blastoderm
/ˈblastə(ʊ)dəːm
/noun Embryology
A blastula having the form of a disc of cells on top of the yolk.When the membranes surrounding the peripheral nuclei fuse to form the 6000 cells of the cellular blastoderm, they enclose 175-225 polyploid yolk nuclei within a large syncytial yolk cell....
- As a result, the blastodisc on the yolk becomes a blastoderm.
- When the egg is laid, the blastoderm contains several hundred cells.