In case I want to trace my ancestry what kind of DNA test do I need to do since Im female and I dont have Y-chromosome?
I suppose I could ask my brother to have a DNA test but what happens if a girl's brother isnt her biological one? Also what about the the ancestry from the mother's side of a person when there are no living male relatives of the mother?
For example, I have a friend whose father is Greek and mother is from Finland and they live in Greece. Assuming his Y-chromosome haplotype is J2 (high chance since his father is Greek), if he didnt know his biological parents and decided to do an ancestry DNA test he would never have a chance to learn that he is half from Finland and he carries finnish genes since mdna test is not that accurate, right?

If this is true, the currenct ancestry testing sounds really incomplete to me (excludes half of the genes a person is carrying) making all those lists with the haplotype frequency in each country very inaccurate and all the countries a lot less homogenous than what we see at the moment. Especially if we consider that a man was very likely to have kids with different women, also enslaved ones from asian/african countries, in the past, therefore producing male descendants, whose mothers' ancestry doesn't appear in the current DNA tests, a notable percent of the european population at the moment is very likely to carry non European genes that we can't trace and add to the lists of ethnicities in European countries (at least that's how it sounds to me).