Epithelial cells grow close together to form the body's .

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins

In "the pig," what is the main effect that the piglet initially has on kibuka?

Describe the relationship between isotonic solutions, equilibrium, and water movement into and out of a cell.