How many of the given animals are chordates with vertebra and jaws ?
Sea hare, Doliolum , Stingray, Petromyzon , Salpa, Ichthyophis , Macropus, Clarias , Branchiostoma ,chelone, Balanoglossus

Options

A. Five
B. Six
C. Seven
D. Eight

Answer

To determine how many of the given animals are chordates with vertebrae and jaws, we will analyze each animal mentioned in the question.

### Step-by-Step Solution:

1. **Sea Hare**:
- Classification: Mollusca
- Characteristics: Invertebrate, does not have vertebrae or jaws.
- Conclusion: Not a chordate.

2. **Doliolum**:
- Classification: Urochordata
- Characteristics: Lacks vertebrae and jaws.
- Conclusion: Not a chordate.

3. **Stingray**:
- Classification: Class Chondrichthyes
- Characteristics: Has vertebrae and jaws.
- Conclusion: Is a chordate.

4. **Petromyzon (Lamprey)**:
- Classification: Class Cyclostomata
- Characteristics: Jawless fish, has vertebrae.
- Conclusion: Is a chordate, but does not have jaws.

5. **Salpa**:
- Classification: Urochordata
- Characteristics: Lacks vertebrae and jaws.
- Conclusion: Not a chordate.

6. **Ichthyophis**:
- Classification: Amphibia
- Characteristics: Has vertebrae and jaws.
- Conclusion: Is a chordate.

7. **Macropus (Kangaroo)**:
- Classification: Class Mammalia
- Characteristics: Has vertebrae and jaws.
- Conclusion: Is a chordate.

8. **Clarias (Catfish)**:
- Classification: Class Actinopterygii
- Characteristics: Has vertebrae and jaws.
- Conclusion: Is a chordate.

9. **Branchiostoma (Lancelet)**:
- Classification: Cephalochordata
- Characteristics: Lacks vertebrae and jaws.
- Conclusion: Not a chordate.

10. **Chelone (Sea Turtle)**:
- Classification: Class Reptilia
- Characteristics: Has vertebrae and jaws.
- Conclusion: Is a chordate.

11. **Balanoglossus**:
- Classification: Hemichordata
- Characteristics: Lacks true vertebrae and jaws.
- Conclusion: Not a chordate.

### Summary of Findings:
- The animals that are chordates with vertebrae and jaws are:
- Stingray
- Ichthyophis
- Macropus
- Clarias
- Chelone

### Final Count:
- Total chordates with vertebrae and jaws: **5**

### Answer:
**5**

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