Trophoblasts of Plasmodium feed on

Options

A. Haemoglobin molecules
B. Cytoplasm of erythrocytes
C. Globin part of haemoglobin.
D. Haematin part of haemoglobin.

Answer

### Step-by-Step Solution:

1. **Understanding Plasmodium and its Lifecycle**: Plasmodium is a genus of protozoan parasites known to cause malaria. The most common species responsible for malaria is Plasmodium vivax. The lifecycle of Plasmodium involves transmission through the bite of the female Anopheles mosquito, which injects the infective stage known as sporozoites into the human bloodstream.

2. **Entry into the Host**: After entering the bloodstream, the sporozoites travel to the liver, where they multiply. Once they mature, they enter the red blood cells (RBCs) to continue their lifecycle.

3. **Trophozoite Stage**: Inside the RBCs, the Plasmodium species develop into trophozoites. This is the stage where they actively feed and grow.

4. **Feeding Mechanism**: The trophozoites feed on the cytoplasm of the RBCs. They secrete a digestive enzyme called Lysolizidin, which helps in breaking down the cytoplasmic components of the RBCs.

5. **Hemoglobin Breakdown**: While the trophozoites do interact with hemoglobin, they do not directly feed on it. Instead, they break down hemoglobin into its components, leading to the formation of a pigment called hemozoin. This pigment is a byproduct of hemoglobin degradation and is associated with the pathogenic effects of malaria.

6. **Toxin Production**: The hemozoin produced is considered a pyrogen, meaning it can induce fever. This is why individuals infected with malaria often experience intermittent fevers every 48 to 72 hours.

7. **Conclusion**: Therefore, the trophoblasts of Plasmodium primarily feed on the cytoplasm of the erythrocytes (RBCs) rather than directly on hemoglobin.

### Final Answer:
The trophoblasts of Plasmodium feed on the cytoplasm of the red blood cells (RBCs).

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