Endoderm is one of three principal germinal layers of cells that are formed in early in embryonic development. Endoderm is also referred to as entoderm. The other principal germinal layers (e.g., layers of cells from which body tissues develop) are...

Mesoderm is one of three principal germinal layers of cells that are formed in early in embryonic development. Mesoderm comprises the middle germinal layer that lies between the ectodermal and endodermal layers. Mesodermal cells ultimately form...

Ectoderm is one of three principal germinal layers of cells that are formed in early in embryonic development. Ectoderm comprises the outermost germinal layer from which the nervous system, eyes, ears, epidermis, integumentary elements (glands, hair,...

Mesoderm is one of the three primary germ layers of a vertebrate embryo. A zygote is formed after fertilization which develops by cell division into a blastula. This is followed by gastrulation which is the process of cell movements and translocations...

Cell division of a fertilized egg results in the formation of a population of presumably equivalent cells. The initially large egg is cleaved into smaller embryonic cells. Cleavage is followed by gastrulation. Gastrulation is the beginning of the...

Endoderm (also called entoderm) is one of the three original layers of tissue which appear during early formation of the embryo (the embryo is the offspring, developing within an egg, seed, or the body of its mother). The three layers of embryonic...

Three layers of cells (ECTODERM, MESODERM and ENDODERM) in the developing EMBRYO that give rise to the tissues of the body; see...

A germ layer is a collection of cells, formed during animal embryogenesis. Germ layers are only really pronounced in the vertebrates. However, all animals more complex than sponges (eumetazoans and agnotozoans) produce two or three primary tissue layers...