Which one develops from endoderm.

Options

A. Nervous system, urinary bladder and eye
B. Liver,connective tissue and heart
C. Thymne, spinakl cord and brain
D. Liver, pancreas and thymus/thyroid.

Answer

To determine which structures develop from the endoderm, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

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

2. **Analyze Each Option**:
- **Option A**: Nervous system, urinary bladder, eye
- Nervous system: Ectodermal origin
- Urinary bladder: Endodermal origin
- Eye: Ectodermal origin
- Conclusion: This option contains both ectodermal and endodermal structures, but not exclusively endodermal.

- **Option B**: Liver, connective tissue, heart
- Liver: Endodermal origin
- Connective tissue: Mesodermal origin
- Heart: Mesodermal origin
- Conclusion: This option also contains structures from different germ layers, not exclusively endodermal.

- **Option C**: Thymus, spinal cord, brain
- Thymus: Endodermal origin
- Spinal cord: Ectodermal origin
- Brain: Ectodermal origin
- Conclusion: This option includes both ectodermal and endodermal structures, not exclusively endodermal.

- **Option D**: Liver, pancreas, thymus, and thyroid
- Liver: Endodermal origin
- Pancreas: Endodermal origin
- Thymus: Endodermal origin
- Thyroid: Endodermal origin
- Conclusion: All structures in this option are derived from the endoderm.

3. **Final Answer**:
- The only option that exclusively contains organs that develop from the endoderm is **Option D: Liver, pancreas, thymus, and thyroid**.