Time for Student Lesson One
This lesson will take three-45 minute periods.
Encourage students to generate questions beyond the ones offered as they look at the flies. Remind them to write these in their journal. At the end of the first day, they could be amassed on the chalkboard or butcher paper for further discussion or, as an extension, assigned to student groups to research and answer later.
Part 2: A closer look
Part 3: Life cycle of the fruit fly
Part 4: Parts
of the fly: external anatomy
Be sure students are not looking at virgin or immature flies as these characteristics are quite different.
Part 5: How to tell males from
shape of the posterior end of the abdomen is very significant. Males are rounded whereas females are more
Check that students have correctly sexed their flies. It is important that all group members know how to do this in case one is absent when making crosses.
Refer to An Introduction to Drosophila melanogaster on techniques to anesthetize flies.
Student groups should keep their flies vials together. Remind them to write the date and fly type on the vials. (You could ask them what is needed on the vial and have the class come up with ideas instead of telling them). At the end of this lesson, students should have two vials of wild-type flies. You may want them to make cultures of mutants at this time, also, or wait until lesson two.
Part 7. Assessment
1. Drawing the external anatomy
Each student needs to have their own drawing to refer to and permanently placed in their Drosophila journal.
Are all parts of the flys anatomy present?
Is it drawn to scale?
Are the colorations accurate?
Is it neatly drawn?
2. Differences between male and females
Are the descriptions accurate?
Are several differences included?
Is the drawing of the abdomens (ventral and dorsal):
3. Sexing flies
How many times did it take for the student to get it right? A verbal assessment is recommended at this point; however reinforce the idea that it is of vital importance to be able to distinguish the difference between the two when making crosses.
Is the entry complete? Is there a synopsis of what they did each day?
5. Additional assessment to check student understanding on:
The University of Arizona
Department of Biochemistry and Molecular Biophysics
General Biology Program for Secondary Teachers