AP BIOLOGY

Detailed explanation-1: -Endoderm is the innermost of the three primary germ layers in the very early embryo. The other two layers are the ectoderm (outside layer) and mesoderm (middle layer). Cells migrating inward along the archenteron form the inner layer of the gastrula, which develops into the endoderm.

Detailed explanation-2: -These adult tissues are derived from three embryonic cell layers called germinal layers; the outer layer is the ectoderm, the middle layer is the mesoderm, and the innermost layer is the endoderm.

Detailed explanation-3: -The function of the embryonic endoderm is to construct the linings of two tubes within the body. The first tube, extending throughout the length of the body, is the digestive tube. Buds from this tube form the liver, gallbladder, and pancreas.

Detailed explanation-4: -The ectoderm is one of the three primary germ layers formed in early embryonic development. It is the outermost layer, and is superficial to the mesoderm (the middle layer) and endoderm (the innermost layer). It emerges and originates from the outer layer of germ cells.

Detailed explanation-5: -The epithelial tissue derived from the endoderm includes the epithelial lining of the digestive tract, except at the open ends, and the epithelial lining of all hollow structures formed as outpockets in the digestive tract. This includes: The parenchyma of the liver including communicating or connecting ducts.