No- as the presentation of a wild type phenotypes shows there is at least one dominant wild type allele for each gene

Yes- The two mutations on the same allele are able to compliment each other sufficiently to produce a wild type phenotype

They are on the same allele- there is no dominant wild type allele to mask their activity

They are on separate alleles, but M2 has a far greater effect than previously thought

The presence of a double mutant exhibits the phenotype of the mutant gene

The presence of the wild type masks the phenotype of the mutant gene

A genes expression causes a change in the expression of another gene further down the pathway

If the mutation prevents the production of the final product

If the phenotype of a double mutant is different to the phenotype of either single mutant