Cell theory changed the conception of embryonic development and heredity Everyone know that, before the rises of the technology, human are lack of the knowledge especially in the world of sciences. Thus, many theory came out at that time is 100 percent based on assumption only and far away from the truth. For example, 5th before century, a well-known people at that time which is Aristotle had come out with the “Preformation Theory”. The theory state that everything in the embryo was performed from the beginning and simply got bigger during development. In other words, all adult part of organism is performed in egg and development is a process which is the growth of the adult part of that particular organism that already existed. Then the world changes with the help of technology and corrected all the theories before mostly in the world of sciences. And now everyone believed that every single living organism in this world was came from a single cell and further develop to become an adult. It had been prove early in 19th century when the 2 famous scientist which is Matthias Schleiden …show more content…
After about 12 division cycles, the embryo, now known as a blastula, consist of many small cells surrounding a fluid-filled cavity (the blastocoel) above the larger yolky cells. Already, changes have occurred within the cells and they have interacted with each other so that some future tissue types-the germ layers- have become partly specified. There are three types of embryonic layers that produced during gastrulation which is endoderm, ectoderm and mesoderm. The endoderm, make the lining of the gut and associated organs like the pancreas and liver. Cells in the middle layer, the mesoderm, form pretty much everything else on our inside: muscle, bone, heart, and kidneys, and all the connective tissues in between. Those cells in the outermost layer, the ectoderm, become skin and