Which one of the following statements is INCORRECT ?

Options

A. Birds and land snails are uricotelic animals.
B. Mammals and frogs are ureotelic animals
C. Aquatic amphibians and crustaceans are ammonotelic animals.
D. Birds and reptiles are ureotelic .

Answer

To determine which statement is incorrect regarding the types of nitrogenous waste excretion in animals, we can analyze each statement provided in the question.

### Step-by-step Solution:

1. **Understanding Nitrogenous Waste Types**:
- There are three main types of nitrogenous waste excretion:
- **Ammonotelic**: Animals that excrete ammonia (e.g., aquatic animals).
- **Ureotelic**: Animals that excrete urea (e.g., mammals and some amphibians).
- **Uricotelic**: Animals that excrete uric acid (e.g., birds and reptiles).

2. **Analyzing Each Statement**:
- **Statement 1**: "Birds and land snails are uricotallic animals."
- **Analysis**: Birds are indeed uricotelic as they excrete uric acid. However, land snails are typically ureotelic. Therefore, this statement is partially incorrect.

- **Statement 2**: "Mammals and frogs are ureotallic."
- **Analysis**: This statement is correct. Mammals and frogs excrete urea, making them ureotelic.

- **Statement 3**: "Aquatic amphibians and crustaceans are ammonotallic animals."
- **Analysis**: This statement is correct. Aquatic amphibians and crustaceans excrete ammonia, thus they are ammonotelic.

- **Statement 4**: "Birds and reptiles are ureotallic."
- **Analysis**: This statement is incorrect. Birds and reptiles are uricotelic, as they excrete uric acid, not urea.

3. **Identifying the Incorrect Statement**:
- After analyzing all statements, we find that:
- Statement 1 is partially incorrect due to the classification of land snails.
- Statement 4 is incorrect as it misclassifies birds and reptiles as ureotelic.

### Conclusion:
The incorrect statement is **Statement 4**: "Birds and reptiles are ureotallic."