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.
This is the most crucial period of prenatal development. During the embryonic period, cells begin to take on different functions through a process called differentiation. After this, a process called gastrulation forms three layers, called germ layers.