AGB 121: Principles of Animal Genetics and Population Genetics (2+1)

METAPHASE I

Tetrads align at the metaphase plate. One homologue is pulled above the metaphase plate, the other below. The centromeres of homologous chromosomes are oriented toward the opposite cell poles. The centrioles are at opposite poles of the cell. Spindle fibers from one pole of the cell attach to one chromosome of each pair (seen as sister chromatids), and spindle fibers from the opposite pole attach to the homologous chromosome (again, seen as sister chromatids).