Which of the following is a monogenetic parasite (has only host in its life cycle) ?

Options

A. Wuchereria bancofti
B. Ascaris
C. Plasmodium vivax
D. Both (A) and (B)

Answer

To solve the question "Which of the following is a monogenetic parasite (has only one host in its life cycle)?", we will analyze each of the provided options step by step.

### Step 1: Understand the term "monogenetic parasite"
A monogenetic parasite is one that has only one host in its life cycle. This means that the entire life cycle of the parasite occurs within a single host organism.

### Step 2: Analyze the options
We have four options to consider:
1. **Wuchereria bancrofti**
2. **Ascaris**
3. **Plasmodium vivax**
4. **Both A and B**

### Step 3: Evaluate each option
- **Option 1: Wuchereria bancrofti**
- This is a digenetic parasite, meaning it requires two different hosts to complete its life cycle. It typically involves a mosquito as a vector and a human host. Therefore, this option is incorrect.

- **Option 2: Ascaris**
- Ascaris lumbricoides (commonly known as roundworm) is a monogenetic parasite. It completes its life cycle in a single host, which is typically a human. Therefore, this option is correct.

- **Option 3: Plasmodium vivax**
- This is also a digenetic parasite. It requires two hosts: a mosquito (as a vector) and a human. Thus, this option is incorrect.

- **Option 4: Both A and B**
- Since option A (Wuchereria bancrofti) is incorrect (digenetic) and option B (Ascaris) is correct (monogenetic), this option is also incorrect.

### Conclusion
The only correct answer is **Ascaris**, as it is the only monogenetic parasite listed among the options.

### Final Answer
**Ascaris** is the monogenetic parasite that has only one host in its life cycle.

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