We spent the afternoon period on science. I’d given some individual microscopy lessons during the last immersion, where we looked at exciting protozoans moving around in pond water. This time they tried their hands at onion cells and staining with iodine, using a very nice and clear YouTube video posted below (kyliefansunited, 2008) as a reference.
The immersion oil had arrived in the mail earlier in the week so we got to try out the 100x oil lenses. We can now see structures inside the nucleus quite nicely.
Other things did not go so well. I’d written up, using the excellent recommendation of Anna Clarke, what I though was a neat exercise to look at the effect of osmosis on the cells of a waterplant, Egeria densa. The small group struggled with it, I think in large part because they were not quite prepared (had not done the background reading), and weren’t working very well together today. I’ll keep it on the schedule, but next time I’ll have to think hard on if it will be necessary to tweak the exercise.
