Many kinds of prokaryotes and eukaryotes contain a structure outside the cell membrane called the cell wall. With only a few exceptions, all prokaryotes have thick, rigid cell walls that give them their shape. Among the eukaryotes, some protists, and all fungi and plants, have cell walls.
<span>Crop
is the part of the digestive system you would see in a cross-section anterior
to the gizzard in a worm. Crop is a thin wall organ that acts as a temporary food
storage chamber. The esophagus leads to the crop and the organ next to it is
the gizzard which serves as the food grinding chamber.</span>