A polar body is ejected from the egg, transforming the diploid egg into a haploid cell with 23 single-stranded chromosomes.

“And then one of those actually gets ejected from the egg, and the name of that thing that gets ejected-- it's sort of like a little Hubble pod is how I imagine it, you know, from Star Wars or from any kind of Space Odyssey movie where some thing is ready to happen. A little Hubble pod shoots out of the ship. Well, that 23 pairs is now ejected from the egg. It's called the polar body. And that's going to degenerate. It's going to go away. And in doing so, take the egg cell, which was once diploid-- it had 23 pairs of chromosomes-- and making it haploid.”