We wrapped up our study of invertebrates this week with a focus on the Arthropod Phyla. I opened class with a short lecture portion, again encouraging the kids to take notes on the chart I had created the previous week or directly into their notebook.
- hard exoskeleton which they molt several times as they grow
- bilateral symmetry
- jointed appendages (legs and antennae)
- largest animal phyla – more arthropods than any other animal
- insects – 3 pairs of legs
- arachnids (spiders & mites) – 4 pairs of legs
- crustaceans (crabs & lobsters) – 5 pairs of legs
- millipedes & centipedes.
I had stations set up around the room introducing the kids to the diversity of insects (each station focused on a characteristic of a specific insect order). Each station had a card (with printed instructions), a photographs, and at least one actual specimen to observe with a hand-lens. I have created a slide presentation that you can use to simulate these stations with your students. Though helpful and certainly of interest to the kids, the actual specimens are not required. You can download the presentation here: Insect Classification.
Upon concluding the first activity, I then introduced the inquiry portion of the lesson. I had purchased in advance several live arthropods – 3 Madagascar Hissing Cockroaches (Class Insects, Order Blattodea), Bumblebee Millipedes, and a dozen or so pill bugs (Class Malacostraca [Crustacea], Order Isopoda). The kids were divided into small groups and instructed to devise a simple experiment to test an experimental question. For example,
What food(s) do the cockroaches prefer?
What temperature do the pill bugs prefer?
Do pill bugs prefer light or dark?
Each group was allowed to utilize any number of the things I had on hand to set up their experiment – cardboard boxes, paper towels, ziplock baggies, aluminum foil, a variety of food (oatmeal, grapes, carrots, crackers, etc.) I was delighted to see how well the kids worked together in the limited time we had to complete the activity. Each group was able to quickly decide upon a question and devise a way to test their hypothesis. However, we did not have the time to carry out different trials (repeat the experiment) and regardless, the sample sizes were too small to make any conclusions. The activity provided me with a good understanding of what they understood about inquiry activities, however.