Biology: Predator-prey cycles

What effect do interactions between species have on the sizes of the populations involved? Learn about the dynamics of predator and prey populations, and how they can influence one another’s patterns of growth and decline. 

Biology

Life is beautiful! From atoms to cells, from genes to proteins, from populations to ecosystems, biology is the study of the fascinating and intricate systems that make life possible. Dive in to learn more about the many branches of biology and why they are exciting and important. Covers topics seen in a high school or first-year college biology course.

Population growth & regulation

Any species could take over the Earth just by reproducing if it had unlimited resources. That includes bacteria, worms and snakes, which might not be things you want covering the Earth's surface in a four-foot layer! Learn how populations grow and why real populations in nature always have limits on their growth.

Topic: Science

Learn about all the sciences, from physics, chemistry and biology, to cosmology and astronomy, across hundreds of videos, articles and practice questions.