Does a chicken egg embryo contain blood?

Here's why:

* Developing Circulatory System: The embryo within a chicken egg begins to develop its own circulatory system very early in its development. This system includes blood vessels and a heart that starts beating around day 3 of incubation.

* Blood Formation: The embryo produces blood cells within its yolk sac, which is the primary source of nutrients for the developing chick.

* Function of Blood: Blood carries oxygen, nutrients, and other essential substances throughout the embryo, and also removes waste products.

So, while the blood in an egg embryo is different from that of a hatched chick (it's less complex and has different types of blood cells), it is definitely present and crucial for the embryo's growth and development.