Hi everyone, so today I taught a lesson on the immune system and wanted to share it with you all because it had a lot of engaging pieces that might work well for all of us in the future. Because I worked with some chemicals today I had my students wear goggles and gloves as they would if they were doing a regents level lab. Also, because of the size constraints of my room I ask that my students stay seated for class, which did limit one activity significantly.
My focus question for the day was “How does my body protect itself from what I can’t see?” It was interesting for the students and they really did gasp the main idea in the end, using connections from most of my activities.
I started with a bridge that asked how the students thought germs were spread and how quickly they could spread. This brought up a lively discussion in all three classes of the different types of germ transmission between people.
Following my short bridge I did a model of a cold spreading, like Jill did for STARS. Unfortunately because of the size of my room all my students stayed in their seats for the first two classes, and then in the third I modified the model to be entirely a demo that I manipulated with the help of my CT. For my first two classes students were instructed to share a part of their liquid with four other people and to record their names. In the last class my CT and I mixed the cups while a timer counted down one minute. After this I shared that we started with two cups being infected with a cold and this indicator (phenolphthalein) would indicate if someone was sick but it turning the liquid pink in each person’s cup. Students were asked to take about a minute to make a prediction and then I went around adding a drop of indicator to each student’s cup. I asked that infected students raise their hand to keep track of who got sick. This got them very engaged as they were all hoping that they hadn’t contracted the cold. In the end I averaged about 25 out of 30 infected cups, which was what I was hoping for.
I ended up making major modifications to this model after further talking through the safety considerations with some teachers in the building and considering the typical behavior of my last class. My first class handled the activity very well, which I can’t say surprised me because they are my best class. However, my second class is my most challenging, and in hindsight I think it would have been best if I had cut this demo out for them, they were very off task and distracted and it led to a small spill at one table. Because of all this I decided to have the class observe me while I did a shortened version of the demo at an open table. This still got the point across to everyone but was less exciting for them, especially when I was walking around with the phenolphthalein.
I was torn about this part of my lesson because I was really excited to do this model with my students. However, because of the chemicals involved (bleach) I got advice telling me to avoid it all together and to take very serious, strict safety precautions. Done over I’d like to try to model with a more safe base (or acid) and was wondering if anyone had some ideas. Obviously I could change indicators to account for using an acid, like white vinegar, but it hadn’t crossed my mind until I debriefed with Jo Ann that that was an option. Also, there is something cool to be said for the hot pink that the phenolphthalein turns in a basic solution.
Following this demo/model, two of the classes this segued nicely into my showing on “The Sneeze” because students identified sneezing without covering your mouth as a way germs spread; my third class required a bit more facilitation from me to make the jump to the video. The link for this video, if you haven’t seen it is below.
Then we spent a majority of the remaining class in reading stations with short blurbs about specific pieces of the immune system. This section worked well for me because I gave two of my three classes two minutes to silently read and then three minutes to answer the corresponding questions. For my third class I read the blurbs to them as a class because of some of my students’ lower reading levels.
I had an additional YouTube video that I found that appears student made that put a nice review on the four stations together. Unfortunately we only got to watch this video in one class because of time constraints but in the one class it made a world of difference in tying all the major concepts of the lesson together. Below is the link to that video.
We followed this video up with summary and closure, as we always do at my placement. The summary asked students to answer the day’s focus question and the closure asked students “If a vaccine allows your body to produce antibodies against a specific germ, why do you think we need to get a new flu shot each year?” This question worked well and got a variety of responses, including some variation of the right response; that is, that the flu “germ” changes slightly each year and so the antibodies aren’t as effective between flu season.
I attached my 4.9 Immune System Workshop, 4.9 Immune System Readings and 4.9 Immune System HW materials below for this lesson. It was done in a 70 minute class period but could also be broken into two pieces if need be. Ideally, to not be rushed, I think I could have used an extra ten minutes or so but given the hurdles thrown at me it went better than I expected in two of my three classes. I’m open to any suggestions or comments, as I’m sure you all have ideas that could improve on this work.