Select the corect combinations is respect of characterstics of cartilaginous and bony fishes .
`{:("Character","Chondrichthyes","Osteichthyes"),((i)"Habitat","Freshwater","Marine"),((ii)"Scales","Placoid scales","Cyloid/Ctenoid"), ((iii)"Mouth","Suking mouth","Ventral mouth"),((iv)"Gills","4 pairs","5-7 pairs"):}`

Options

A. A)(i) and (ii)
B. B)(ii) and (iii)
C. C)(iii) and (iv)
D. D)(i) and (iv)

Answer

To solve the question regarding the characteristics of cartilaginous (Chondrichthyes) and bony fishes (Osteichthyes), we will analyze each of the four combinations provided.

### Step-by-Step Solution:

1. **Combination (i): Habitat**
- Chondrichthyes (cartilaginous fishes) are primarily marine.
- Osteichthyes (bony fishes) can be found in both freshwater and marine environments.
- **Conclusion**: This combination is **incorrect** because it states that Chondrichthyes are found in freshwater, which is not true.

2. **Combination (ii): Scales**
- Chondrichthyes have placoid scales.
- Osteichthyes have cycloid or ctenoid scales.
- **Conclusion**: This combination is **correct**.

3. **Combination (iii): Mouth**
- Chondrichthyes typically have a ventral mouth (located on the underside).
- Osteichthyes can have a variety of mouth types, but many have a terminal or sub-terminal mouth, not specifically a "sucking mouth."
- **Conclusion**: This combination is **incorrect** as it misrepresents the mouth structure of Chondrichthyes.

4. **Combination (iv): Gills**
- Chondrichthyes have 5 to 7 pairs of gills.
- Osteichthyes generally have 4 pairs of gills.
- **Conclusion**: This combination is **incorrect** because it states the opposite.

### Final Conclusion:
After analyzing all combinations, the correct characteristics are:
- Combination (ii) is correct.
- Combination (iii) is incorrect.
- Combination (i) and (iv) are also incorrect.

Thus, the correct answer is **Option B**, which states that combinations (ii) and (iii) are correct.