Analogous structures are

Options

A. Anatomically different but performing similar functions
B. Anatomically similar but performing different functions
C. Anatomically similar and functioning similarly
D. Anatomically different and functioning differently

Answer

**Step-by-Step Solution:**

1. **Understanding Analogous Structures**: Analogous structures refer to body parts in different species that perform similar functions but have evolved independently, meaning they do not share a common ancestor.

2. **Identifying Key Characteristics**: The key characteristics of analogous structures are:
- They perform similar functions.
- They are anatomically different.
- They arise from convergent evolution, where different species adapt to similar environments or challenges.

3. **Examples of Analogous Structures**: A classic example of analogous structures is the wings of birds and the wings of insects. Both serve the function of flight but have different anatomical structures and evolutionary origins.

4. **Analyzing the Options**:
- **Option A**: Anatomically different but performing similar functions - This is correct as it describes analogous structures accurately.
- **Option B**: Anatomically similar but performing different functions - This is incorrect as it describes homologous structures, not analogous.
- **Option C**: Anatomically similar and functioning similarly - This is also incorrect, as it again refers to homologous structures.
- **Option D**: Anatomically different and functioning differently - This is incorrect as it does not describe analogous structures.

5. **Conclusion**: The correct answer to the question "Analogous structures are" is "anatomically different but performing similar functions."

**Final Answer**: Analogous structures are anatomically different but performing similar functions.

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