A structure, absent in pisces, has evolved in amphibians

Options

A. tail
B. Teeth
C. scales
D. internal nares.

Answer

To solve the question regarding the structure that is absent in Pisces (fishes) but has evolved in amphibians, we can follow these steps:

### Step 1: Understand the Question
The question asks for a specific structure that is not found in fish (Pisces) but is present in amphibians.

### Step 2: Analyze the Options
The options provided are:
- Tail
- Teeth
- Scales
- Internal nails

### Step 3: Evaluate Each Option
1. **Tail**: Both fishes and amphibians have tails. Therefore, this option is not correct.
2. **Teeth**: Fishes have teeth, although they may differ in structure from those of amphibians. Thus, this option is also incorrect.
3. **Scales**: Fishes are covered in scales, while amphibians typically do not have scales. However, this does not fit the criteria of being a structure that evolved in amphibians.
4. **Internal nails**: Fishes do not possess internal nails. Amphibians, particularly those that are adapted for life on land, have evolved structures like internal nails (or claws) that assist in locomotion and other functions.

### Step 4: Identify the Correct Answer
Based on the analysis, the correct answer is **internal nails**. This structure is absent in fishes and has evolved in amphibians.

### Final Answer
The structure that is absent in Pisces and has evolved in amphibians is **internal nails**.

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