the donughnut shape of the red blood cells is specificly for the oxygen molocule. The blood comes back into the heart from the lungs in the pulmonic artery. and the oxygen molocule sits in the donoughnut hole like a seat cussion.
They are shaped like that because they were naturally formed like that and blood cells carry oxygen and other resources you need to survive.
A white blood cell is not toroidal. (Doughnut shaped)
erythrocytes
Well, it's red from hemoglobin inside the cells. It looks like a circle with a dent in the middle, sort of like a donut.
crescent shaped blood cells are from sickle cell anemia
Sickle cells. Sickle cell anemia is the disease characterized by sickle-shaped blood cells.
red blood cells
The shape of frog's blood cell is usually an oval and slightly small shape.
poikilocytosis
The red blood cells that transport oxygen in the blood are circular in shape with the center compressed - kind of like a donut, but where the hole would be is a "well" of tissue. It is shaped like this because this shape increases the surface area of the cell and allows it to carry more oxygen. The shape makes it more efficient.
a torus
red blood cells are disc shaped while white blood cells have no permanent shape.
red blood cells have a biconcave shaped
A doughnut (donut).