The infective stage of Plasmodium is known as:
(a) sporozoite
(b) gametocyst
(c) merozoite
(d) schizont

Options

A. sporozoite
B. gametocyst
C. merozoite
D. schizont

Explanation

To solve the question regarding the infective stage of Plasmodium, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the infective stage of Plasmodium, which is the stage that enters the host body.

2. **Identify the Options**: The options provided are:
- (a) sporozoite
- (b) gametocyst
- (c) merozoite
- (d) schizont

3. **Define the Stages of Plasmodium**:
- **Sporozoite**: This is the stage that is injected into the human body by the female Anopheles mosquito during a bite. It is the infective form.
- **Gametocyst**: This is a stage that forms in the mosquito and is not the infective stage for humans.
- **Merozoite**: This stage develops after the sporozoite has entered the liver and multiplied. It is not the initial infective stage.
- **Schizont**: This is a stage in the life cycle of Plasmodium that occurs after the merozoite stage and is involved in asexual reproduction.

4. **Conclusion**: Based on the definitions, the sporozoite is the stage that enters the human host and is responsible for initiating the infection. Therefore, the correct answer is (a) sporozoite.

### Final Answer:
The infective stage of Plasmodium is known as: **(a) sporozoite**.

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