The video is a lecture on convex lenses, explaining the way they work to bend and focus light. The speaker defines what a lens is, describes how convex lenses function, explains how to construct a ray diagram with a convex lens, and...

Muscles and movements of the shoulder girdle.

This nugget describes the organs that form the digestive systems of earthworm, cockroach and frog.

Anatomy and function of the main organs of the digestive system.

Atmosphere Set: 1. This clip examines the chemical composition and the layers of the atmosphere.