3. Check for Understanding: Play the “Lac Operon” role-play (45 min). 3.1 Introduce the lac operon and trp operon role-play activity and explain the process (5 min). Assign the roles of different molecules to volunteer students who will be the “actors,” while all the
other students will be the “directors” of the play.
3.2 Role-play (15 min): The “actors” play the dynamic regulation of the lac operon, and the “directors”
judge whether they play a functional lac operon or not. Change the environmental conditions, play
the responses of the lac operon again (10 min). If time permits, repeat for the trp operon. (5min)
3.3 Group Discussion (10 min): As a large group, discuss the following questions: •
What are the ways to improve the play by better representing the regulation of the pathway?
•
How would one exhibit specific versus non-specific interactions?
•
What other responses will be stimulated under other conditions, such as mutations?
3.4 Students discuss remaining exercise questions in small groups (15 min). •
Sample exercise question: What do you think would happen in each of the following? •
An E.coli missing a functional lacZ gene.
•
An E.coli missing a functional lacI gene.
•
An E.coli in which the repressor molecule no longer can bind lactose.
4. Summarize the discussion and any remaining questions (10 min). ________________________________
2
Submitted by Yaxuan Yang, Molecular, Cellular & Developmental Biology as a sample lesson from Bio 172 (under the
direction of Dr. Kenneth Cadigan)
42
University of Michigan GSI Guidebook Sample Lesson Plans Continued 50-minute Comparative Politics Class on Modernization Theory 3
