Find out the wrong statement :

Options

A. Amnion is outer layer containing amniotic fluid that acts as shock absorber to soft embryo
B. Yolk sac is a foetal membrane that helps in nourishment of the embryo
C. In mammals, allantois is not excretory in function
D. Chorio-allantoic membrane develops villi and participates in development of placenta

Answer

To find out the wrong statement among the given options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Analyze the First Statement:**
- **Statement:** "Amnion is the outer layer containing the amniotic fluid that acts as the shock absorber to the soft embryo."
- **Explanation:** The amnion is indeed a membrane that surrounds the embryo and contains amniotic fluid. This fluid serves as a cushion, protecting the embryo from mechanical injury. Thus, this statement is **correct**.

2. **Analyze the Second Statement:**
- **Statement:** "Yolk sac is the fetal membrane that helps in the nourishment of the embryo."
- **Explanation:** The yolk sac is an extra-embryonic membrane that provides nutrients to the developing embryo. Therefore, this statement is also **correct**.

3. **Analyze the Third Statement:**
- **Statement:** "In mammals, allantois is not excretory in function."
- **Explanation:** The allantois is an extra-embryonic membrane that plays a crucial role in waste management and gas exchange for the developing embryo. It does have an excretory function. Hence, this statement is **incorrect**.

4. **Analyze the Fourth Statement:**
- **Statement:** "Chorioallantoic membrane develops villi and participates in the development of the placenta."
- **Explanation:** The chorioallantoic membrane does indeed develop villi that are involved in the formation of the placenta. Thus, this statement is **correct**.

### Conclusion:
The wrong statement among the options is the **third statement**, which claims that "in mammals, allantois is not excretory in function."

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