Which of the following represents the correct combination without any exception?

Options

A.
B.
C.
D.

Answer

To solve the question, we need to evaluate each option provided in the question regarding the characteristics of different classes of animals. We will analyze the features mentioned for each class and determine which one represents a correct combination without any exceptions.

### Step-by-Step Solution:

1. **Evaluate Chondrichthyes**:
- **Mouth Position**: The mouth is ventral (correct).
- **Gills**: They have 5 to 7 pairs of gills (correct).
- **Skin**: They have placoid scales (correct).
- **Notochord**: The notochord is persistent (correct).
- **Conclusion**: All features listed for Chondrichthyes are correct.

2. **Evaluate Cyclostomes**:
- **Mouth**: The mouth is circular (correct).
- **Jaws**: They do not have jaws (correct).
- **Gills**: They have 6 to 15 pairs of gill slits (correct).
- **Scales and Appendages**: They do not have scales or paired fins (correct).
- **Conclusion**: The option incorrectly states that they have paired appendages and jaws, making this option wrong.

3. **Evaluate Aves**:
- **Feathers**: Body is covered with feathers (correct).
- **Skin**: The skin is moist and glandular (incorrect; it is dry and non-glandular).
- **Hind Limbs**: Hind limbs form the wings (incorrect; forelimbs form the wings).
- **Lungs**: Lungs are supplemented with air sacs (correct).
- **Conclusion**: The features listed for Aves contain incorrect statements, making this option wrong.

4. **Evaluate Mammalia**:
- **Mammary Glands**: Presence of mammary glands (correct).
- **Pinnae**: Presence of pinnae (correct, but absent in monotremes).
- **Limbs**: Two pairs of limbs are present (correct).
- **Conclusion**: The presence of pinnae is not universal in all mammals, making this option wrong.

5. **Final Conclusion**:
- The only class that has all characteristics correctly matched without any exceptions is **Chondrichthyes**. Therefore, the correct answer is option 1.

### Final Answer:
**Option 1: Chondrichthyes** is the correct combination without any exceptions.

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