Yet that zygote somehow knows to divide and somehow knows to form the different types of cells that exist within our adult human body. So the question we're going to address in this lecture is how exactly does an unspecialized cell know to begin a certain set of processes that eventually allows it to form a special type of cell? So how does an unspecialized cell know, for example, to form a muscle cell and not a nerve cell? So these are the questions we're going to address in this lecture. So let's begin with the zygote stage. So when we form the zygote, the next step that happens is mitosis and the zygote begins to divide.