The stages of meiosis

Prophase I Diakinesis Centromere with kinetochore microtubule Mitotic spindle Prophase I: Diakinesis The meiotic spindle is well established, with bundles of kinetochore microtubules tethering homologous chromosomes of tetrads to opposite poles. The nuclear envelope is fully degraded. Tetrads are moved toward the middle of the cell. MEIOSIS I: Separates homologous chromosomes Kinetochore microtubule Metaphase plate Astral and nonkinetochore mictrotubules Metaphase l Tetrads are aligned along the metaphase plate, with each chromosome of a homolo- gous pair tethered to kineto- chore microtubules emanat- ing from centrosomes at opposite poles of the cell. The kinetochores of sister chromatids are attached to the same centrosome, and sister chromatids are joined by cohesin to prevent their premature separation. Chias— mata linking nonsister chro- matids are broken. Sister chromatids remain attached Homologous chromosomes separate Anaphase l Depolymerization of kinetochore microtubules begins the disjunction of homologous chromosomes, which start moving toward opposite poles. Sister chromatids remain joined by cohesin. Cleavage — furrow Nuclear envelope re-forms Telophase I and Cytokinesis Nuclear membranes re—form around the chromosomes clustered at each pole. Each newly formed nucleus contains a haploid set of chromosomes. Chromo- somes may partially decon- dense. Cytokinesis divides the cytoplasmic material of the cell by dividing the nuclear contents between the cells. The cytoplasmic division may be unequal.