In this screencast, learners examine the kinds of physical and chemical changes that occur in substances.

In this animated activity, learners explore three major methods of heat transfer and practice identifying each. This is the animated version with no audio.

In this learning activity you'll review how every protein molecule of an organism is synthesized by that organism in a prescribed process. This activity helps students understand the fundamental life process of making protein.

In this animated learning object, students examine the life cycles of a virus.