Final answer:
Lymphocytes have a round, densely stained nucleus with a small amount of cytoplasm, staining darkly with Wright stain and standing out under microscopic examination due to their large, centrally located nucleus.
Step-by-step explanation:
The class of cells that have a round, densely stained nucleus with a small amount of cytoplasm are known as lymphocytes. These cells are part of the immune system and can be seen in both large and small variants, including natural killer (NK) cells, B cells, and T cells. Lymphocytes absorb Wright stain well, which is why they appear dark under a microscope. The presence of a large, centrally located nucleus occupying much of the cell's volume is a defining characteristic of these cells. Furthermore, they have negligible amounts of cytoplasm compared to the size of their nuclei. Descriptions of these cells have been observed at magnifications of 1000 times and characterized with a typical blue or dark purple color when stained.