Which one is not a vestigal structure in humans

Options

A. Epiglottis/Intestine
B. Vermiform appendix
C. Wisdom teeth
D. Body of hair.

Answer

To determine which structure is not a vestigial structure in humans, we need to understand what vestigial structures are and analyze the options provided.

### Step-by-Step Solution:

1. **Define Vestigial Structures**:
Vestigial structures are anatomical features that were functional in our ancestors but have lost their original function in modern humans due to evolutionary changes.

2. **Analyze the Options**:
We need to look at the options provided and identify which one is still functional in humans.

3. **Evaluate the Epiglottis**:
The epiglottis is a flap of tissue that covers the trachea during swallowing to prevent food from entering the airway. It is an essential structure for protecting the respiratory tract and is still functional in humans.

4. **Evaluate the Intestine**:
The intestine is crucial for digestion and absorption of nutrients. It plays a vital role in the digestive system and is not vestigial.

5. **Evaluate the Vermiform Appendix**:
The vermiform appendix is considered vestigial as it was useful in our ancestors for digesting cellulose from raw plant material, but it has lost its significant function in modern humans.

6. **Evaluate Wisdom Teeth**:
Wisdom teeth are also considered vestigial because they were useful for our ancestors who had a different diet, but they often cause problems in modern humans due to changes in diet and jaw size.

7. **Evaluate Body Hair**:
Body hair served protective functions in our ancestors, but with the advent of clothing, its role has diminished, making it vestigial as well.

8. **Conclusion**:
Among the options, the epiglottis and the intestine are not vestigial structures. However, since the question asks for one that is not vestigial, the intestine is the most clear example of a non-vestigial structure because it is actively involved in digestion and absorption.

### Final Answer:
**The intestine is not a vestigial structure in humans.**

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