Lens and retina of vertebrate eye develop from

Options

A. mesoderm
B. ectoderm
C. endoderm
D. partly from endoderm and partly from endoderm

Answer

To determine the developmental origin of the lens and retina of the vertebrate eye, we can analyze the germ layers involved in embryonic development. Here’s a step-by-step solution:

### Step 1: Identify the Germ Layers
The three primary germ layers in vertebrate embryonic development are:
- Ectoderm
- Mesoderm
- Endoderm

### Step 2: Understand the Functions of Each Germ Layer
- **Ectoderm**: This outer layer gives rise to structures such as the skin, hair, nails, and the nervous system, including sensory organs.
- **Mesoderm**: This middle layer develops into muscles, bones, blood vessels, and other internal structures.
- **Endoderm**: This innermost layer forms the lining of the digestive tract and associated organs.

### Step 3: Analyze the Options
1. **Mesoderm**: Incorrect, as it primarily forms muscles, bones, and blood vessels.
2. **Ectoderm**: Correct, since the lens and retina are derived from this outer layer.
3. **Endoderm**: Incorrect, as it forms internal organs and does not contribute to the eye structures.
4. **Partially from Endoderm and partially from Mesoderm**: Incorrect, as both options do not contribute to the formation of the lens and retina.

### Step 4: Conclusion
The lens and retina of the vertebrate eye develop from the **ectoderm**.

### Final Answer
The correct answer is **Ectoderm** (Option 2).

---