Our experiment with micro-organisms

As part of our theme we have been looking at Micro organisms. Micro-organisms are living feeding things that cannot be seen by the naked eye. They cause mould and decay. We performed an experiment on yeast and what it needs to grow. We had a choice of adding hot water or cold water and also sugar.We placed the mixture into a plastic bottle and then we put balloons over the top of the bottle.We watched them blow up and explode it was exciting.We discovered that the bottles that had no sugar didnt blow up and the bottles with cold water didn't blow up either. This was due to the yeast feeding on the sugar, and as a result it produces carbon dioxide. With no place to go but up, this gas slowly fills the balloon.