The sperm cell has primarily adapted to its intended function through a variety of anatomical changes. One of the most crucial adaptations that sperm have evolved is their flagella, which propel them as they travel toward unfertilized ova. According to “Molecular Biology of the Cell,” sperm have also lost a number of organelles because such organelles are not necessary for their functioning.
Sperm cells have a very different shape than skin cells, smooth muscle cells or any of the other common cells found in the human body. Sperm are tadpole-shaped, and they carry genetic information in their rounded heads. Additionally, the heads are coated in an enzyme that allows the sperm to penetrate unfertilized ova. To provide the power necessary for their job, the middle segment of sperm cells contains an abundance of mitochondria, according to the BBC. Mitochondria are organelles that produce adenosine triphosphate, the energy currency of cells.
Sperm have a very narrow function relative to some other cells that changes their needs. For example, “Molecular Biology of the Cell” explains that sperm cells do not have a Golgi apparatus or endoplasmic reticulum, as neither is necessary for transferring the DNA contained within their heads. Additionally, sperm cells lack ribosomes, as they have no need to manufacture proteins.