Khan Academy
Khan Academy: Plasma Membrane and Cytoplasm
Article takes an in-depth look at the structure and function of the plasma membrane and cytoplasm of cells, the phospholipid bilayer, and microvilli.
Curated OER
Kids Health: Stick Out Your Tongue and Say Aah!
This illustrated tongue tutorial shows that this organ is used for more than just talking (and tongue twisters). Features include Spanish version and links to related human body topics.