Saturday, October 10, 2020

Online and in-person lab design exercise using yeast.

Because my AP Biology classes this year are a hybrid model in which students can move back and forth from remote to in-person instruction based on their circumstances, I needed to design labs that were portable and could be completed in the home lab (kitchen). In order to teach experimental design, I developed a mini-unit using yeast (Saccharomyces cerevisiae).  Much of the work can be done asynchronously.

The introduction to the module sets the stage.

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Figure 1. Tyson on Curiosity



Science is about asking questions of the world.  It is how we get a clue.  Although there are many ways to “do science” including observational studies and case studies, the hypothetico-deductive method is the most well known and is often referred to as “The Scientific Method”.  In reality, science is never done in the step-by-step method often described in science classes.  With that said, it is vital that you learn how to create testable hypotheses, to design and conduct controlled experiments and to use mathematics (statistics) to test your hypotheses.  In this exercise, you will do all of these on a small scale so that you can use it as a model for the research project that you will design, conduct, and present at the research exhibit in April.


Next, students participate in an online forum discussion about the following objectives.



I provide them with a pacing guide to help organize their work:



They then need to get up to speed by reading some background material and choosing videos from a playlist. Here is a copy of the document.

Students choose three the following to watch or read.

Title with link

Notes

Format

Cellophane method

Measure the size of foam

Watch

Balloon method

Measure the size of balloon

Watch

Submerged pipette method

Small scale, count the bubbles

Watch

Mass method

Precise, but needs scales

Watch

Syringe method

Good background information

Read

Inverted tube method

Accurately measure volume of gas produced

Read

Students then design their own experiment based on the methods presented in the playlist. Here is a document I wrote to help them with the essentials of experimental design.

Next, students propose their designs to their classmates and get feedback. At this point, I encourage them to join with other students with similar designs. They revise their experiments, conduct them, collect results, analyze and present them in a Flipgrid presentation that I grade.


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