some of the ballons started to fill with (a tiny amount of) air, which was produced by the yeast feeding on the sugar. This production of gas indicates that the microorganisms are a living organism.