Nuclear membrane is barely visible. Polar fibers, which are microtubules that make up the spindle fibers, reach from each cell pole to the cell's equator. Kinetochores , which are specialized regions in the centromeres of chromosomes, attach to a type of microtubule called kinetochore fibers. The chromosomes begin to migrate toward the cell center. Nematode Ascaris megalocephala in late Prophase.
Nuclear membrane is no longer visible.
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