The Illinois state sales tax rate is 6.25%, and the average IL sales tax after local surtaxes is 8.19%. Counties and cities can charge an additional local sales tax of up to 3.5%, for a maximum possible combined sales tax of 9.75%.
(clue: look up Hirschsprung's disease.) The first important step in development of the digestive system occurs during folding of the embryonic disc as neurulation takes place (weeks 4 and 5) - the thin endodermal layer is gathered up' inside the embryonic body to form a tubular structure. Gut tube, respiratory diverticulum, yolk sac, and allantois.
The Germ Layers. The Germ Layers are a group of cells, formed during embryogenesis and eventually give rise to all of our tissues and organs through the process of organogenesis. From inner to outer, the germ cell layers are the endoderm, mesoderm, and ectoderm. The division of the germ layers is especially evident during embryogenesis, when the embryo grows from a single fertilized egg into an organism ready to live on its own. Together the germ layers make up the organism.