The characteristic that is shared by urea. Uric acid and ammonia is/are
(A) They are nitrogenous wastes
(B) The all need very large amount of water for excretion
(C) They are all equally toxic
(D) They are produced in the kidneys

Options

A. A only
B. A and C
C. A and D
D. A, C and D

Answer

To solve the question regarding the shared characteristics of urea, uric acid, and ammonia, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding the Compounds**:
- Urea, uric acid, and ammonia are all nitrogenous wastes produced during the metabolism of proteins.

2. **Analyzing Option (A)**:
- **Statement**: They are nitrogenous wastes.
- **Evaluation**: This statement is true. All three compounds are indeed nitrogenous wastes formed from the breakdown of proteins.

3. **Analyzing Option (B)**:
- **Statement**: They all need a very large amount of water for excretion.
- **Evaluation**: This statement is false. Ammonia requires a large amount of water for excretion, while urea and uric acid require comparatively less water. Uric acid is excreted as a semi-solid, conserving water.

4. **Analyzing Option (C)**:
- **Statement**: They are all equally toxic.
- **Evaluation**: This statement is false. Ammonia is highly toxic, while urea is less toxic, and uric acid is the least toxic of the three. Thus, they are not equally toxic.

5. **Analyzing Option (D)**:
- **Statement**: They are produced in the kidneys.
- **Evaluation**: This statement is false. Urea, uric acid, and ammonia are primarily produced in the liver, not the kidneys.

6. **Conclusion**:
- The only correct statement is (A) that they are nitrogenous wastes. Therefore, the answer to the question is (A).

### Final Answer:
(A) They are nitrogenous wastes.

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