We’ve just spent a couple of weeks learning about Fungi. We’re not talking macro Fungi (mushrooms and the like) but Micro-fungi. Micro fungi are eukaryotic organisms which have an absence of the large fruiting body of the mushrooms and the like. Fungi such as mould, mildew, yeast and even rust. Both macro and micro fungus are vital for the survival of the world as we know it because they are decomposers, that is they break down organic matter.
The majority of micro fungi consist microscopic threads, called hyphae, often extending through material in which it grows. The mycelia produce thousands of tiny spores that are carried by the air, spreading the fungus. Yeast is the oddity, being unicellular and reproducing by simple mitosis and sometimes budding. We will be investigating the properties of yeast this week.
I had collected so many photos of the things we did that I decided to put them into a collage to reduce the size of the post:
Bearing in mind this is a project for all my children spanning from the 3-year-old up to the twelve-year-old, I needed to choose the resources carefully, making sure there would be enough my younger two could understand as well as ensuring the older ones were sufficiently stretched.
The magic school bus, funnily enough, was perfect for all five children, with the older children loving it as much as the younger ones. I also invested in the experimental set which went with the book. Whilst I could easily have found the contents in and around my home, it made it much easier for me to have everything laid out, as well as a useful instruction booklet.
- I read as much of the Magic school bus Germ book which pertained to moulds and then asked the children to do a quick skit demonstrating their learning so far. A fun way of assessing, the children really enjoyed doing it, with even A5 taking part as a strand of bread mould.
- Knowing we would be looking into fungi and therefore moulds, I allowed a chunk of bread to turn completely mouldy, almost all the way through. Literally, I left it in a cupboard for weeks.
- T12 is making a slide from a small portion of mould
- They each took it in turns to look at it through a magnifying glass
- Afterwards we placed it under our tv microscope which allowed us to get a (somewhat) clearer idea of the strand like property of fungi
- It is not a very clear photo but this is the fungi up on the screen
- Then each child looked at their own home-made slide for an ever clearer view.
- A5 really enjoyed this part. Afterwards they went away and researched how fungi looked and drew and labelled a simple diagram.
- L11 is demonstrating just how far the fungi had grown into the bread. In fact only a small amount of bread like substance existed deep in the middle, leading them to conclude that the mould used the bread as food
- All the children once again looked at the bread under a magnifying glass, now it had been sliced in two
- T12 is demonstrating the presence of spores by blowing gently on the bread
- A close up model of the Mucor fungus which was on our bread.
Once we had finished exploring the mould I had grown on the bread, I asked the older ones to come up with a representation of the Mucor we had studied including all the properties we had discovered so far. L11 had the idea to make hers from celery, peanut butter, using icing sugar for the spores. She was away at her art lesson when we did this and so although planned it very well, never got the opportunity to make it.
- C11 made hers from a plastic tube (sporangiospores hyphae protruding up and containing a sporangium), play dough (stolen, root hyphae and the sporangium ) and used flour as the spores
- Here she demonstrate the spreading of the spores by blowing gently
- T12 used Mine craft, of course, and built a mucor fungus with spores attached
- And a mucor fungus whose spores are airborne.
We carried out an investigation into optimum conditions for growth for a Mucor fungi. A5 and I prepared the control test tube, whilst the older children prepared three different experimental test tubes.
- A small piece of bread was placed inside the test tube
- Using a pipette warm water was added to the bread
- The bread was moved as far down the test tube as possible
- The test tube was labelled and placed in a warm dark cupboard (my larder)
This was repeated adding vinegar to one test tube, sugar solution to another and storing them both in the same warm dark larder as the control. T’s was the exact same as the control, only he placed his in the fridge (ie a cold dark place). The test tubes were checked daily, and moistened if necessary. Here are the results after one week:
We wrote out the results and a possible conclusion that might be reached:
- Our final conclusions were that the optimal conditions for mould growth on a piece of bread included warmth, energy in the form of sugar (sugar is a simple carbohydrate and therefore provided an easily accessible form of food unlike the more complex bread carbohydrate) and a slightly acidic pH. We rather wish we had tested the pH of the solution to give us more definitive results and would definitely do that if we were to repeat the experiment.
- I had to laugh when, having learnt about the fungi’s need for damp conditions, I caught T12 blow drying his feet, determined he would not get athletes’ foot! He cracks me up!
I have a couple more posts to finish up with fungi and then we will be moving onto bacteria, and linking it handily to the plague.