Which of the following toxic substance is responsible for the malarial fever.

Options

A. Haemocyanin
B. Haemozoin
C. Haemoglobin
D. Haemoriden

Explanation

To determine which toxic substance is responsible for malarial fever, we can follow these steps:

### Step 1: Understand the Malaria Cycle
Malaria is caused by the Plasmodium parasite, which is transmitted to humans through the bite of infected female Anopheles mosquitoes.

### Step 2: Identify the Role of the Mosquito
When the mosquito bites a human, it injects sporozoites (the infective form of the parasite) into the bloodstream. These sporozoites travel to the liver.

### Step 3: Reproduction in the Liver
In the liver, the sporozoites reproduce and multiply. This stage is crucial as it leads to the next phase of the infection.

### Step 4: Release of Toxins
As the Plasmodium parasites multiply in the liver, they eventually enter the bloodstream and infect red blood cells (RBCs). When these RBCs burst, they release a toxic substance known as **hemozoin**.

### Step 5: Identify the Correct Option
Given the options:
1. Hemocyanin
2. Hemozoin
3. Hemoglobin
4. Hemoeridin

The correct answer is **hemozoin**, as it is the toxic substance released during the rupture of RBCs infected by the Plasmodium parasite.

### Final Answer
The toxic substance responsible for malarial fever is **hemozoin**.

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