For the homozygous parent for the white flower, it'd be either WW or ww, it just depends on if the genotype is homozygous dominant or homozygous recessive. As for the red parent plant it'd be the same either RR or rr, it's just depends on if it's homozygous dominant or homozygous recessive.
If mitotic cell division is the only way a particular species of a single celled organisms can reproduce it is most likely <u>that prokaryotic cell or the unicellular organism that also included the archea followed the process of mitotic division in order to survive and transmit the right amount genetic materials inside the different levels of generations.</u>
As, they were not complex in the cellular machinery which they had but rather went on for an alternative to save energy and reproduce the healthy form of there own species, having the right number of genetic material in them as well just like there parents had.