Uricotelism is found in

Options

A. Fishes and fresh water protozoans
B. Birds, reptiles and insects
C. Frogs and toads
D. Mammals and birds

Answer

**Step-by-Step Solution:**

1. **Understanding Uricotelism**:
- Uricotelism refers to the excretion of nitrogenous waste in the form of uric acid. This is a key characteristic of certain organisms that adapt to conserve water.

2. **Types of Nitrogenous Waste Excretion**:
- There are three main types of nitrogenous waste excretion:
- **Ammonotelism**: Excretion of ammonia (common in aquatic organisms).
- **Ureotelism**: Excretion of urea (common in terrestrial organisms).
- **Uricotelism**: Excretion of uric acid (common in organisms that need to conserve water).

3. **Analyzing the Options**:
- **Option 1: Fishes and Freshwater Protozoans**:
- Freshwater fishes and protozoans typically excrete ammonia, making them ammonotelic. This option is incorrect.
- **Option 2: Birds, Reptiles, and Insects**:
- All these groups excrete uric acid, categorizing them as uricotelic. This option is correct.
- **Option 3: Frogs and Toads**:
- Frogs and toads can excrete ammonia when in water and uric acid when on land, making them not strictly uricotelic. This option is incorrect.
- **Option 4: Mammals and Birds**:
- Mammals primarily excrete urea (ureotelic), while birds excrete uric acid (uricotelic). This option is incorrect.

4. **Conclusion**:
- After analyzing all options, the correct answer is **Option 2: Birds, Reptiles, and Insects**, as they all exhibit uricotelism.