Which one is produc ed by mesoderm?

Options

A. Heart and notochord
B. Heart and brain
C. Spinal cord and notochord
D. Brain and notochord.

Answer

To answer the question "Which one is produced by mesoderm?", we will analyze the options provided and identify which structures are derived from the mesoderm layer during embryonic development.

### Step-by-Step Solution:

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

2. **Identifying Mesodermal Derivatives**:
- The mesoderm is responsible for forming various structures, including muscles, bones, the circulatory system, and certain organs.

3. **Analyzing the Options**:
- **Option A: Heart and Notochord**:
- The heart is derived from the mesoderm.
- The notochord, which is a rod-like structure that provides support, is also derived from the mesoderm.
- **Option B: Heart and Brain**:
- The heart is mesodermal, but the brain is derived from the ectoderm.
- **Option C: Spinal Cord and Notochord**:
- The spinal cord is derived from the ectoderm, while the notochord is mesodermal.
- **Option D: Brain and Spinal Cord**:
- Both the brain and spinal cord are derived from the ectoderm.

4. **Conclusion**:
- The only option where both structures are derived from the mesoderm is **Option A: Heart and Notochord**.

### Final Answer:
The correct answer is **Option A: Heart and Notochord**.

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