1 - 12 of 51 results
Citric Acid Cycle

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.

Electron Transport Chain

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.

ATP Synthesis

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.

Mystery of the Missing Tusks

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.

The Science of an Extreme Animal Athlete

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.

Photosynthesis

This multipart animation series explores the process of photosynthesis and the structures that carry it out.

Why Two Heads?

This activity explores images of planarians regenerating missing body parts, which serve as phenomena for learning about cell division and differentiation.

Stalking the Genetic Basis of a Trait

This activity supports the film Popped Secret: The Mysterious Origin of Corn. Students analyze data on the expression of the tb1 gene to explain how variations in this gene played a role in the evolution of corn.

Genetic Mutations and Disease

This interactive module explores how mutations arise in germline and somatic cells. It also shows how these mutations can lead to genetic conditions, such as cystic fibrosis and cancer.

Selective Breeding in Maize

This activity guides the analysis of a published scientific figure from the world’s longest-running controlled artificial selection study, in which scientists tested whether they could use selective breeding to change the protein concentration of maize (corn).

Written in Chalk

This activity explores images of chalk formations and coccolithophores, which serve as phenomena for learning about the interactions between biological and geological processes.