Ever think about flipping your classroom? This is a whiteboard animation on Genetic Engineering. I created and used this as a part of my own flipped classroom. It is available for download so that you may add in your own commentary as you see fit. Students truly enjoy watching videos more if they feel like it is their own teacher delivering the instruction.
If you would like to see what kind of commentary I have added on my rendition of the video, you may watch it here: https://www.youtube.com/watch?v=4YI5BKa-tDo