how to determine the possible gametes for a genotyope? RrTt?? Please help and it would mean a lot if you knew how to find a childs blood type...

The first part of the question has to do with the
Principle of Segregation. When gametes are produced, members of a gene pair separate
into different gametes. Therefore, you must separate the genes Rr and the genes Tt when
producing the gametes. This individual is a dihybrid(heterozygous for two traits).
Therefore, you must place one member of each gene pair into a gamete. The possible
combinations of r's and t's are--RT, Rt, rT, rt. Those are the four possible gametes
this individual can produce. For the second part of the question, blood type is
inherited in the following manner. Allele A and B are co-dominant and allele 0 is
recessive to both. Possible genetic combinations include AA and A0 which produce an
individual with type A blood, BB and BO which produce an individual with type B blood,
AB which produces an individual with type AB and 00 which is the only combination that
produces an individual with the recessive type O.