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 short article is an U.S. Fish and Wildlife Service fact sheet about Ursus maritimus, the Polar Bear. It covers basic information, including: appearance, feeding habits, reproduction, adaptations, and protection.