While Robert Hooke discovered the cell in 1665, the first cell theory didn't come about until the 1830s. The video explains the discovery of the cell and the scientists involved. It continues to the parts of cell theory and the...

Eukaryotes—were we born from an act of predation that backfired? Ponder this and other questions of evolution with a video from a well-written biology playlist. Topics include the origins of mitochondria and chloroplasts, unusual...

Where would we be without bacteria? As it turns out, we owe them everything! Introduce young biologists to endosymbiotic theory using an amazing video from an extensive biology playlist. Scholars discover the bacteria that may be...

Robert Koch and his team of scientists identified the germs that cause diphtheria, typhoid, pneumonia, gonorrhea, meningitis, whooping cough, tetanus, plague, leprosy, syphilis, and more—that's some important work! Over a period of 100...

An analysis of launched objects helps scholars understand general relativity in greater detail. These aren't just any launched objects, though! A video presentation describes the gravitation potential energy of satellites in orbit and...

How did life on earth begin? Is there a scientific explanation that could show how life arose from chemical reactions? Discover the answers to these questions and more as you watch a basic explanation of the hypotheses currently being...

Learn about the basics of the mechanism of evolution and the importance of natural selection, and examine evidence showing that we are seeing evolution playing out in every organism we encounter. In an engaging and easy-to-follow video,...

Journey into the world of the unseen! Learners discover how even the simplest of objects moving at a distance without physical interaction or direction was a problem that mystified scientists for hundreds of years. The narrator explains...

Do young scientists know that some traits are only passed down by the mother? Mitochondrial DNA is an interesting phenomenon that provides researchers with a lot of useful information. Scholars learn about the endosymbiotic theory, what...

Consider a question that baffles even scientists. Why are leaves green? The video lesson offers a theory that begins with the first aquatic plants. Learners consider alternative explanations as well.

Insects developed wings and the ability to fly earlier than any other animal—when exactly did that happen? Scientists know this fact but struggle to explain when insect wings developed and how this entirely new structure appeared. PBS...