The nervous system is derived from :

Options

A. Ectoderm
B. Endoderm
C. Mesoderm
D. Ecto and Mesoderm

Answer

**Step-by-Step Solution:**

1. **Understanding Germ Layers**: The human body is developed from three primary germ layers: ectoderm, mesoderm, and endoderm. Each layer gives rise to different tissues and organs in the body.

2. **Identifying the Ectoderm**: The ectoderm is the outermost layer. It is responsible for forming structures such as the epidermis (skin) and the nervous system, including the brain and spinal cord.

3. **Identifying the Mesoderm**: The mesoderm is the middle layer. It contributes to the formation of bones, muscles, the heart, the circulatory system, and reproductive organs.

4. **Identifying the Endoderm**: The endoderm is the innermost layer. It primarily forms the inner lining of organs, including the liver and pancreas.

5. **Linking Nervous System to Ectoderm**: Since the nervous system is formed from the ectoderm, we conclude that the nervous system is derived from this outer layer.

6. **Final Answer**: Therefore, the nervous system is derived from the ectoderm.

**Conclusion**: The correct answer is **Ectoderm**.

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