Which one is not character of haemochorial placenta

Options

A. `CO_(2)` and excretory products pass from foetus to mother's body
B. `O_(2)` and nutrients from mother's boyd enter the foetus
C. Chorion villi are covered by blood sinuses of mother
D. It protects foetus from mechanical shocks.

Answer

**Step-by-Step Solution:**

1. **Understanding Hemochorial Placenta:**
- Hemochorial placenta is a type of placenta where the chorionic villi are in direct contact with the maternal blood. This means that the maternal blood bathes the chorionic villi, allowing for efficient exchange of substances.

2. **Analyzing the Options:**
- **Option A:** CO2 and waste products pass from the fetus to the mother's body.
- **Option B:** CO2 and nutrients pass from the mother's body into the fetus.
- **Option C:** Chorionic villi are covered by blood sinuses of the mother.
- **Option D:** It protects the fetus from mechanical shocks.

3. **Identifying the Characteristics:**
- In a hemochorial placenta, the exchange of gases (like CO2) and nutrients occurs between the maternal blood and the fetal blood through the chorionic villi.
- Options A, B, and C describe functions and characteristics that are indeed part of the hemochorial placenta.
- However, Option D states that it protects the fetus from mechanical shocks, which is not a characteristic of the hemochorial placenta.

4. **Conclusion:**
- The characteristic that is NOT associated with the hemochorial placenta is Option D: "It protects the fetus from mechanical shocks."

**Final Answer:**
- The correct answer is **Option D: It protects the fetus from mechanical shocks.**

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