Photosynthesis is absent in

Options

A. Photic layer
B. Aphotic layer
C. Benthic laryer
D. Pelagic layer

Answer

To determine where photosynthesis is absent among the given layers (photic layer, aphotic layer, benthic layer, and pelagic layer), let's analyze each layer step by step:

### Step-by-Step Solution:

1. **Understanding the Photic Layer:**
- The photic layer is the upper layer of a body of water that receives sunlight.
- Since sunlight is available, photosynthesis occurs in this layer.
- **Conclusion:** Photosynthesis is present in the photic layer.

2. **Understanding the Aphotic Layer:**
- The aphotic layer is the deeper layer of water that does not receive sunlight.
- Without sunlight, photosynthesis cannot occur.
- **Conclusion:** Photosynthesis is absent in the aphotic layer.

3. **Understanding the Benthic Layer:**
- The benthic layer refers to the lowest layer of a body of water, which can be either in the photic or aphotic zone.
- If it is in the photic zone, it can receive light and support photosynthesis. However, if it is in the aphotic zone, it will not.
- **Conclusion:** Photosynthesis can occur in the benthic layer if it is in the photic zone, but may be absent if it is in the aphotic zone.

4. **Understanding the Pelagic Layer:**
- The pelagic layer is the open water column away from the shore.
- This layer can also receive sunlight, especially in the upper parts, allowing for photosynthesis.
- **Conclusion:** Photosynthesis occurs in the pelagic layer.

### Final Answer:
Based on the analysis, the layer where photosynthesis is absent is the **aphotic layer**.