Final answer:
a. Döhle bodies are small, round, or rod-shaped inclusions found within the cytoplasm of neutrophils and appear on peripheral blood smears when there is infection or inflammation.
Step-by-step explanation:
The question refers to structures that may appear on the periphery of a red blood cell (RBC).
The correct answer from the provided options is a. Döhle bodies. Döhle bodies are small, round, or rod-shaped inclusions found within the cytoplasm of neutrophils, which are a type of white blood cell.
These bodies appear as pale areas adjacent to the cell nucleus and are composed of ribosomal RNA. They are often seen as a sign of infection or inflammation.
In contrast, mycoplasma is a genus of bacteria that lacks a cell wall and may also associate with RBCs but is not the correct answer in this context.
Heinz bodies are inclusions within RBCs caused by denatured hemoglobin, visible with special staining, while Ehrlichia refers to a genus of bacteria that can infect white blood cells.
It is essential to distinguish these entities in blood smear examinations to make accurate diagnoses or inferences about the underlying physiological or pathological processes taking place.