Therefore, abortion is prima facie wrong. There is no non-arbitrary dividing line between a zygote and the person it becomes. It is prima facie wrong to kill a person. Therefore, it is prima facie wrong to kill a zygote. The fetus is a person.
Every person has a right to life.
The mother has a right to bodily autonomy, that is, the right to decide what happens in and to her body. The right to life is stronger and more stringent than the right to bodily autonomy and so outweighs it in cases of conflict. Therefore, it is wrong to kill the fetus.