Biology 3rd Edition by Peter Russell, Paul Hertz, Beverly McMillan

Exercise 8

Which of the following contributes to the sealed lining of the digestive tract to keep food inside it?
A)central vacuole that stores proteins
B)tight junctions formed by direct fusion of proteins
C)gap junctions that communicate between cells of the stomach lining and its muscular wall
D)desmosomes forming buttonlike spots or a belt to keep cells joined together
E)plasmodesmata that help cells communicate their activities