title: Ultrastructure of induced transitions in the chromatin organization of Drosophila polytene chromosomes.
mesh_terms: D000818:Animals; D002875:Chromosomes / Q000187:drug effects*; D004330:Drosophila; D007814:Larva; D008853:Microscopy; D008854:Microscopy, Electron; D012469:Salivary Glands / Q000166:cytology; D012972:Sodium Hydroxide / Q000494:pharmacology*; D014508:Urea / Q000494:pharmacology*
chemical_list: D012972:Sodium Hydroxide; D014508:Urea