germs | Cullivoe Primary School

After undertaking the hand washing experiment last week and discussing the importance of why we wash our hands we decided to undertake another experiment as germs can be found everywhere, but some places have more germs than others. So this this experiment was used to see where germs are hidden.

This is what we did:

Miss Nicholson washed her hands, put gloves on and then cut a tottie into five equal pieces.
We took the first tottie piece and put it in a bag and sealed the bag. We used the marker to write on the bag and labelled this bag as our ‘control’. This is so that we can see what would happen to a tottie without anyone or anything touching it to be able to compare the others with it at the end of the experiment.
We then picked a surface, we decided on the classroom floor. Whilst wearing gloves we took a second piece of tottie and rubbed it on the floor. After this we placed the piece of tottie in a different bag, sealed it and labelled it with classroom floor.
We took the third tottie piece outside and lay it in a dirty puddle before placing it in a different bag and labelled it with outside after sealing the bag.
The fourth bit of tottie was passed around peoples bare hands but since we had washed our hands after the glitter experiment we thought we would rub the tottie on our arms as well as our hands. We then placed this tottie in a bag with a label ‘hands’
For the final bit of tottie we decided to rub this on the toilet! We placed this in a bag, sealed it and labelled toilet.
We then took all five bags and place them in a dark cupboard at room temperature in the classroom. We left them for a week.

After we put these away we wrote up what we did and our predictions as to what we thought would happen to the totties.

After the week had passed we pulled the bags out of the cupboard and look at the potato pieces. This is what we found:

The control tottie had a little white mould on it but hadn’t changed much.
The tottie that was rubbed on the classroom floor was brown with a little more white mould on it.
The tottie that was outside in a puddle was dirty, a little bendy and had more more mould starting around the edge. It had a bit of a skin on it so when you bent it the skin broke a little.
The tottie that was rubbed in the toilet went brown and had a skin on it. It was really quite bendy and when you bent it the skin started to crack and come off.
The tottie that everyone touched with their bare hands…had the biggest difference! It was squishy and had juice coming out of it. It smelt really bad too!!!

Once we looked at the totties we discussed the germs that are called mould or bacteria. The number of germs has grown so much that we didn’t need a microscope to see them. The mould that we could see on the control is important because it shows us how many germs already existed there. The other pieces started with this many germs but once they had touched other things the tottie picked up more germs.

After our discussion we wrote up our results and discussed whether our predictions were right, close or not what actually happened. The older pupils were really good at supporting the younger pupils.