title: Patterned disjunction in Drosophila melanogaster. I. Assortment of SPA pol - +  and X,Y in the stock N1.
mesh_terms: D003433:Crosses, Genetic; D004331:Drosophila melanogaster; D006579:Heterozygote; D008540:Meiosis; D010375:Pedigree; D012730:Sex Chromosomes; D012744:Sex Ratio