The toxic substance causing malaria is

Options

A. Sporozoite
B. Haemozoin
C. Cryptozoite
D. Gametocytes

Answer

To answer the question about the toxic substance causing malaria, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Malaria**: Malaria is a disease caused by the Plasmodium protozoan, which is transmitted through the bite of infected female Anopheles mosquitoes.

2. **Identifying the Options**: The question provides four options:
- A. Sporocyte
- B. Hemozoin
- C. Cryptocyte
- D. Gametocyte

3. **Analyzing Each Option**:
- **Option A: Sporocyte** - This is an inactive form of Plasmodium and does not cause infection. Therefore, it is not the toxic substance causing malaria.
- **Option B: Hemozoin** - Hemozoin is a biocrystal produced when Plasmodium digests hemoglobin in red blood cells. This substance is toxic and is responsible for the symptoms of malaria, including fever. Thus, this is a strong candidate for the answer.
- **Option C: Cryptocyte** - This term refers to all malarial parasites. While they can cause malaria, they are not a toxic substance.
- **Option D: Gametocyte** - These are cells that produce gametes for sexual reproduction in the Plasmodium lifecycle. They are not toxic substances.

4. **Conclusion**: After analyzing all the options, it is clear that the toxic substance causing malaria is **Hemozoin**.

### Final Answer:
The toxic substance causing malaria is **Hemozoin**.

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