Describe the events that occur during prophase I of meiosis I. Which events are similar to those of prophase during mitosis; which events are different from mitotic prophase?
In prophase I, as in mitosis, the replication of genetic material has already occurred during the interphase just before prophase; chromosomes become visible as they thicken and shorten but do not become visibly double-stranded until late prophase; nucleoli fade from view; the nuclear membrane disappears; and the spindle is organized. Yet, unlike in mitosis, in meiosis homologous chromosomes pair up on the spindle, laying so close to each other that they often become intertwined. The pairing of homologous chromosomes is called synapsis. Each homologous pair moves toward the equator of the spindle during late prophase.
