This video segment from Evolution: "Darwin's Dangerous Idea" illustrates the remarkable camouflage of a praying mantis against its leafy backdrop.

This video from Evolution explores the evolution of humans from a common ancestor of humans, chimpanzees, and other apes.

This video from Evolution highlights Charles Darwin's personal struggle to bring to light his theory of evolution through natural selection.

In this video from Evolution, an exploration of multi-drug resistant tuberculosis in the Russian prison system highlights one reason it is important to understand evolution.

In this video segment adapted from NASA, students in Matsuyama City, Japan, interview Expedition 8 Commander and NASA Science Officer Mike Foale and Flight Engineer Alexander Kaleri about life and work aboard the International Space Station.

In this video segment adapted from ZOOM, the cast investigates how the pitch of sound changes when they strike a variety of glasses filled with different amounts and types of liquids.

Can a fresh lemon power a digital clock? In this video segment adapted from ZOOM, the cast shows you how this can be done and, in the process, discover how kids can be a part of an electric circuit.

Join Tarissa and Sabrina as they measure and compare the volume of different sounds across New York City in this video from DragonflyTV.

In this video segment adapted from Interactive NOVA, astronaut John Young experiences extreme temperatures on the Moon that are a result of the Moon's low gravity and lack of atmosphere.

In this video segment adapted from NOVA scienceNOW, scientists in western Greenland explain how a glacier there is shrinking and moving faster due to increased melting.

This video describes the role of the brain in regulating body temperature and how sometimes fever is employed to fight off infection.

This video segment from the teacher video series Learning That Works uses a case study to highlight the effectiveness of a project-based, real-world approach to teaching science.

This Evolution video segment depicts the landmark hominid fossil finds by Don Johanson and his team in Ethiopia.

In this video segment from Evolution: "Great Transformations," paleontologist Jenny Clack explains that vertebrates evolved fingers before they invaded land.

In this video segment adapted from NOVA, scientists investigate how farming along the Mississippi River impacts floods and what can be done about it.

This media-rich essay from NOVA Online describes the challenges of forecasting volcanic eruptions and includes information about specific cases.

This video segment from NOVA: "The Killer's Trail" investigates the potential for DNA evidence to solve murder cases, even those from the distant past.

This video segment adapted from NOVA shows how scientists use the fossil record to trace when early human ancestors and related species began walking on two legs instead of four, and to determine whether they were more apelike or human in appearance.

In this interactive activity adapted from the University of Utah's ASPIRE Lab, investigate frequency in terms of trampoline jumps, pendulum swings, and electromagnetic waves.