Tiny creatures [teaching]
Sep. 22nd, 2021 12:48 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
rebeccmeisterI don't remember if I've specifically mentioned this here or not, but this fall I am teaching a lab section of our General Biology I course. The past three falls, I have taught one or two lecture sections, but have never had a chance to teach the lab. That made it difficult for me to understand how the lecture and lab should fit together. So - now I get to start remedying that.
One thing that I learned last spring is that it is extremely helpful for students if I make a short introductory video for each lab that I teach, where I can demonstrate the correct technique for doing something or using a certain piece of instrumentation. I think these videos wind up being WAY more engaging than lecture videos where a person is trying to teach concepts; lecture videos are much harder to get right.
Anyway, General Biology here is one of those courses where there are a whole bunch of different lecture sections and a whole bunch of lab sections. So the teaching experience is much more similar to my teaching experiences as a graduate student where we were put in charge of labs but had some organizational oversight from a lab coordinator. Whether they know it or not, students here are very lucky to have professors teaching labs rather than graduate students (no knock against the graduate students - it just takes time to get the experience that makes teaching more effective!).
A lab to teach students the basics of microscopy is standard fare for most General Biology courses. When I taught it in Arizona, I was always a little frustrated by how the lab would go, because we'd do a few things to cover the basics, and then some weeks later when we came back to use microscopes again to look at some actual things, the students would all have amnesia and we'd have to show them how to use the scopes all over again.
Students here are set up better for success. For one thing, instead of looking at the letter "e" from newsprint, we're looking at real cells right away. For another thing, every student has their own scope. And for a third thing, we just got brand-new compound microscopes this year. And for a fourth thing, we have our very own Scanning Electron Microscope in an instrumentation center here and the students get to operate it during this lab!
So anyway, here's what I put together for the students in terms of a short video on how to use a compound microscope, for your edutainment since I don't actually think my students are going to watch it, because reasons (already shared on other social media):
And here are some fun photos of the things the students got to prepare slides for, look at, and learn how to measure. Whoever came up with the idea to task students with measuring cells of different sizes was a genius, because this activity forces students to actually learn how to use the scopes, AND it gives them direct experience with looking at and thinking about cells of different sizes.
It's also fun to take photos through the microscope ocular lens. So here we go.
Onion skin: Take a slice of onion, snap it so it's only connected by a single layer of skin, then peel off that skin and stick it on a slide. Best with red onions:
Euglena! These guys move around pretty quickly, so as one student put it, it's kind of like watching animated wallpaper:
I took this photo through the ocular lens that has the ocular micrometer in it - the tiny ruler that gets used to measure sizes of things.
The euglena are blurry at a higher magnification because they move too fast for the camera.
Here's a Blepharisma, in between the numbers 10 and 11 on the ocular micrometer:
Do you see it now? Also a swimmer. So twee!
We also had some strained yogurt that contained both Lactobacillus (rod-shaped) and Streptococcus (spherical). This photo is at the highest-possible magnification with these scopes, 400x:
If you're having a hard time understanding this photo, know that students also had a hard time finding these microbes and measuring them, because they are so TINY, even at the highest magnification. There's also hardly any Lactobacillus in the image above. Very different to view them through a scope vs. just glancing at photographs.
For working the SEM, the students looked at fern spores, Drosophila, and Daphnia. To get them thinking about the advantages and disadvantages of different microscope types, we also set up compound microscopes where they could view the same specimens. I don't have any of the SEM images, but here are those three things under the compound scope:
The Daphnia are pretty darned cute, and were fun because they were very active, too.
One thing that I learned last spring is that it is extremely helpful for students if I make a short introductory video for each lab that I teach, where I can demonstrate the correct technique for doing something or using a certain piece of instrumentation. I think these videos wind up being WAY more engaging than lecture videos where a person is trying to teach concepts; lecture videos are much harder to get right.
Anyway, General Biology here is one of those courses where there are a whole bunch of different lecture sections and a whole bunch of lab sections. So the teaching experience is much more similar to my teaching experiences as a graduate student where we were put in charge of labs but had some organizational oversight from a lab coordinator. Whether they know it or not, students here are very lucky to have professors teaching labs rather than graduate students (no knock against the graduate students - it just takes time to get the experience that makes teaching more effective!).
A lab to teach students the basics of microscopy is standard fare for most General Biology courses. When I taught it in Arizona, I was always a little frustrated by how the lab would go, because we'd do a few things to cover the basics, and then some weeks later when we came back to use microscopes again to look at some actual things, the students would all have amnesia and we'd have to show them how to use the scopes all over again.
Students here are set up better for success. For one thing, instead of looking at the letter "e" from newsprint, we're looking at real cells right away. For another thing, every student has their own scope. And for a third thing, we just got brand-new compound microscopes this year. And for a fourth thing, we have our very own Scanning Electron Microscope in an instrumentation center here and the students get to operate it during this lab!
So anyway, here's what I put together for the students in terms of a short video on how to use a compound microscope, for your edutainment since I don't actually think my students are going to watch it, because reasons (already shared on other social media):
And here are some fun photos of the things the students got to prepare slides for, look at, and learn how to measure. Whoever came up with the idea to task students with measuring cells of different sizes was a genius, because this activity forces students to actually learn how to use the scopes, AND it gives them direct experience with looking at and thinking about cells of different sizes.
It's also fun to take photos through the microscope ocular lens. So here we go.
Onion skin: Take a slice of onion, snap it so it's only connected by a single layer of skin, then peel off that skin and stick it on a slide. Best with red onions:
Euglena! These guys move around pretty quickly, so as one student put it, it's kind of like watching animated wallpaper:
I took this photo through the ocular lens that has the ocular micrometer in it - the tiny ruler that gets used to measure sizes of things.
The euglena are blurry at a higher magnification because they move too fast for the camera.
Here's a Blepharisma, in between the numbers 10 and 11 on the ocular micrometer:
Do you see it now? Also a swimmer. So twee!
We also had some strained yogurt that contained both Lactobacillus (rod-shaped) and Streptococcus (spherical). This photo is at the highest-possible magnification with these scopes, 400x:
If you're having a hard time understanding this photo, know that students also had a hard time finding these microbes and measuring them, because they are so TINY, even at the highest magnification. There's also hardly any Lactobacillus in the image above. Very different to view them through a scope vs. just glancing at photographs.
For working the SEM, the students looked at fern spores, Drosophila, and Daphnia. To get them thinking about the advantages and disadvantages of different microscope types, we also set up compound microscopes where they could view the same specimens. I don't have any of the SEM images, but here are those three things under the compound scope:
The Daphnia are pretty darned cute, and were fun because they were very active, too.
no subject
Date: 2021-09-22 07:13 pm (UTC)the students would all have amnesia
For some reason, I have it in my head that you actually have to tell people or show people somethiing three times before they remember it. (A short quiz might count as showing. 😊)
no subject
Date: 2021-09-22 07:23 pm (UTC)You are right about the three times, but also, the way that Arizona lab was taught, I don't think it ever provided opportunities for students to play around with the scopes enough to really get the hang of them.
The brilliance of an instructional video is that someone can watch it as many times as they like, and I'll be just as patient every time. :^)
no subject
Date: 2021-09-22 07:49 pm (UTC)