Ammonia is excreted by most :

Options

A. bony fishes
B. adult amphibians
C. land snails
D. insects

Explanation

To answer the question "Ammonia is excreted by most:", we will follow these steps:

### Step 1: Understand the Types of Excretory Products
- Organisms can be classified based on the type of nitrogenous waste they excrete. The main categories are:
- **Ammonotelic organisms**: Excrete ammonia as their primary nitrogenous waste.
- **Uricotelic organisms**: Excrete uric acid.
- **Ureotelic organisms**: Excrete urea.

### Step 2: Identify Ammonotelic Organisms
- Ammonotelic organisms typically include:
- Most bony fishes
- Aquatic amphibians
- These organisms excrete ammonia directly into the water, where it can be diluted.

### Step 3: Analyze the Given Options
- The options provided are:
1. Bony fishes
2. Adult amphibians
3. Land snails
4. Insects
- Among these, we need to identify which group primarily excretes ammonia.

### Step 4: Evaluate Each Option
- **Bony fishes**: Most of them are ammonotelic and excrete ammonia.
- **Adult amphibians**: Generally, they are ureotelic, excreting urea.
- **Land snails**: They are uricotelic and excrete uric acid.
- **Insects**: They are also uricotelic and excrete uric acid.

### Step 5: Conclusion
- Based on the analysis, the correct answer is that **most bony fishes** excrete ammonia. Therefore, the answer to the question is **option A: bony fishes**.

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