all Recessive drosophila possible?

[Nelson Gee-con Chen]

Hello,
  This may seem like a dumb question, but since I'm new at biology
and genetics...Since I am trying to do a study on mutation in general, and
would like
to start with genetically identical drospophila, is it possible to have a
drosophila strain with all traits recessive, so to make them breed
identical generations every generation? What about a drosophila with all
traits homozygous dominant, which would accomplish the same effect? Thank
you very much in advance.