Jaw bones are formed from

Options

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

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the embryonic layer responsible for the formation of jaw bones.

2. **Identifying the Three Germ Layers**: In embryonic development, there are three primary germ layers: ectoderm, mesoderm, and endoderm. Each layer has specific roles in forming different structures in the body.

3. **Role of Each Germ Layer**:
- **Ectoderm**: This layer is primarily responsible for forming the outer structures of the body, including the skin and nervous system. It is also involved in the formation of tooth enamel.
- **Mesoderm**: This layer is crucial for the development of bones, muscles, and connective tissues. It is responsible for forming the jaw bones.
- **Endoderm**: This layer forms the inner linings of organs, such as the digestive tract and respiratory system. It is responsible for structures like the lining of the tongue.

4. **Conclusion**: Since the jaw bones are part of the skeletal system, they are formed from the mesoderm. Therefore, the correct answer to the question is the mesoderm.

**Final Answer**: Jaw bones are formed from the mesoderm.

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