In a cross between two varieties of corn, gl1gl1Ws3Ws3 (egg parent) ×Gl1Gl1ws3ws3 (pollen parent), a triploid offspring was produced with the genetic constitution Gl1Gl1gl1Ws3ws3ws3. From which parent, eggor pollen, did the 2n gamete originate? What is another possible explanation for this occurrence?

In an ordinary cross, ggWW should give gW gamete and GGww should give Gw gamete and structure a diploid descendants of genotype GgWw . However, presently as the posterity is triploid with genotype GGgWww, we can see there are 2 G alleles and 2 w alleles, this recommends the dust parent GGww gave a diploid gamete.  

another conceivable reason for such fluctuation can be transformation. Duplication of qualities could have occurred in zygote delivering additional arrangement of chromosomes, which rendered the posterity triploid