Which of these aptly describes a zygote?

Options

A. A single-celled structure
B. A female gamete
C. A male gamete
D. A mass of cells

Explanation

**Step-by-Step Solution:**

1. **Understanding Gametes**:
- Gametes are the reproductive cells involved in sexual reproduction. In animals, there are two types of gametes: male gametes (sperms) and female gametes (ova or eggs).

2. **Fertilization Process**:
- Fertilization occurs when a male gamete (sperm) fuses with a female gamete (ovum) in the female reproductive system, specifically in the fallopian tube.

3. **Formation of Zygote**:
- The fusion of the sperm and ovum results in the formation of a zygote. This is a crucial step in reproduction as it marks the beginning of a new organism.

4. **Characteristics of Zygote**:
- A zygote is formed from the fusion of two gametes, resulting in a single cell that contains genetic material from both parents. This makes the zygote a single-celled structure.

5. **Conclusion**:
- Based on the definitions and processes described, the correct description of a zygote is that it is a single-celled structure.

**Final Answer**: A zygote is aptly described as a single-celled structure.

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