Hematopoiesis in embryo is

Options

A. Amnion
B. Chorion
C. Allantois
D. Yolk sac

Answer

### Step-by-Step Solution:

1. **Understanding Hematopoiesis**:
- Hematopoiesis refers to the process of blood cell formation. The term "poiesis" means formation, while "hematopoiesis" specifically pertains to the formation of blood cells.

2. **Identifying the Role of Extraembryonic Membranes**:
- In the context of embryonic development, hematopoiesis occurs in association with extraembryonic membranes. These membranes are crucial for various functions during the development of the embryo.

3. **Listing the Extraembryonic Membranes**:
- The main extraembryonic membranes include:
- Amnion: Provides protection to the embryo.
- Chorion: Involved in the formation of the placenta.
- Allantois: While it has a role in some species, it is non-functional in humans regarding hematopoiesis.
- Yolk Sac: This is the membrane responsible for hematopoiesis in the embryo.

4. **Identifying the Correct Answer**:
- Among the extraembryonic membranes, the yolk sac is specifically responsible for the formation of blood cells during embryonic development. Therefore, the correct answer to the question is the Yolk Sac.

### Final Answer:
Hematopoiesis in the embryo is primarily carried out by the Yolk Sac.

---