Polar bodies are the small cells that are produced during the formation of eggs in a process called oogenesis. When an egg cell undergoes meiosis, it divides unevenly, creating one large ovum (the egg) and one or more smaller polar bodies. The primary reason polar bodies cannot be fertilized is that they are generally not viable for further development.
Polar bodies are formed to discard the extra set of chromosomes that the egg has after meiosis. They contain little more than a nucleus and some cytoplasm, lacking the necessary cellular machinery and resources required to support embryo development. In essence, they are a way for the egg to ensure it retains the necessary components for successful fertilization and subsequent development.
Furthermore, polar bodies do not have the capacity for fertilization because they typically do not have the cellular structures, such as specific receptors or sufficient cytoplasmic content, needed to interact with and fuse with sperm. Therefore, while polar bodies are a natural part of the egg’s maturation process, they are not capable of contributing to reproduction.