Unit 4 Wrap Up

Remnants of our photosynthesis lab

You know that feeling when everything hits the fan?  That's been my past couple weeks.

I thought Cellular Respiration and Photosynthesis went well.  My test results from last week said otherwise.  Looking back, Unit 4 was WAY too much material and way too diverse of material.  I was aware of this while I was teaching, but I didn't realize quite how significantly it impacted my students until the test.  Grades were still good, but class averages were lower than usual.

In my darling standard biology class, the 50:50 split was worse than ever.  Half the class had high As, two Cs, and the remaining students failed and failed badly.  For those students who failed, they temporarily lost their lab privileges and in lieu of lab completed an open notes re-test.  The strategy seemed to help, re-test grades were much improved, and I was able to work one on one with many of them while the other students were working on a dialysis tubing lab.  I realized two things working with the students individually:  1) just how overwhelming this unit was, and 2) the average sophomore in high school knows NOTHING about plants.  I mean nothing at all.  Multiple students said that my class was the first time that had EVER heard that plants make their own food.  I'm not sure I've ever encountered that before... but without any prior knowledge to help make connections, the process of "photosynthesis" was a billion times harder for them.  Who woulda thunk it.

In the meantime, we've started Unit 5 The Cell.  I've made some modifications due to time.  We did an intro to the microscope and looked at plant and cheek cells.  Then we did some diffusion/osmosis experiments, including perfume in air, food coloring in water, and glucose/starch in dialysis tubing.

Out of all my classes, only ONE group included "air" particles in their diagram.  Obviously this wasn't the group.

Dialysis tubing with glucose/starch solution placed in a beaker of DI water and Lugol's Iodine.  Fun fact- glucose didn't diffuse through the tubing as it should have this time around. I inadvertently reinforced a misconception in all my students' minds.

Not the strongest conclusion ever... 

We also set up a "rubber egg" osmosis lab instead of the potato lab included in the teacher notes.  Meh, I wasn't feeling the potato set up.

We have, count 'em, less than FIVE more weeks to get through:  transcription/translation/protein synthesis, enzymes, mitosis, meiosis, and all of genetics.  Ouch.  Let the panic attack begin.