Nuclear Cytology in Relation to Development

activity adult amount amplification analysis angiosperms animals apex apical associated body cells changes chimeras chromatin chromosome chromosome number cistrons complete component condition contains cultured cycle cytoplasm D'Amato demonstrated derived differentiation diploid distribution divide division DNA content DNA synthesis Drosophila early embryo embryo sac endoreduplication et al evidence experiments female fertilization formation four frequency function fusion gametophyte genes genetic genome gland growth haploid heterochromatin histone hybridization increase individuals induced initial labeled later layers liver male mechanism meiosis meiotic meristems mitosis mitotic mosaics mutation normal nuclear nuclei nucleolus observed obtained occurs oocytes organisms origin pairing phase plants pollen polytene chromosomes population present produced proteins quiescent center rDNA recent reduced references regeneration regions replication result root rRNA satellite seed sequences shoot shown single somatic species spindle spores stage structure studied Table tetraploid tissues types undergo vitro