Unipolar neurons with an axon and no dendrite are present in :

Options

A. Embryos
B. Dorsal root ganglia of spinal cord
C. Brain
D. Retina

Explanation

**Step-by-Step Solution:**

1. **Understanding Unipolar Neurons**:
- Unipolar neurons are characterized by having a single axon and no dendrites. This means they have a unique structure compared to other types of neurons, such as bipolar and multipolar neurons.

2. **Identifying Locations of Unipolar Neurons**:
- To answer the question, we need to identify where unipolar neurons are typically found.

3. **Evaluating the Options**:
- **Option 1: Embryos**: Unipolar neurons are indeed present in embryos during early development.
- **Option 2: Dorsal Root Ganglia**: This area primarily contains pseudounipolar neurons, which are a type of unipolar neuron, but they are not strictly classified as unipolar in the same sense as those found in embryos.
- **Option 3: Spinal Cord**: The spinal cord mainly contains multipolar neurons, making this option incorrect.
- **Option 4: Brain**: The brain also contains primarily multipolar neurons, so this option is incorrect as well.
- **Option 5: Retina**: The retina contains bipolar neurons and other types, but not unipolar neurons.

4. **Conclusion**:
- Based on the analysis, the correct answer is that unipolar neurons with an axon and no dendrites are present in **embryos**.

**Final Answer**: Unipolar neurons with an axon and no dendrite are present in **embryos**.

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