Prophase
| Strasburger (1884) originally introduced this term for the early stage of nuclear division before (Gk. pro) the chromosomes divide into two chromatids, but from about 1905, with the realization that the chromosomes are double from the beginning of nuclear division, he used the term in the now universally adopted sense of the stage of mitosis or of meiosis I or II before breakdown of the nuclear membrane.
condensation of chromosomes
longitudinal splitting of chromosomes visible
formation of spindle apparatus and fragmentation of nucleus membrane |