Now, what exactly is the function of the inner cell mass and the trophy blast? Well, the trophy blast will eventually develop into the coriane and the placenta of the fetus, while the inner cell mass, these cells here, shown in light purple, will eventually develop into the actual organism, into the tissues, into the organs and the systems of that individual. Now, notice, everything we've discussed so far was actually before implantation took place. So during fertilization, the zygote begins to move. It undergoes the first mitotic division. And right about here, we form that marula, or the Morola.