When it came time to tackle the nervous system, I decided we needed to be as hands-on as possible, working with models to help students understand what was going on in this complex system. I chose three activities for us to do. We did Pom-Pom Potential from http://teach.genetics.utah.edu/, then we did the Nerve Cell Communication activity from the Life Science Learning Center of the University of Rochester. (It's easy to request the link to be able to access their library of activities.) We finished up with a fun reflexes and reactions lab.
Doing the activities in this order brought us from micro to macro, but I think next year I'll reverse it and go macro to micro so students can go from what they can identify with (reflexes and nerve cell endings) to the more abstract of action potentials.
We had some good discussions about the membrane potential graph of a nerve impulse that was in the question sheet I made to go with Pom-Pom Potential. I would have liked to spend more time talking about the "macro" part of the nervous system of the nerve impulses traveling through the body and the benefits of reflex arcs. Hopefully each year I will tweak this to be better than the year before.
PS-One of my students was "babysitting" for a Junior health student during this activity--thus the doll in the corner of the pom-pom picture.
At the end of the school year last year, one of my students sent me the video of the Japanese students who hatched a chicken in a cup with plastic wrap and no shell. It looked fascinating and used readily available materials. I decided that we'd give it a try this year when we got into embryonic development.
I did some research and found a couple of helpful resources, one from the Cooperative Extension of the University of Connecticut and one from a text by Cynthia J. Fisher. We did a slight modification of the procedures to compensate for using an oven. It's really a drying oven that the Chemistry and previous AP Bio teacher figured out where to turn the knob to keep it at 37ish degrees Celsius for the bacteria labs we do. I pre-heated it on Monday so it was at 38 degrees Tuesday morning.
Note the duct tape holding it shut since we have it a little over-full.
There are several school families who keep chickens. A couple of them have roosters and were more than willing to provide us with fertilized eggs. This past Tuesday, we put the eggs in our "incubator". We added a few more to the incubator on Wednesday--long story, involving an extended school bus ride. =)
After incubating for two and a half days, we cracked the eggs during our Thursday afternoon lab. The yolk of the first egg broke in the process, then the next was rotten. (We had been warned about that potential because of finding some rotten eggs by the "brooding" chickens.) One more broken yolk, and then we had success. I think it helped to have to repeat the process since students got more comfortable with it as we went. In the end we cracked open a couple of extras and took two videos of hearts beating that we could see. We put them into their "cup homes" for the duration of their development.
To make the homes for the chicks, we used Styrofoam coffee cups, poked a pencil hole in opposite sides of the cup, poured water into the cups up to the pencil holes to provide extra humidity, placed cheap plastic wrap (in hopes the cheap stuff would be more "breathable") over the cup and pushed it down to form a sling, held it in place with a rubber band, and covered it with the bottom of a petri dish. Eight cups is a tight fit in our little oven, so not all of the petri dishes set well, but so far it appears to work OK.
Today, we checked our chicks-in-a-cup and were amazed by the embryonic development occurring in just under 24 hours! If I had to guess, students would say it was one of their favorite labs. And we're hoping it will continue for at least a week, maybe more. The students are voting for all 21 days of course. When we finish, for their lab reports, students will put together a movie of the process. I've included a video of what we've done so far.
The last set of guided reading questions has been updated and is ready to go. The end of the year is in sight. I'm excited, since this year we'll actually finish the AP Bio curriculum by the exam. This means we get to do a fun (in a morbid way) Ebola unit for the last three weeks of the year. Anyway, for the human unit we focus on the nervous, endocrine, and immune systems and embryonic development. I'm going to try the Pom-Pom Potential activity from Learn Genetics Utah and possibly Jumpin The Gap. Then we'll look at the Nerve Cell Communication activity from the Life Sciences Learning Center of the University of Rochester. We also do a fun lab looking at circulation in goldfish tails and the effect of epinephrine on the circulation. Still looking for a good immune system lab or activity.
