What fertilization also does is it activates the egg, it transforms the egg into the zygote. And this begins several processes, metabolic processes, that eventually lead to and initiate embryological development, as we'll see in the next several lectures. Now, let's actually discuss and focus on the process of fertilization and how it actually takes place. So fertilization is the interaction between sperm cell and our egg cell. The sperm cell is shown in blue and the egg cell is this entire structure. So notice the sperm cell contains a tail, that is the flagellum.