This lesson focuses on the diffusion of gas molecules across the cuticle membrane of sea spider legs and the role body size plays in the ability of sea spiders to uptake gases. Students construct model sea spider legs of varying diameters and use them to investigate the relationship between surface area-to-volume ratios and diffusion.
This detailed animation shows how the Earth is lit by the Sun throughout the year. The lighting of the Arctic and the Antarctic is detailed for every month of the year to help explain, among other things, the resulting polar night.
The animation is available in the following languages: