step into my classroom: life science at ECA, quarter one

So far this year we have had several opportunities for student-driven inquiry and learning in life science, which makes me really happy. Here are just a few highlights of our first quarter together.

During our study on cells, we talked about cell membranes and the importance of permeability in allowing substances to enter and exit the cell. Usually I demonstrate osmosis with an egg that has had its shell removed, but that demo has gotten to be pretty boring and besides it's a waste of a perfectly good egg! Taking my cue from Pinterest, I set up a new version of the experiment using gummy bears. If you know me at all you know gummy bears are an integral part of my classroom!

So for our inquiry we tested the effect of regular water and salt water on gummy bears. Students hypothesized about whether the gummy bears would shrink, grow, or stay the same based on the passage of water in or out of the bear's membrane. Much to our dismay the bears dissolved within a few hours, we suspect due to the fact that we used warm water. A second round of samples was set up, this time using cold water. The outcome was quite startling - after just one day the gummy bears placed in the regular water had shown visible swelling, and the bears in the salt water had begun to shrivel up.

Salt water on the left, regular water on the right

We decided to leave the bears over the weekend and by the time we removed them from the water on Monday afternoon they had increased in size by more than 500%! The coloring had completely disappeared, but the bears maintained their shape despite their gargantuan size! The students had fun playing with the jiggly gummies, and a few tasted them. Not surprisingly, they weren't very flavorful. Check out this video to see just how big they actually grew (sorry, no sound and I'm not sure why...).

One major skill covered in life science is the ability to use a microscope properly, as well as the handling of slides, preparation of specimens, etc. It's always my absolute favorite lab in life science because the kids get to zoom in and see with their own eyes the complexity of life. Common phrases heard during this lab include, "WOW!" "Awesome!" "Coolest thing ever!" and the like.

This year students got bored with their celery leaves pretty quickly, and they took to the skies for an end to their boredom. You see, we've been plagued by a ridiculous amount of flies for a few weeks now. So the students caught/killed one of the pests, plucked off the wings, and prepared a wet mount so they could examine the details. I have never seen such awe and wonder as I did that day watching the kids bring their flies into focus! Some groups continued their investigation, looking at the legs and eyes of the fly as well. I have to admit, I too was amazed by the design evident in something as seemingly simple as a fly's wing. It's always good for me to see through the eyes of my students. Here are some shots from the lab, including one really cool image I got through the microscope using nothing more than the camera on my phone! What an amazing picture of our creator God!