Date of publication: 2017-08-25 23:00
Heron Island is on the southern end of the Great Barrier Reef, Queensland, Australia. It seems likely that if turtle weed growth is determined at selected points along the reef flat on Heron Island then greatest growth would occur around largest clam due to the larger amount of nitrogenous wastes.
However, another teacher warned: We used to do osmosis/diffusion in the past but I learnt very quickly that unless you own some pretty powerful optical technology it may become an indirect evidence gathering exercise. Yes, you could with an egg after you dunk it in various salt solutions or distilled water. Also you could do something similar with various vegetable matter but the students won’t be actually observing the membrane in action so here you need to make a judgement call on the value of the exercise for the students. My past students found the exercise quite 'nebulous' and lacking 'tangible' outcomes.
The photos below provide a stimulus for those considering an EEI of this type. Some interesting background on feed requirements is provided by the Chicken Meat Federation of Australia.
The students did a study of the local weeds and noted lantana was very prevalent. They were then prompted by me to ask why and this led them to the reported allopathic chemicals in lantana.
Algae can also nearly double in quantity overnight, if the conditions are perfect (see EEI suggestion below). To achieve perfect growing conditions, producers must ensure that algae do not get too much direct sunlight, which can kill them, and that the growing environment is moist, has a constant warm temperature and has clean water with balanced salinity and the optimum pH. A good (but difficult) EEI would to make ethanol by the fermentation of algae as it can be done at home or in the lab.
Are there health implications of consuming large quantities of full cream milk? Should low fat milk be accessible in school tuckshops? Should flavoured milks be made with low fat milk? Does the addition of certain minerals affect the digestion rate of milk, such as PhysiCAL?
Be prepared for a long wait if you haven't done this before: Moreton Bay College took 7 years to get approval for their mice and chicken behavioural experiments (see below). A good starting point for more information for Queensland teachers is the Animals in Education website. Click here for an extract from the Biology syllabus regarding animal experimentation. Different precautions are necessary when students themselves are the subjects of experimentation (eg in homeostasis experiments). There is a CAUTION in the homeostasis section later on about this.
Every year our Year 9 students conduct an EEI into the effects of exercise on their body. They come up with a method which involves the type of exercise and the method for data collection. They make a choice to collect data on body temperature, heart rate, breathing rate, skin temperature, sweating rate (this is a little subjective). This is great for the homeostasis unit.
Alcohol is produced but its concentration is likely to be under 6%. Also, most fermented soft drinks are acidified to inhibit bacterial growth. Does this also inhibit the yeast? You could investigate the effect of pH on the rate of fermentation using lemon juice or better - citric acid. The juice of 6 lemon contains about 67 g citic acid. Be warned - you should not be drinking the ginger beer unless you have approval from your teacher (and this is unlikely). Drinking stuff made in a laboratory with no hygiene controls is DEFINITELY NOT PERMITTED.
Some plants have contractile roots that pull the bulb down into the soil. Oxalis (sour sob) does this, but the published work is on American species and it would be of interest to know how the local weed species ( Oxalis pes caprae ) behaves before designing eradication programmes. This suggests a possible EEI. Are you going to use bulbs of one particular size or compare burial rate/final depth of bulbs of different size classes? How does the final burial depth and switch over from vertical to horizontal contractile roots compare with depth of bulbs in the field? Click Project 9-7 for Prof. Jennifer McComb's resource sheet.
This should be considered a good starting point. There is room for some good quantitative (numerical) testing. I would suggest that a number of dilutions of the alleopathic solution be made to see if there is a correlation between concentration and percent germination. You could also ask what is the minimum concentration that will show an alleopathic effect? I know it will be hard to establish a starting concnetration but it could be expressed as g/mL such that if 5 grams of lantana leaves were macerated with 65 mL water the concentration would be /mL (or 55 g/L). Then you could do serial dilutions of this solution. Perhaps you could centrifuge the macerate, or filter it, so that you have a clear solution to start with. I wish I was doing it.