bio lab -- microcosms lab in the Illustrated Guide

[Kate in Arabia]

We are covering biology this school year with Miller-Levine, using the Illustrated Guide as a supplement for biology labs. I have been picking and choosing labs to correlate with our chapters, not completing the entire book.

 

So now we're looking at microcosms and looking at the Illustrated Guide there's quite an experiment there with collecting pond water to create microcosms (section II). I do not have a science background, so please forgive any ridiculous questions.

 

#1 I live in a desert, so ponds are not common. With other experiments in the book we have been successful in using water that had been spilled on the side of the road and sat for some time (successful in that the water samples contained lots of microscopic critters to observe). However, this experiment appears to require more -- sediment, aquatic plants, etc. -- which we did not get in our water source (for the experiment requiring aquatic plants I got some from a pet store). The larger water source nearby is the ocean/mangroves, but I'm not sure what effect salt water would have -- . Will we be able to do this experiment?

 

#2 This looks to be more involved time and work-wise. If you have done this experiment before, was it worth that effort (sorry if that comes across wrong)?

 

#3 If we can't do this experiment, do you have any suggestions for a substitute? We have done a few paper labs recently, I'd like to get back to a more "hands-on" lab this time, if you know what I mean.

 

Thanks in advance for any advice.

[lewelma]

I don't have the Illustrated Guide, but if you tell me the details, I can help you rework this experiment for your conditions.

 

Ruth in NZ

[Kate in Arabia]

Thanks for your response, Ruth. The experiment starts by having you create four individual Winogradsky column microcosms with sediment, pond/stream water and any anchored or floating flora; you then add different things to three of them and observe regularly for over a month. These microcosms are then used in further labs within the same general topic.

 

I'm starting to think that this is too much for a non-sciency student. I was hoping someone here had done this experiment before and could comment -- or offer an alternative that wouldn't be quite so much.

 

..off to do some more searching. Thanks again for your comment.

[lewelma]

I love that all the North Americans are asleep and you and I are on opposite sides of the world and are awake! Good morning to you and good night to me.

 

I am happy to think about your problem if you want, but if you are going to scrap it, I won't bother.

 

Ruth in NZ

[Kate in Arabia]

Yes -- it's about 12.30 pm here, time for our lunch break! ;)

 

I'm vacillating, but don't want you to go to any trouble about it. I had thought the lab guide was a popular one here (at least, I thought I had seen it recommended with some frequency), so hoped there would be more chatter about it. Oh well.

 

Hope you're having a nice evening! :)

[Guest dmoon]

We did the microcosms lab earlier this year. I thought it was a worthwhile lab, and my kids found the results interesting. We did use pond water, though. A quick google search of 'winogradsky column salt water' give links to several sites that say you can use salty marsh water for the experiment.

[Kate in Arabia]

Thanks!