Which one of the following pair of waste substances is removed from blood in ornithine cycle
(a) `CO_(2)` and urea
(b) Ammonia and urea
(c) `CO_(2)` and ammonia
(d) Urea and sodium

Options

A. `CO_(2)` and urea
B. Ammonia and urea
C. `CO_(2)` and ammonia
D. Urea and sodium sail

Answer

To solve the question regarding which pair of waste substances is removed from blood in the ornithine cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Ornithine Cycle**: The ornithine cycle, also known as the urea cycle, is a series of biochemical reactions that occur primarily in the liver. Its main function is to convert ammonia, which is toxic, into urea, which is less toxic and can be excreted from the body.

2. **Identify the Waste Products**: The primary waste products produced in the ornithine cycle are urea and carbon dioxide (CO₂). Ammonia is converted into urea during this cycle, and CO₂ is released as a byproduct.

3. **Analyze the Options**:
- (a) CO₂ and urea: This option includes both substances that are indeed produced and removed in the ornithine cycle.
- (b) Ammonia and urea: Ammonia is a substrate that is converted into urea, not a product that is removed.
- (c) CO₂ and ammonia: Ammonia is not removed; it is converted into urea.
- (d) Urea and sodium: Sodium is not a waste product of the ornithine cycle.

4. **Select the Correct Answer**: Based on the analysis, the correct pair of waste substances removed from blood in the ornithine cycle is **(a) CO₂ and urea**.

### Final Answer:
The correct answer is (a) CO₂ and urea.

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