Direct Teacher Presentation
This is an example of a DTP (direct teacher presentation) that worked really well to engage students, keep them focused, and give me evidence of learning in the end.
I opened the class by posting the entrance ticket: "Pick two traits that you possess and describe them. Where do you think these traits came from?" Some students were unsure what "trait" meant, so I gave them examples: the way you look, your personality. Students shared their thoughts with a partner and then with the class. As I had hoped, some students attributed their traits to their parents and others to their upbringing. We had a lively class discussion on the nature vs. nurture debate. Students brought up points that previewed some topics I had planned on discussing: traits skipping generations, traits being very different between siblings. This provided a glimpse of the students' prior knowledge, as well as the hook into my DTP.
Download my PPT presentation: Intro to Genetics.ppt
After defining genetics and introducing Gregor Mendel's experimental setup crossing purple and white pea flowers, I asked students to take a blank sheet of paper and describe Mendel's setup, hypothesize the results, and justify their reasoning. When called on to share their hypotheses, some students thought the next generation would be a mix of purple and white flowers, while others thought it would be some in-between color. I revealed the actual results (all purple) and asked the class how this could be explained. Where did the white trait go? After some discussion, I introduced new vocabulary terms and cold-called students to apply these terms to the context of Mendel's experiment. I then described Mendel's next setup, crossing the new purple flowers with themselves, and asked students to write hypotheses regarding this cross. This resulted in another lively round of discussion, especially after I revealed the true results. This segued into an explanation of the genetic mechanisms. At the conclusion, I posted the exit ticket: "Is it possible for two brown-eyed people to have a blue-eyed child?" When students passed in their papers at the end, I had evidence that students were following along and understood the implications of experiments I was describing. They were also excited to return the next day to find out more about how their traits are passed down from generation to generation.