The Theory of the Gene

14 chromosomes allelomorph appear autosomes back-crossed bivalents carried chro chromo chromosome groups chromosome number color conjugate contain cross crossing-over cytological Datura daughter develop dioecious diploid dominant double Drosophila Drosophila melanogaster egg-cells Einkorn embryo Emmer Emmer group eyeless F₁ factors fertilized flies gametophyte gemini genetic evidence germ-cells give half haplo-IV haploid haploid number haplonts hybrid individual interpretation intersexes kinds linkage male and female mated maturation division melanogaster mosomes moths mutant mutant types normal nucleus number of chromosomes Oenothera offspring organs ovary pair of chromosomes parent parthenogenetic plants polar body pole pollen grains pollen mother cells polyploid present produced protonema race ratio recessive genes relation second division secondary set of chromosomes sex-determination sex-linked shown single chromosomes species sperm sperm-cells sporophyte studied sylvestris Tabacum takes place teosinte tetraploid theory tion triploid trisomic trisomic types white eyes white-eyed wild type wings Witschi X-chromosomes