Original sentence: The development of the primitive streak is taken, by such bioethicists, to signify the creation of a unique, potential human being.The primitive streak is an important concept in bioethics, where some experts have argued that experimentation with human embryos is permissible only until the primitive streak develops, generally around the fourteenth day of existence
Edited sentence: The development of the primitive streak is taken to signify the creation of a unique, potential human being.The primitive streak is an important concept in bioethics, where experts have argued that experimentation with human embryos is permissible only until the primitive streak develops, generally around the fourteenth day of existence