Phagocytosis is not done by –
**Core Concept**
Phagocytosis is a process by which **phagocytic cells** engulf and internalize particles, bacteria, or dead cells. This process is crucial for **immune defense** and **tissue homeostasis**. Cells capable of phagocytosis include **neutrophils**, **macrophages**, and **dendritic cells**.
**Why the Correct Answer is Right**
Since the options are missing, let's discuss the general concept. Phagocytosis is typically performed by specialized cells of the **mononuclear phagocyte system** and **polymorphonuclear leukocytes**. The correct answer would likely be a cell type that does not typically engage in phagocytosis, such as **red blood cells** or **platelets**.
**Why Each Wrong Option is Incorrect**
Without specific options, we can't directly address each choice. However, we can say that cells like **neutrophils** and **macrophages** are incorrect because they are primary phagocytic cells.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that defects in phagocytosis can lead to recurrent infections, as seen in **chronic granulomatous disease**, where **neutrophils** cannot produce reactive oxygen species necessary for killing ingested microbes.
**Correct Answer:** D. Red Blood Cells