Poultry Judging Practice Test

During incubation, what membrane forms around the embryo that lies next to the shell?

1. Chorion

2. Amnion

3. Yolk sac

4. Allantois

The correct answer is: Chorion

The correct answer is the chorion, which is significant in the development of the embryo during incubation. The chorion is a vital extra-embryonic membrane that surrounds the embryo and serves as a protective layer. It plays a crucial role in gas exchange, allowing oxygen to enter and carbon dioxide to be expelled. This is essential for the survival of the growing embryo within the confines of the eggshell. Understanding the function of the chorion helps clarify its importance in the broader context of poultry embryology. In comparison, the amnion primarily serves to encase the embryo itself in amniotic fluid, providing cushioning and protection against physical shocks, while the yolk sac is responsible for nutrient absorption, and the allantois functions primarily in waste management and gas exchange, especially toward the later stages of development. Each of these membranes has distinct roles, but the chorion specifically is the membrane that forms directly adjacent to the eggshell and is crucial for respiratory functions during incubation.