Unknown 1a and unknown 2a both does not seem to have a mutation at ade1 or ade2 since both of the crosses yielded white diploid colonies that grew well on MV plate and MV+adenine plate. Because of this, it is most reasonable to say that the unknown a mutants were complemented at every mutation and as a result, the resulting diploid cell behaves exactly as a wildtype mutation would. Because of this it can be reasoned that the red pigment that is present in both unknown a and unknown 2a is due to some other pigment intermediate that happens to look similar to that of AIR rather than there being a mutation in either ade1 or 2 which would result in the over accumulation of AIR. This would make sense since the cross with the known mutants would cause the resulting diploid colonies to complement, and the trait would not be able to be observed in MV and MV+adenine plates.
In the cross between the four unknown mutations, it is clear that the four mutations does not have mutations in the same gene since the diploid colonies that are the result of the cross behaves in a similar way as a wild type colony in both the YED, MV and the MV+adenine plate. However, there is no guarantee that the two mutant haploid colonies does not have the same mutation and the mutation is in a gene that is not vital in growing on YED, MV and MV+adenine plate and just could not be seen. In addition, the possibility that the two unknown alphas or two as may have the same mutation was not tested.
While there are many limitations to the experiment that was done, the fact that both positive control and negative control had result that was similar to previous experiments implies that the properties of YED and MV plate and the identity of the known mutants could be sure if the known mutants were different from what was previously used, the result of the cross between known mutants would have been different from previous experiments. In the YED plate especially, the result indicates that there are no excess adenine present that may skew with the result of the experiment since the cross between ade2 alpha and ade2a indicates that if a colony is white the reason is not at the fault of the plates but with the mutant colonies themselves. In the MV plate, the lack of known haploid cells and the ade2alpha ade2a crossing indicates under the condition of the plate, a haploid colonies and colonies that cannot produce adenine will not grow well, and if there was a mistake in the plate then the control would not turn out similar to previous experiments. However, since MV+adenine plate was not used last time, the cross of known haploid mutant cells were not useful in that plate, which is one of the limitations of the experiment.
Recent comments