This animation shows how the proton gradient across the mitochondrial membrane powers the ATP synthase enzyme to make ATP. It is the third of three animations about cellular respiration.
This animation shows how the enzyme complexes of the electron transport chain harvest energy from cofactor molecules to pump protons across the mitochondrial membrane and establish a chemical gradient. It is the second of three animations about cellular respiration.
This animation shows the reactions of the citric acid cycle, which splits off carbon atoms and generates energy-rich reduced forms of cofactor molecules. It is the first of three animations about cellular respiration.
This activity explores images of elephants with and without tusks, which serve as phenomena for learning about selection and human impacts on the frequency of traits within populations.
In this video, ecologist Tony Sinclair takes us through the steps of how he uncovered that the eradication of an infectious disease in cattle led to a boom in the Serengeti’s buffalo and wildebeest numbers.
This video follows biologist Shane Campbell-Staton, who is studying the adaptations that allow deer mice living at high elevations to stay warm and active during the winter.
This film explores the species-area relationship, a general ecological rule that describes how the number of species in a habitat changes with area, and shows how it has been applied to the conservation of protected areas.
This activity explores images of bats with an infectious fungal disease, which serve as phenomena for learning about population dynamics and disease impacts.
This activity builds on information presented in the video Selection for Tuskless Elephants. Students use scientific evidence and reasoning to construct an explanation of and develop an argument for tusklessness in elephant populations.