How does embryonic respiration differ in chick and human embryo?

In chick embryos, respiration occurs through the chorioallantoic membrane, which facilitates gas exchange directly with the environment, as they develop in an egg. In contrast, human embryos rely on maternal blood for oxygen and nutrient supply through the placenta, as they develop internally. This difference reflects their distinct developmental environments and strategies for meeting respiratory needs. While both systems are efficient for their respective stages, the chick embryo is more reliant on external gas exchange, whereas the human embryo depends on maternal circulation.