Tag Archives: staying healthy

Tottie experiment

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.

We then started making posters to remember to wash our hands so that we can put these up around the school.

A scientist comes to visit

Today Meilo’s sister in law, Venus, came in to talk to us about the work that she does and a little about where she lives. Venus is a scientist that works for a pharmaceutical company. She lives in New Jersey in America. Her daughter Vicky came in with her to draw pictures to help us understand the work that she does. It was very interesting and Vicky drew some really good diagrams of the body and the cells within it which helped us a lot.

Venus talked of how the body is made up of lots of different cells and these are like building blocks that make our body. The white blood cells fight bacteria but some bacteria can try to fight back. Our immune system is amazing though and it can specifically identify the bacteria so it know to kill the bacteria straight away. Bacteria can get into our bodies through any cuts as they go into our blood stream. So remember to clean and cover any cuts to help you stop bacteria getting in and harming your body.

Venus went on to talk about cancer and how cancer cells are much bigger. Did you know that these are actually our own body cells that are out of control, they keep dividing and growing and do not function properly.

There is many ways to try and get rid of cancer. One way is to remove it through cutting it out. They take a biopsy, taking both the normal cells and the cancer cells to look at them under a microscope to look at the differences and compare them. They also compare them to look at the similarities to bacteria. However cancer cells can change so that they don’t respond to the drugs that should have helped get rid of them. Scientists use antibodies to tell what type of cell it is. They then crush the cells to look at their blueprint which helps them pinpoint how they are made up and they can then try to determine how to fight them.

Scientists are now trying a new approach to help fight cancer. They are using our own immune system to teach it to kill the cancer its self. The immune system gets tired and can’t fight these so the cancer shuts down the ‘good cells’ and stop them working. Scientists look at cancer cells and the changed cancer cells and compare this to normal cells. Therefore they want to try to revive the immune cells so they work again. They can create shapes to attract the good cells and the cancer cells closer together.

It is really important to keep your immune system healthy! Here are some ways that we knew on how to do so:

  • healthy diet
  • drink lots of water
  • get enough sleep (this is really important!)
  • and finally…LISTEN to your doctor! If he gives you medicine to take then you should do what he says as it will help you!