Biology library

What this course covers

Khan Academy's Biology library is less a single linear course and more a comprehensive reference — free videos, articles, and exercises spanning the subject, so you can move through it sequentially or jump straight to the topic you're stuck on.

Who it's for

High school and college students running alongside a formal biology class, homeschooling families, or adult learners heading toward healthcare or life-sciences study who want a refresher before diving back in. The breadth of the “library” format means it works equally well as a full course or a targeted lookup tool.

Because the exercises are built in alongside the videos and articles, you get a way to actually check whether a concept landed rather than just passively watching content.

Why grab it: it's free, thorough, and flexible enough to use as either a complete course or an on-demand reference whenever biology comes up.