Which of these animals follow external fertilization?

Options

A. Frogs
B. Ducks
C. Zebras
D. Humans

Answer

**Step-by-Step Solution:**

1. **Understanding Fertilization Types**: First, we need to differentiate between external and internal fertilization. External fertilization occurs when the sperm fertilizes the egg outside the female's body, while internal fertilization happens inside the female's body.

2. **Identifying the Animals**: The animals mentioned in the question are frogs, ducks, zebras, and humans. We need to analyze which of these animals use external fertilization.

3. **Analyzing Each Animal**:
- **Frogs**: Frogs are known for external fertilization. They lay eggs in water, and the male fertilizes them with sperm outside the female's body.
- **Ducks**: Ducks typically practice internal fertilization. The male duck fertilizes the eggs inside the female before she lays them.
- **Zebras**: Zebras also undergo internal fertilization. The fertilization occurs inside the female's body.
- **Humans**: Humans are another example of internal fertilization, where the sperm fertilizes the egg inside the female's reproductive system.

4. **Conclusion**: Based on the analysis, the only animal from the list that follows external fertilization is frogs.

5. **Final Answer**: Frogs are the animals that follow external fertilization.

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