I use Mr. Andersen's videos all the time in my AP Biology class as a precursor to my lectures. This is my write-a-long, or WAL as I call them, for his "Gene Regulation" video.
My WAL is broken into the sections shown within the video (terminology/intro, lac operon, trp operon, eukaryotic regulation) and is mainly fill-in-the-blank for students while the video plays. However, in two places (once near the end of the WAL, and once at the very end of the WAL), I include some higher-level application/summary questions to get students to really THINK about what they watched in the video. Students watching this video should have basic familiarity with positive and negative feedback loops and the differences between eukaryotes and prokaryotes to be able to complete the summary questions.
Please note that there is no key included with this product. It's good for you to watch the video so you know what your students will see, anyway :)