Synaptonemal complexes begin to form during the leptoptene part of this phase, causing chiasmata to become visible.
The end of this phase is marked by terminalization of chiasmata. In animal cells, asters appear during this phase and bind to the chromatids. Human oocytes remain frozen in the fourth part of this phase until they are released during a monthly ovulation. Synaptonemal complexes begin to form during the leptoptene part of this phase, causing chiasmata to become visible. Towards the very end of this phase, centrosomes migrate to opposite ends of the cell. In this phase, chromatin condenses into chromosomes, and crossing over occurs. For 10 points, name this stage of meiosis I that follows the G2 checkpoint and precedes metaphase I.
The end of this phase is marked by terminalization of chiasmata.
prophase I [do not accept "prophase II"; do not prompt on or accept "meiosis" or "mitosis"]