This week we have been learning all about Bacteria. Bacteria, a type of prokaryotic cell, can come in an assortment of shapes:
As we are currently studying the plague we decided to concentrate primarily on the rod-shaped bacilli, of which Yersinia Pestis (the bacteria that causes the plague) is one:
Yersinia Pestis magnified x200
The first assignment was to learn all they could about a bacterium cell and express their knowledge in a way that would help them to remember.
To help A5 and B3, I read from the Magic Tree House Germ book we had used for the Fungi, and they watched a YouTube video which I hoped would help them to have a greater understanding of what bacteria was:
After the older children had done their research on their computers, they got to work on their bacterium cell. T12, as usual, made his cell in MineCraft. He is currently creating a home school world in Minecraft which will contain models or representations of all sorts of his learning.
He had already made a fungus, which I completely got and understood. The bacterium cell I struggled a bit to follow his vision. He explained it to me very patiently, obviously understanding not only his model but also the workings of a bacterium cell in general. And I thought I understood, I really did, but when I downloaded the photos I took of it, I found myself thinking ‘Eh?’ Any understanding I had has disappeared. I’m still going to post it, because the assignment was to represent a bacterium cell in a way that would help him (not me) understand the function of each of its organelles:
- Shows the actual bacterium cell, complete with flagellum at the rear (the green structure on the left)
- This is where I came unstuck, and even with the key (posted in the photos below) I couldn’t make head nor tail of it!
- Key to the colours in pictures 1 and 2
- More of the key
C11 asked if she could draw a super size bacterium cell and write inside the cell in speech bubbles what each organelle did as if each one was talking. I thought this was a brilliant idea and one she did really well; L11 took herself off into the kitchen and started boiling up pasta, her goal to make an edible model of a bacterium cell. Her model was probably the clearest, but to be honest as each child was talking me through their model I was impressed by how much they had learnt in such a short time. Their models made sense to them and really that was all that mattered:
- L11’s edible bacterium
- L11 explaining what each part was and their functions, using a computer model as a prompt
- C11’s fully drawn structure of an A3 size bacterium, along with many explanations as to functions and abilities.
- A close up. I really enjoyed the personifications of all the organelles!
After they had completed their assignment I popped on the following video. It had been this video which had inspired me to come up with a model for A5 and I to make together:
We used a smallish child’s test tube which came complete with lid, some clear hand soap (any see through thick liquid would have worked), some pipe cleaners, a stress ball, plasticine in two different colours, thin strip of ribbon and a pair of scissors:
The first thing we did was fill the test tube (capsule) with the colourless hand gel (Cytosol), adding the yellow play dough balls (Ribosome) and the orange play dough balls (Plasmids) as we went. We then slipped the pipe cleaner (DNA, no nuclear membrane) down the middle, topping up the gel right to the rim of the test tube, leaving no air at all inside. We replaced the lid:
Next we took the stress ball (containing the pilli) and slit it along its face to enable the insides to be seen after we had slipped it over our bacillus capsule:
I made a small nick at one end with some sharp scissors and prodded in the ribbon (Flagellum):
And here is our final model. Cool no?
We are currently growing bacteria to find out how accurate this report is, which states that most dish cloths have been found to harbour more bacteria than a toilet and to discover which is the dirtiest area in our kitchen. I may or may not share the results….
After we have the results back, we will then be testing different cleaning solutions to find out which is the most effective against the spread of bacteria. We also plan on testing the effectiveness of toothpaste and mouth washes when brushing our teeth and if we have time we will test what type of hand washing produces the best results. Our final bacteria project will involve testing whether or not yogurt contains bacteria and then to demonstrate how this bacteria can turn milk into yogurt.
