Trachea to prevent swallowed matter from entering the trachea. In the fourth week of development of the human embryo as the respiratory bud grows, the trachea separates from the foregut through the formation of tracheoesophageal ridges which fuse to form the tracheoesophageal septum and this separates the future trachea from the oesophagus and divides the foregut tube into the laryngotracheal tube. Before the end of the fifth week, the trachea begins to develop from the laryngotracheal tube which develops from the laryngotracheal groove. The first part of the cephalic region of the tube forms the larynx, and the next part forms
What Is Life? as a highly ordered process, but which is caused by random movement of atoms or molecules. If the number of atoms is reduced, the behaviour of a system becomes more and more random. He states that life greatly depends on order and that a naïve physicist may assume that the master code of a living organism has to consist of a large number of atoms. In chapter II and III, he summarizes what was known at this time about the hereditary mechanism. Most importantly, he elaborates the important role mutations play in evolution. He concludes that the carrier of hereditary