Both ectoderm and mesoderm contribute in the development of

Options

A. thyroid
B. adrenal
C. pancreas
D. None of these

Answer

To answer the question regarding which structures are developed from both ectoderm and mesoderm, we can follow these steps:

### Step 1: Understand the Germ Layers
The three primary germ layers formed during gastrulation are ectoderm, mesoderm, and endoderm. Each of these layers gives rise to different tissues and organs in the body.

### Step 2: Identify the Contributions of Each Germ Layer
- **Ectoderm**: This layer primarily develops into the nervous system (including the brain and spinal cord), skin, and associated structures like hair and nails.
- **Mesoderm**: This layer forms muscles, bones, the circulatory system, and various internal organs, including the kidneys and adrenal glands.
- **Endoderm**: This layer gives rise to the lining of the digestive tract, respiratory tract, and organs such as the thyroid gland and pancreas.

### Step 3: Analyze the Options Given
The question presents the options: thyroid, adrenal, pancreas, or none of these. We need to determine which of these structures is developed from both ectoderm and mesoderm.

- **Thyroid**: Originates from the endoderm.
- **Pancreas**: Also originates from the endoderm.
- **Adrenal Gland**: This gland has components that arise from both the ectoderm (the adrenal medulla) and mesoderm (the adrenal cortex).

### Step 4: Conclusion
Based on the contributions of the germ layers, the adrenal gland is the structure that develops from both ectoderm and mesoderm.

### Final Answer
Both ectoderm and mesoderm contribute to the development of the **adrenal gland**.

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