Unraveling Multiple Representations of Chromosomes to Reveal Student Thinking

Presenter: Kim Parfitt, 3DMD

Saturday, July 23rd - 1:00 - 2:00pm

Participants will assess their biggest challenge areas with respect to student misconceptions about chromosome structure and function, including mitosis. Traditional wet labs like planaria, fruit fly genetics, and C-fern growth will be used to contextualize the hands-on models’ utility throughout the school year. 
Next, foam puzzle chromosomes will be introduced and used to model a round of DNA replication in the cell cycle, resulting in 4 chromosomes. The processes of mitosis and meiosis will be modeled and compared, to invite inquiry about why the processes are different.
Whole chromosomes will be related with molecular chromosome details to illustrate how DNA is wound into a chromosome structure. Nucleosome models will further highlight the wrapping of DNA around histone proteins to compact the genome for replication.  
Participants will be asked to share how they teach about genetic variation in their classes. Following a discussion of their challenges, we will model variation first using the puzzle chromosomes to generate “crossing over” events and next by using the molecular-detailed expanded chromosomes. 
Finally, inheritance of Hemoglobin will be highlighted and modeled and Punnett squares models will be enhanced through using the foam models. Throughout the activities, participants will be invited to engage in self-reflection and collaborative discussion.