Which of the following structures are vestigial in python but not in human?

Options

A. Nictitating membrane
B. Ear pinna
C. Hind limbs
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding Vestigial Structures**:
- Vestigial structures are remnants of organs or structures that had a function in an early ancestor but are no longer functional or have reduced functionality in the current organism.

2. **Identifying the Organisms**:
- The question compares vestigial structures in pythons (reptiles) and humans (mammals).

3. **Analyzing the Options**:
- **Nictitating Membrane**:
- In pythons, the nictitating membrane is functional and helps protect and moisten the eye.
- In humans, it is vestigial as it no longer serves a purpose.
- **Ear Pinna**:
- The ear pinna is present and functional in humans, aiding in sound collection and balance.
- In pythons, it is absent, so it cannot be considered vestigial in them.
- **Hind Limbs**:
- Pythons have remnants of hind limbs that are non-functional, making them vestigial.
- In humans, hind limbs are functional and essential for walking.

4. **Conclusion**:
- The only structure that is vestigial in pythons but not in humans is the **hind limbs**.

**Final Answer**: Hind limbs are vestigial in pythons but not in humans.

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