Both ends of the sporozoite are equally pointed. One end of the sporozoite is more pointed than the other. The sporozoite glycoprotein specifically activates mast cells. "Babesia" species enter red blood cells (erythrocytes) at the sporozoite stage. Once inside the cell, the sporozoite loses its outer coating. The parasitic, infectious cell that infects a host is called a sporozoite. Once infecting the host organisms cell, the sporozoite begins feeding and growing. Each sporozoite attaches to a red blood cell, and moves inside the cell. The sporozoite attaches to or penetrates the intestinal wall. The "P. vivax" sporozoite enters a hepatocyte and begins its exoerythrocytic schizogony stage.