FIGURE 7-7 Variation in biomembranes in different cell types. (a) A smooth, flexible membrane covers the surface of the discoid erythrocyte cell, as seen in this scanning electron micrograph. (b) Tufts of cilia project from the ependymal cells that line the brain ventricles.

[Part (a) Omikron/Science Source. Part (b) iophoto Associates/Science Source.]