A: Secondary host of Taenia solium is pig.
R: Malarial parasite completes its life cycle in the blood of human beings alone.

Options

A. If both As and R are correct and R is correct explanation of As
B. If both As and R are correct but R is not correct explanation of As
C. If As is correct, R is wrong
D. If both As and R are wrong.

Answer

To solve the assertion and reason question, we will analyze both statements step by step.

### Step 1: Analyze the Assertion
- **Assertion (A)**: "Secondary host of Taenia solium is pig."
- Taenia solium, commonly known as the pork tapeworm, is a type of flatworm.
- In the life cycle of Taenia solium, humans are the primary host as they harbor the adult tapeworm in their intestines.
- Pigs serve as the secondary host, where the larval form of the tapeworm develops.
- Therefore, the assertion is **true**.

### Step 2: Analyze the Reason
- **Reason (R)**: "Malarial parasite completes its life cycle in the blood of human beings alone."
- The malarial parasite, specifically Plasmodium species, requires two hosts to complete its life cycle: humans and female Anopheles mosquitoes.
- In humans, the parasite undergoes asexual reproduction, while in mosquitoes, it undergoes sexual reproduction.
- Therefore, the statement that the malarial parasite completes its life cycle in the blood of human beings alone is **false**.

### Step 3: Conclusion
- Since the assertion (A) is true and the reason (R) is false, the correct answer is that A is true and R is false.

### Final Answer
- The correct option is **3**: A is true, R is false.

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