Population Growth Curves with Bubbles

This was another mini lab from the collection of labs from Dr. Close that I blogged about here. In this lab students were recreating the 3 different population growth curves by caring or not caring for a population of bubbles.

For the growth curve of k selected species who care for their young to maturity, students blow a bubble and do everything in their power to not let the bubble pop. This included blowing on the bubble and fanning it away from obstacles. This section certainly takes the longest because the bubbles last the longest. I started getting nervous that we wouldn't finish within out 80 minute time frame while students worked on this population, but fortunately, the other two population types go more quickly. Personally, I found this the most hysterical section of the lab, and I think students would agree. (Although none of my pictures quite captured how funny they looked chasing their bubbles around.)

In the next population, students blew a bubble, but could not help it along. This was a hard transition after protecting the first 50 bubbles so carefully.

In the final population, not only could students not help the bubbles, but for them to survive past birth, the bubble had to cross over a meter stick that was one meter in front of the bubble blower. These results mimic the r selected species, often where parents lay many eggs with no parental involvement past that.

After data was collected, students graphed their data on semi-log paper to see how well it matched to the graphs in their textbook.  I reformatted the lab into this document. For the semi log paper, I like the paper from here and choose the 2 decades paper.

This was a great lab to get students outside and moving around a lot. The lab also gave them a real experience to relate back to the graph they needed to understand.

Cell Membranes and Bubbles

I was happily reading through the Facebook feed of the AP Biology teacher group and saw a post from a teacher who had just done a bubble lab to teach properties of cell membranes. It looked like fun and I was about to embark on cell membranes. The lab is from Jeremy Conn of Clear Biology.  You can download the lab from his site here. I just used his resource without any editing--which is handy since I'm having a hard time keeping up with everything to do. I made some bubble solution on a Thursday, and we did the lab this past Monday.

I think sometimes I forget that even though I teach Seniors, they are still kids.  (Actually, we should all be kids at heart.) The students loved this lab and had so much fun playing with bubbles.  And in the end I felt like they significantly improved their understanding of cell membranes and the fluid mosaic model.

As they progressed through the activities, they got more excited. My favorite was the loop of thread that opened to a circle and then could move around the bubble frame like a transmembrane protein.

As they were cleaning up, I heard conversations about how they should do this bubble lab with their fourth grade buddies. (One advantage of being in a K-12 school.) Love it!