The principal nitrogenous exretory compound in humans is syntheised

Options

A. in kidneys but eliminated mostly through liver
B. in kidneys as well as eliminated by kidneys
C. in liver and also eliminated by the same through bile
D. in the liver, but eliminated mostly through Kidneys

Answer

### Step-by-Step Solution:

1. **Identify the Principal Nitrogenous Excretory Compound**:
- In humans, the main nitrogenous waste product is urea.

2. **Understand the Synthesis of Urea**:
- Urea is synthesized through a series of biochemical reactions known as the urea cycle (also called the ornithine cycle).

3. **Location of Urea Synthesis**:
- The urea cycle occurs primarily in the liver, specifically in the mitochondrial matrix and the cytosol of liver cells.

4. **Toxicity of Ammonia**:
- Ammonia, which is a byproduct of protein metabolism, is highly toxic. The urea cycle converts ammonia and carbon dioxide into urea, which is much less toxic.

5. **Elimination of Urea**:
- Once synthesized in the liver, urea is transported to the kidneys, where it is eliminated from the body through urine.

6. **Conclusion**:
- Therefore, the correct statement is that the principal nitrogenous excretory compound in humans (urea) is synthesized in the liver and eliminated mostly through the kidneys.

### Final Answer:
The principal nitrogenous excretory compound in humans is synthesized in the liver but eliminated mostly through the kidneys.

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