Basis of differentiation | Red blood cells | White blood cells | 
Definition  | biconcave shaped cells found in blood, transports oxygen and co2 to and from the lungs  | cell that function as immune cells, fights infections and injury  | 
Also known as  | Erythrocytes  | Leukocytes  | 
Color  | Red due to presence of hemoglobin  | Colorless  | 
Shape  | Biconcave, discoid shape  | Irregular shape  | 
Size  | Small- range in size from 6 µm to 8 µm in diameter  | Large – range in size from 12 µm to 17 µm in diameter  | 
Nucleus  | Absent on maturity  | Large central nucleus  | 
Components  | Hemoglobin  | Antibodies with the presence of major histocompatibility complex (MHC) antigen cell markers  | 
Function  | Transport oxygen from the lungs to the peripheral tissues in the body and transport carbon dioxide from the tissue to the lungs for elimination  | Produce antibodies to protect the body from disease-causing microbes  | 
Origin  | Red bone marrow  | Red bone marrow, spleen, and lymph nodes  | 
Lifespan  | About 120 days  | About 12 – 20 days  | 
Types  | One types  | Many types: 
  | 
Percentage of human blood  | Make up about 36% to 50% of human blood  | Make up about 1% of human blood  | 
Count per mm3of blood  | 5 million/ mm³ of blood  | 7000–8000/mm³ of blood  | 
Condition caused by low count  | Anemia  | Leukopenia  |