As I understand humans have 23 pairs of chromosomes (23 from Mum and
23 from Dad) - does that mean we need the entire DNA contained in a
particular pair? e.g. Pair one has one half from each parent but is
the DNA used on each strand in the one pair?   When mapping the DNA do
they need to map both halves of the one chromosome?
Finally do we know on a pair of DNA if the DNA used is either from the
mother or the father?