Final answer:
The leukocyte described, with two large lobes in the nucleus and prominent rosy to orange granules in the cytoplasm, is known as an eosinophil. This type of white blood cell is particularly noticeable in blood tests due to its affinity for acidic stains, which highlights its granules.
Step-by-step explanation:
The leukocyte described in the question is called an eosinophil. It is characterized by a nucleus that commonly has two large lobes and a cytoplasm filled with abundant rosy to orange-colored granules. The specific coloration of eosinophil granules comes from their affinity for acidic stains, particularly an acidic dye named eosin.
Eosinophils typically represent 2-4 percent of the total leukocyte count in the bloodstream. They measure approximately 10-12 µm in diameter. The identification of eosinophils can be significant to diagnose conditions like allergies, parasitic infections, and autoimmune diseases. Their granules are somewhat larger than those of neutrophils and stain with the reddish-orange hue due to eosin, giving them the characteristic color that can be easily spotted in blood smears under the microscope.