Besides mammals , placenta like structure also occurs in

Options

A. Platyhelminthes
B. Amphibians
C. Bony fishes
D. Cartilaginous fishes

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about organisms, besides mammals, that have a placenta-like structure. We need to identify which of the given options has such a structure.

2. **Analyzing the Options**:
- **Platyhelminths**: These are flatworms and are classified as non-chordates. They do not have a placenta-like structure. Therefore, this option is incorrect.
- **Amphibians**: Amphibians are primarily oviparous (egg-laying) and do not possess a placenta-like structure. Thus, this option is also incorrect.
- **Bony Fishes**: Like amphibians, bony fishes are generally oviparous and do not have a placenta-like structure. This option is incorrect as well.
- **Cartilaginous Fishes**: This group includes sharks and rays, which can be either oviparous or viviparous. Some species of cartilaginous fishes, such as sharks, exhibit viviparity and possess structures similar to a placenta, such as the trophonymata and yolk sac placenta.

3. **Conclusion**: Based on the analysis, the correct answer is **cartilaginous fishes**, as they have placenta-like structures that provide nourishment to the developing young.

**Final Answer**: Cartilaginous fishes.

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