Australia's Science Forum

Does anyone do the photosynthesis prac where you cut out disks of ivy, degas and place in bicarb solution?

How long before hand can the leaf disks be prepared? I have 4 classes starting P1 Monday to prepare 15 groups of 40 each class! I am wanting to at least get a head start but I am assuming they need to be fresh. Any info to the contrary would be greatly appreciated.

Yes, they need to be ultra fresh....we do this and it works really well (not in the numbers you're talking, however!).
Maybe dragoon some helpers?
Cheers

This prac sounds interesting - would it be possible to get a copy of it please? Many thanks

It's essentially this:

https://docs.google.com/document/d/1f0V ... t?hl=en_US

but we don't use the soap and use old overhead projectors as the light source

I can not access this link. Is there another site to look at or a document someone could share/email me? Thanks

We do this prac every year, & yep I do go a bit insane sitting for ages punching discs!
Another Adelaide labbie once said that he punches them the day before, & puts them in distilled water in the fridge. In the morning they're all sunk & ready to use. It works quite well, & I just put the flask on the vacuum pump for a little while to sink the few that are still floating.
Our prac sheet is attached.

We just have one Year 11 Biology class doing this, and they punch the leaf holes out themselves. That might not be feasible depending on the age group and numbers, I suppose. We use spinach or silverbeet leaves.

Thanks so much guys - my daughter was looking for something for her biol investigation so she might give this a try. Have a great weekend

Milo wrote:We just have one Year 11 Biology class doing this, and they punch the leaf holes out themselves. That might not be feasible depending on the age group and numbers, I suppose. We use spinach or silverbeet leaves.

Usually they would but this is an prac test so time is limited and they want them pre cut. As it is I think I am going to have put them in distilled water and bicarb solution as I cut as 3 classes are spread over Monday and one on Tuesday. I also have prac tests for phy sci on the same day at the same time in different buildings so I can't be everywhere at once.

Hi! Has anyone tried using elodea leaves instead of spinach leaf discs for this prac? I was wondering if it would work as well, and save me time punching discs.