Vertebrate brain differentiates from

Options

A. (a) endoderm
B. (b) mesoderm
C. (c) ectoderm
D. (d) blastoderm

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks from which layer the vertebrate brain differentiates.

2. **Identifying Key Terms**: The key terms here are "vertebrate brain" and "differentiate". Differentiation refers to the process by which cells become specialized in structure and function.

3. **Reviewing Developmental Stages**:
- After fertilization, the zygote undergoes cleavage to form a blastula.
- The blastula then undergoes a process called gastrulation, leading to the formation of the gastrula.

4. **Germ Layers Formation**: During gastrulation, three primary germ layers are formed:
- **Ectoderm**: The outer layer.
- **Mesoderm**: The middle layer.
- **Endoderm**: The inner layer.

5. **Functions of Germ Layers**:
- The **ectoderm** gives rise to the nervous system (including the brain) and epidermis (skin).
- The **mesoderm** forms muscles, connective tissues, and other structures.
- The **endoderm** develops into internal organs and the digestive tract.

6. **Identifying the Correct Layer**: Since the vertebrate brain is part of the nervous system, it is derived from the ectoderm.

7. **Conclusion**: Therefore, the vertebrate brain differentiates from the ectoderm.

### Final Answer:
The vertebrate brain differentiates from the **ectoderm**.

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