The document discusses absorption of digested foods in the ileum. It includes instructions to draw and label a diagram of a transverse section of the ileum under a light microscope, showing the mucosa and muscle layers. It also asks to explain the structural features of an epithelial cell in a villus as seen in electron micrographs, including microvilli, mitochondria, pinocytotic vesicles and tight junctions. Finally, it requests an explanation of the mechanisms used by the ileum to absorb and transport food, such as facilitated diffusion, active transport and endocytosis, and to list materials not absorbed and egested, including cellulose, lignin, bile pigments, bacteria and intestinal cells.