Biology · Ch 7 — Cell Division
Metaphase I
Metaphase I
In metaphase-I, the spindle fibres become fully developed, and the tetrads (paired homologous chromosomes) move to the equator of the cell. They orient themselves in a specific way: the centromeres of each homologous pair face toward their respective poles, while the chromosome arms point toward the equator. Because of the growing repulsive forces between the paired homologous chromosomes, by this stage the pair is essentiall …
What this figure shows. A cell in which each pair of homologous chromosomes (a tetrad) has moved to the equator and oriented itself so that the centromere of each homologue faces its own pole while the chromosome arms — including the segments that were exchanged during crossing-over — point toward the equator, with fully formed spindle fibre …