In oogamy, fertilization involves

Options

A. A large motile female gamete and a small non - motile male gamete
B. A small non-motile female gamete and a large motile male gamete
C. A large non-motile female and a small motile male gamete
D. A large non-motile female gamete and a small non-motile gamete

Answer

**Step-by-Step Solution:**

1. **Understanding Oogamy**: Oogamy is a type of sexual reproduction characterized by the fusion of two dissimilar gametes. In this case, we focus on the characteristics of the male and female gametes involved in fertilization.

2. **Identifying Gamete Characteristics**: In oogamy:
- The female gamete (ovum) is large and non-motile. This means it does not have the ability to move on its own and is typically larger in size.
- The male gamete (sperm) is small and motile. This means it can move actively, usually due to the presence of flagella, and is smaller in size compared to the female gamete.

3. **Analyzing the Options**:
- **Option 1**: Large motile female gamete and small non-motile male gamete - Incorrect, as the female gamete is non-motile.
- **Option 2**: Small non-motile female gamete and large motile male gamete - Incorrect, as the female gamete is large and non-motile.
- **Option 3**: Large non-motile female gamete and small motile male gamete - Correct, as this matches the definition of oogamy.
- **Option 4**: Large non-motile female gamete and small non-motile male gamete - Incorrect, as the male gamete must be motile.

4. **Conclusion**: Based on the analysis, the correct answer is **Option 3**: a large non-motile female gamete and a small motile male gamete.

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