I need to get some information to understand how this works. I have a half-brother that I plan to do a DNA test with soon to determine if we are related. Now, I know the general stuff - father passes down Y-chromosome to father and to son. Where I start to get confusion is in the DNA aspect. Males are made up of X and Y. But what I don't understand is, our DNA is different. Even twin brothers have different DNA. So how is it that they can test the Y-Chromosome in one male(myself) and see if it pairs up with another Y-Chromosome(my half-brother)? Aren't the DNA inside of those chromosomes different?
Sorry for the dumb question. Biology confuses me. Lol.
