Human placenta is derived from

Options

A. Ectoderm
B. Trophoblast
C. Endoderm
D. Mesoderm

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the origin of the human placenta. The placenta is a vital organ that forms during pregnancy, facilitating the exchange of nutrients and waste between the mother and the developing fetus.

2. **Identifying Relevant Structures**: The placenta is derived from extra embryonic membranes, also known as fetal membranes. These include the amnion, chorion, allantois, and yolk sac.

3. **Focusing on the Chorion**: Among these membranes, the chorion plays a significant role in the formation of the placenta. It consists of two layers:
- **Outer Layer**: Formed from trophoblast cells.
- **Inner Layer**: Formed from somatopleuric extra embryonic mesoderm.

4. **Role of Chorionic Villi**: The chorionic villi, which are projections from the chorion, are crucial for the formation of the placenta. They interact with the uterine tissue to establish the placenta.

5. **Conclusion**: Since the outer layer of the chorion is formed from trophoblast cells, and the chorionic villi are derived from this layer, we can conclude that the human placenta is derived from trophoblast cells.

6. **Final Answer**: The human placenta is derived from trophoblast cells, which are part of the chorion.