Early cell division is to some extent independent of the number of chromosomes in the embryo, so an embryo with an abnormal number of chromosomes can look just like any other. (pacificfertilitycenter.com)
For years scientists thought that early cells use a common plan to build an animal from top to bottom. (sciencemag.org)
Do you have a collection of early cell phones, or a collection of TRS - 80 computers? (effectivecoverage.com)