Final answer:
The WBC reference range for adults is typically between 3.5 to 11 x 10⁹ cells/L. White blood cells are crucial for the immune system, and changes in their count can indicate an immune response to a disease.
Step-by-step explanation:
The WBC reference range for adults, which measures the healthy amount of white blood cells, is typically between 3.5 to 11 x 10⁹ cells/L. These cells are crucial for defending the body against infections and are part of the immune system. The count can be measured in different units, such as cells per microliter of blood; for primates, a common reference range is 4,800 to 10,800 cells per µl. Notably, values for white blood cells can vary across different animals. When there is a departure from these normal values, it may indicate an immune response to a disease. This can be observed through increased or decreased WBC counts relative to the established normal values for the individual's species.