Potometers?

Hello. I hope that you have all had a nice weekend.

I am just doing a piece of homework on potometers. Our teacher has given it to us, without us having actually studied plants yet!

I think I get the overall principal, but I get really stuck on the 'precautions questions.'

There is a question, which asks:

'Stat three precautions which must be taken when setting up this apparatus.'

I really do not know what to write.

Any help would be GREATLY appreciated.

Thank you very much,

Amrou

Reply 1

Lou_

1. The stem must be cut under water and the end of the the stem, rubber tubing and capillary tubing must all be connected under water - this prevents air entering the xylem and forming air locks.

2. Tightly fitting rubber tubing must be used - prevents leakage of water and ensures system is air-tight.

3. Time must be allowed for plant to equilibrate between different environmental conditions - ensures the rate of movement of the bubble is due to the factor being investigated and not the previous one.

And of course there's the usual; keep all factors equal (apart from the one being investigated) and repeat the experiment for each factor/condition so the results are more reliable.

Hope that helped!