Choose the correct statement/s regarding malaria :
(i) Malignant malaria is caused by plasmodium vivax .
(ii) Frequent chills and fever are caused by hemozoin.
(iii) Sporozoites reproduce sexually in hepatocytes.
(iv) Gametocyte develop in RBCs.

Options

A. i and ii only
B. ii and iii only
C. iii and iv only
D. ii and iv only

Answer

To solve the question regarding malaria, we need to evaluate each of the four statements provided and determine their correctness based on our understanding of malaria and its causative agent, Plasmodium.

### Step-by-Step Solution:

1. **Evaluate Statement (i)**: "Malignant malaria is caused by Plasmodium vivax."
- **Analysis**: Malignant malaria is actually caused by Plasmodium falciparum, not Plasmodium vivax. Plasmodium vivax causes a less severe form of malaria.
- **Conclusion**: This statement is **incorrect**.

2. **Evaluate Statement (ii)**: "Frequent chills and fever are caused by hemozoin."
- **Analysis**: Hemozoin is a byproduct of the digestion of hemoglobin by the Plasmodium parasite. Its accumulation in the body leads to the characteristic chills and fever associated with malaria.
- **Conclusion**: This statement is **correct**.

3. **Evaluate Statement (iii)**: "Sporozoites reproduce sexually in hepatocytes."
- **Analysis**: Sporozoites do not reproduce sexually in hepatocytes (liver cells). Instead, they undergo asexual reproduction in the liver, and sexual reproduction occurs later in the mosquito after the gametocytes are formed in the human host.
- **Conclusion**: This statement is **incorrect**.

4. **Evaluate Statement (iv)**: "Gametocytes develop in RBCs."
- **Analysis**: Gametocytes, which are the sexual forms of the Plasmodium parasite, do indeed develop in red blood cells (RBCs) of the human host.
- **Conclusion**: This statement is **correct**.

### Final Evaluation:
- The correct statements are:
- Statement (ii): Correct
- Statement (iv): Correct
- Therefore, the correct answer is that statements 2 and 4 are correct.

### Answer:
**Option D: Statements 2 and 4 are correct.**

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