A
polar body is a small
haploid cell that is formed concomitantly as an
egg cell during
oogenesis, but which generally does not have the ability to be
fertilized. When certain
diploid cells in
animals undergo
cytokinesis after
meiosis to produce
egg cells, they sometimes divide unevenly. Most of the
cytoplasm is segregated into one
daughter cell, which becomes the egg or
ovum, while the smaller
polar bodies only get a small amount of cytoplasm. They frequently die (
apoptose), or commit suicide, and disappear, but in some cases they remain and can be important in the life cycle of the organism.