It's late on Saturday, and I just snuck down to the administration area, pilfered some sheets of coloured paper from the Microbiology Dept, and ran them through a shredder belonging to one of the secretaries. Now I have a big cardboard box full of skinny strips of coloured paper to take to Monday's class.
Why? Because on Monday my students will need to learn how mitosis works, which I hope will prepare them for Wednesday and Friday, when they'll need to come to grips with meiosis. By using paper strips as pretend chromosomes, they'll be able to model what chromosomes actually do. Because the strips are coloured, they'll be able to keep track of chromosomes of different types, or with different histories. And because the strips are paper, they'll be able to write the names of alleles onto them.
In the following weeks we'll be doing genetics. I think that most students find genetics difficult primarily because they don't understand meiosis. One reason for this is that they usually encounter it as a series of 'stages', artificially frozen images of what is really a continuous process. Each stage has a name to be memorized, as does each feature of each image. Students have a hard time connecting these static stages with the genetic consequences of meiosis. Watching an animation of the process (even the lovely ones our textbook company has provided) isn't much help.
By encouraging the whole class to use these paper strips simulate mitosis and meiosis for themselves, I hope they'll more easily remember what these processes accomplish. By then having them repeat the simulations with chromosomes labeled with their alleles, I hope they'll come to see how Mendel's 'Laws' are simply an inevitable consequence of what the chromosomes do in meiosis.
Students often mistakenly think that activities like this are babyish, and that as university students they should put away such childish pastimes and settle down to the serious business of learning from books. But I tell them that we're at the frontiers of our abilities here, so we need to use every resource we can to help us understand. This includes a lot of drawing coloured pictures and playing with bits and bobs.