I’ve just about finished teaching Topic 8 to my Upper 6th Biology students and I’ve been using a left-over 2m length of DNA model that my Y11s made to learn about DNA structure. I’ve cut it up with scissors to show how restriction endonucleases work, and mended it over and over again with sellotape to show how DNA ligase works. I’ve butchered a bit to make a probe (with a yellow circle of card stapled to it) and a primer. It’s looking in a sorry state now but I think it’s made a HUGE difference to how my students have understood chapter 21 compared to the previous two years. I’m giving some consideration to making a permanent model using felt shapes and velcro.
Here are the templates and the powerpoint I use with Year 11 to build it in the first place. The template has instructions for our wonderful reprographics queen, Ali, which will do for a class of 20 but you’d need to scale up or down accordingly for your classes (and the colours don’t actually matter of course!)
Resources:
Pedagoggles 