Primitive gut or archenteron is lined by

Options

A. Ectoderm
B. Mesoderm
C. Endoderm
D. Trophoectoderm.

Answer

To determine what lines the primitive gut or archenteron, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Primitive Gut (Archenteron)**:
- The primitive gut, also known as the archenteron, is an early structure formed during the development of an embryo. It is the precursor to the digestive tract.

2. **Identify the Germ Layers**:
- During embryonic development, the inner cell mass of the blastocyst differentiates into three primary germ layers: ectoderm, mesoderm, and endoderm.

3. **Locate the Position of the Archenteron**:
- The archenteron forms as a cavity within the developing embryo. It is specifically located in the area that will eventually become the digestive system.

4. **Determine Which Germ Layer Lines the Archenteron**:
- The archenteron is lined by the endoderm. The endoderm is the innermost layer of the germ layers and is responsible for forming the lining of the gut and other internal organs.

5. **Conclusion**:
- Therefore, the primitive gut or archenteron is lined by the endoderm.

### Final Answer:
The primitive gut or archenteron is lined by **C. endoderm**.

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