This diagram works for most people, but not for folks with Down's Syndrome and a few other conditions. F is for father, M for mother; each of us has up to 64 great-great-great-great-grandcestors; no more than 46 of them has had even one chromosome pair reach you; even with the occasional crossing stream, there's no more than 46, and with crossing streams, could be less.
For those who don't know, this doesn't mean the other 18 (and all of their ancestors, plus half of the ancestors of the 46) are not your ancestors -- DUH! IOW, just because the chromosomes don't make it through, doesn't mean that Oetzi (for example) has no living descendants.
One of my grandmas had no daughters (that lived), hence her mtDNA died out, and for the same reason so did her mom's -- her brother was her only sibling; on her mother's side, I know only of a brother; etc etc...
ggggGrand gggGrand ggGrand gGrand Grand parents YOU
Which bracket is Gonzaga?