Eukaryotes have a nucleus with a membrane, larger ribosomal subunits, usually reproduce sexually, and may not have a cell wall. Prokaryotes have no membrane around the nucleus, smaller ribosomal subunits, reproduce asexually, and do have cell walls.
The development of offspring takes place inside the UTERUS
The fox has more so he can keep more heat in but in the summer he will get overheated. hunting with big fur is hard and other ones would have an advatange