Would you (or your students) appreciate an online overview of biology created by the funny and talented Hank Green? Then check out Hank’s 40-part Crash Course in Biology. Each lesson consists of a short (10-15 minute) YouTube video. The entire course is 7 hours but can easily be searched and used by specific biology content. See That’s Why Carbon is a Tramp: Crash Course Biology #1 embedded below. This would be most useful for high school students or college students looking for a review or refresher of life science concepts.
By the way, Hank also has a Crash Course in Ecology.