Answer:
The red blood cell?
Step-by-step explanation:
Because the red blood cell is known to have a specific structure, it exhibits a round appearance. Its structure will only change when the body suffers from a lack that alters its form or structure.
What's the red blood cell?
"A type of blood cell that is made in the bone marrow and found in the blood. Red blood cells contain a protein called hemoglobin, which carries oxygen from the lungs to all parts of the body."
-National Cancer Institute (.gov)