Note: I recommend that you first check out this resource in order to get the most out of this lesson!
In high school I took several drafting classes and, for a while, I had hoped to become an architect. With respect to planning instruction and teaching, I feel that I can still live out the detailed approach to building something intricate and complex even though the product is a lesson rather than a certain "built environment".
The lesson-planning document that I uploaded to this section is a comprehensive overview of how I approach lesson planning. This template includes the "Big Three" aspects of the NGSS standards: Disciplinary Core Ideas, Crosscutting Concepts, and Science Practices. Of course, there are many other worthy learning goals, skills, instructional strategies, and assessments that can be integrated into a class session. I don't feel compelled to check every box but, rather, use it as a guide to consider various options and tailor the lesson in light of these.
With regard to this particular lesson...
I hope you get some value from my work!
Overview of Purpose & Process: Before beginning the lab, I typically like to frame the lab (again for those who may have forgotten a key detail or two or to help students understand a helpful lab technique). Therefore, I review the objective(s) of the lab activity and present and name all equipment for ease of use during lab. This year I added the feature of putting some salt water into the mouthwash (water) to swirl out the cheek cells in order to increase the yield a bit. This is not so pleasant tasting but I think it helps get the most DNA in the end. Lastly, I solicit any questions that students might have prior to starting.
Teaching Challenge #1: How do I develop routines and procedures to support students to work independently in the science classroom?
Teaching Challenge #2: How can I develop a classroom culture that encourages student engagement, curiosity, and a desire to understand the world through scientific exploration?
As I explained in Part #1, these two interrelated challenges may not be entirely solved or conquered by this activity, however this activity represents several steps along the year-long journey (over which I get to accompany the student) and extending beyond my class. I hope that these experiences build toward a larger sense of independence and curiosity as they become adults.
In particular, I think I can get in the way of students learning by trying to "save them" from every little mishap or explain things to a level of minutiae that is overboard. So in this sense, if students are reasonably mature and have an approved plan then what is my role? I generally sit in one corner of the class in my director's chair for a time to simply watch what is going on. It is very insightful to study the dynamics and hear the conversations that are ongoing. To me this is a cool and authentic measure of true learning. I don't know how aware they are of what I am doing but I'll switch from observe mode to Q & A mode (generally once they are in a groove and have had a chance to start collecting data). So for the duration of the lab I am intentionally playing a minor role (and am available for clarifying questions, to celebrate cool happenings, and be on safety patrol).
With about ten minutes left in class, I direct students to clean up and return to their seats when finished. Those teams that finish early should work to finish the lab write-up, including a picture of their DNA sample!
Plus-Minus-Interesting (PMI): As a way to review the process and end result of this cool lab experience, I randomly call on three students to sum things up by sharing their experience through the lens of PMI; in other words self-assessment.
Typically I get answers like:
(P): "The DNA was really cool and looked like jelly or a cloud."
(M): "The salt in the mouthwash was disgusting!"
(I): "I didn't know that we could actually see the DNA molecule (without a microscope)."