Currently almost half of the produce harvested in the united states is ruined by spoilage! if the flavr savr gene was used to reduce spoilage, how might the grocers ripen the fruit in a controlled manner once it reaches the store?

Vine with enthylene is used for ripening

Explanation:

FLAVR SAVR gene reduces spoilage in order to commercialize a crop so that it is easily transported and marketed.  

Such engineered crops fruits are ripened through external means. Unlike the old practice of using ethylene for ripening crops, these GMO fruits are ripened by using vine along with ethylene. Usage of only ethylene prevents the ripening of fruits from inside while ethylene along with vine ripens the fruit completely thereby preserving its freshness, flavor and also reduces spoilage.  

haploid cells;

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).