meiosis I

prophase I

chromatin condenses, homologous pairs form a bivalent, nucleolus disappears, spindle forms, crossing over occurs, centrioles migrate to opposite poles, nuclear envelope breaks down

metaphase I

bivalents line up on equator of spindle, independent assortment occurs

anaphase I

homologous pairs separated as microtubules pull whole chromosomes to opposite ends of spindle

telophase I

two new nuclear envelopes form, cell divides by cytokinesis