Fusion of two motile gametes which are dissimilar in size is termed as

Options

A. oogamy
B. isogamy
C. anisogamy
D. zoogamy

Explanation

To solve the question "Fusion of two motile gametes which are dissimilar in size is termed as," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Terms**:
- We need to analyze the terms provided: Oogamy, Isogamy, Anisogamy, and Zoogamy. Each term describes a different type of gamete fusion.

2. **Identify Gamete Characteristics**:
- The question specifies that the gametes are motile (able to move) and dissimilar in size. This is crucial for determining the correct term.

3. **Analyze Each Term**:
- **Oogamy**: This refers to the fusion of a motile male gamete and a non-motile female gamete. Since one of the gametes is not motile, this term does not fit.
- **Isogamy**: This describes the fusion of two similar gametes, which contradicts the requirement of dissimilar size. Therefore, this term is also not applicable.
- **Zoogamy**: This term generally refers to the fusion of gametes in animals but does not specify the size or motility characteristics needed.
- **Anisogamy**: This term specifically refers to the fusion of two motile gametes that are dissimilar in size. This matches the criteria given in the question.

4. **Conclude the Answer**:
- Based on the analysis, the correct term for the fusion of two motile gametes that are dissimilar in size is **Anisogamy**.

### Final Answer:
The fusion of two motile gametes which are dissimilar in size is termed as **Anisogamy**.

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