What did dogs teach humans about diabetes? – Duncan C. Ferguson | TED-Ed

What did dogs teach humans about diabetes? – Duncan C. Ferguson | TED-Ed.

I was directed to this website for an amazing collection of element videos, but I wanted to have a look around at their other lessons and then stumbled on to one about Dogs and Diabetes. The video is less than 4 minutes long, subtitled and really interesting for anyone looking at the history of diabetes, insulin or even animal testing. From Ancient Egyptians to Man’s Best Friend… What did dogs teach humans about diabetes? And did they benefit at all from it?

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Animation – Transport of Water and Sugar in Plants

Animation – Transport of Water and Sugar in Plants.

This is perfect for KS4, specifically unit B4e, an animation regarding the key processes of plant transport in xylem and phloem. As it is from saps, there is also a selection of downloadable notes including teacher notes and an A-level student revision guide, which might be suitable for GCSE, too.

Some of this goes perfectly with the “at home” science I’ve been finding recently!

Lammas Science – YouTube

Lammas Science – YouTube.

I’ve just been sent the link to this YouTube page and… Oh… My… God. I once spent an entire summer recording all of our VHS tapes onto the computer so that we had a digital copy. It took forever and although I didn’t actively watch them, I had to keep the sound on so I could catch the end of each episode. From the looks of this YouTube account, I needn’t have bothered!

If you look under Lammas Science playlists, you get collections of videos divided into different KS4 units (B2, C4, etc), there are Bitesize collections, other BBC show colelctions (Wonders of, for example) and broader topics (like forensics, pyrotechnics).

Easily an important site to bookmark, and view whenever needed. The fact that videos are labelled with relevant titles, especially linking them to specific KS4 units is what is most helpful!

STEM – Blackcurrant Osmosis

Who doesn’t love Ribena? And chips? Okay, maybe not really together as such. I found this experiment through Practical Biology a few years ago, but have only just got around to testing it myself and then putting it into a STEM session. The Practical Biology/Nuffield site have lots of different experiments you can browse through, each with teacher and separate student guidance. I simplified the Blackcurrant Osmosis one for the time and age of the students.

It really is very simple and easy to set up. Also, it’s very visual for students to look at. Here are some of our potato chips after 15-20 minutes in different Ribena concentrations –

Blackcurrant Potatoes

It’s quite obvious which one is 0% Blackcurrant and which is 100%. It’s pretty clear even for the other concentrations. That wouldn’t happen with plain old sugar water, would it?

We did this with a group or KS3 who knew nothing about osmosis, nothing about concentration and had never done a practical quite like this before, but in the hour session they all did pretty well. I think this would be perfectly suited for an hour length lesson especially with the right background knowledge. I would simplify it for a repeat STEM session though and cut all of the chips to perfect size so that step could be cut out completely. I am pretty amazed at how well the year 7s did with making the different concentrations and, from the results, all of the concentrations were made pretty accurately. There was only one group with anomalous results that made no sense!

0% - 80% Strength

It’s all actually quite simple really – make 6 concentrations of blackcurrant squash (from 0% to 100%) (oh, and whilst Ribena works very well, so does the blackcurrant cordial we tried), put a pre-weighed potato chip into each concentration and leave for 15-20 minutes.

Floating Chips

(Note how the chips float with increasing squash concentration. Can you explain that?)

Then, remove each chip, pat them dry and weigh each one again. Then calculate the percentage change in mass.

0% - 100% Chips

The 0% blackcurrant was the only chip to not lose mass as water moved into it from the greater concentration outside of the potato cells. All of the others had water leave the chip via osmosis (to varying extents) as the water concentration was greater within the chips compared to the sugary Ribena.

For younger students, if you leave the chips in long enough they might get enough out of the experiment from just seeing the purple coloured chips. Can they explain it? And then with age/knowledge move on to the theory behind osmosis and the graphing example Nuffield gives.

I’d also like to try their example of altering this experiment to show the rate of water movement. Perhaps that would be better for understanding the basics behind osmosis for younger students.