Placenta in human beings is formed by :

Options

A. amnion
B. chorion
C. allantois
D. chorion and allantois

Explanation

**Step-by-Step Solution:**

1. **Understanding the Placenta**: The placenta is an essential organ that develops in the uterus during pregnancy. It plays a crucial role in providing nutrients, facilitating gas exchange, and removing waste products for the developing fetus.

2. **Components of the Placenta**: The placenta is formed from three main components:
- **Chorion**: This is the outermost layer that contributes significantly to the structure of the placenta.
- **Allantois**: This structure is involved in the formation of blood vessels within the placenta and plays a role in waste management.
- **Uterine Wall**: The maternal side of the placenta is formed from the uterine wall, which interacts with the chorion and allantois.

3. **Role of Other Structures**: While the amnion is important for protecting the fetus by containing amniotic fluid, it does not contribute to the formation of the placenta itself.

4. **Conclusion**: Based on the components involved in the formation of the placenta, the correct answer to the question is that the placenta in human beings is formed by the chorion and allantois.

5. **Final Answer**: The placenta in human beings is formed by **chorion and allantois** (Option D).

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