This is not an art project, its a bad laptop. Let me elaborate.  Every 10th grader, even in Catholic high school, learns about generative and regulative development. The latter occurs at gastrulation (although that word is not introduced until college embryology). It Is enough of a break in development to confidently state that the change is profound. Until Evangelicum Vitae, even most Catholic ethicists considered gastrulation as the begining of life.  EV is wrong, by the way. It’s infallible point is that we must not kill something that might have a sould. Biology shows, however, that in generative development only the DNA of the mother, therefore her soul, controls the actions of the blastocyst. If an individual is certain of that, there is no sin in practicing birth control or stem cell research.