The receptor absent in tongue is :

Options

A. Thermoreceptor
B. Gustatoreceptor
C. Photoreceptor
D. None of these

Answer

To determine which receptor is absent in the tongue, we can analyze the options provided:

1. **Thermoreceptor**: These receptors are responsible for detecting temperature changes. They are indeed present on the tongue, allowing us to sense hot and cold temperatures. Therefore, this option is incorrect.

2. **Gustatory receptor**: These receptors are specifically designed for taste and are found in the taste buds on the tongue. They help us perceive different flavors. Since these receptors are present, this option is also incorrect.

3. **Photoreceptor**: Photoreceptors are specialized cells that respond to light and are primarily located in the retina of the eye. They are not found on the tongue. Thus, this option is correct as it indicates a receptor that is absent in the tongue.

4. **None of these**: This option suggests that all receptors mentioned are present in the tongue. Since we have identified that photoreceptors are absent, this option is incorrect.

Based on the analysis, the receptor that is absent in the tongue is the **photoreceptor**.

### Final Answer:
The receptor absent in the tongue is the **photoreceptor**.