It allows our cell, our sperm cell, to move within the fluid. And it also contains a head that contains the cytoplasm, the organelles such as the mitochondria and the nucleus that is shown in blue. And it also contains a specialized structure known as the acrosome, found on the tip of the head, that contains special digestive enzymes that are responsible for digesting a hole in the membrane surrounding our excel, as we'll see in just a moment. Now, if we look at our XL, the XL also contains its own nucleus that contains a haploid number of chromosomes. This is the cytoplasm of our cell and it also contains organelles that are not shown. We have the plasma membrane of the xcel shown in purple.