Using text and graphics, this learning activity describes a sine wave, including alternations, cycles, time, amplitude, and degrees

In this interactive object, learners study animal estrous cycle lengths. They then test their knowledge in three exercises.

In this animated object, learners examine cycles, frequency, Hertz, wavelengths, and periods. A brief quiz completes the activity.

In this animated activity, learners examine the operation of a pneumatic cylinder that continuously cycles by extending and retracting.

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

In this animated activity, sexual reproduction in animals is contrasted with the alternation of generation lifecycle of plants.