1. Sister Chromatids Separate: The centromere of each chromosome splits, separating the sister chromatids. These sister chromatids are now considered individual chromosomes.
2. Movement Towards Poles: The separated chromosomes are pulled apart by spindle fibers. The spindle fibers, made of microtubules, attach to the centromeres and shorten, pulling the chromosomes towards opposite poles of the cell.
3. Cell Elongation: As the chromosomes migrate towards the poles, the cell itself elongates, pushing the poles further apart. This ensures that the chromosomes are adequately separated and will end up in distinct daughter cells.
Key Points:
* Anaphase is a crucial stage in mitosis and meiosis because it ensures that each daughter cell receives a complete set of chromosomes.
* The separation of sister chromatids is essential for the creation of new, independent chromosomes.
* The movement of chromosomes is powered by the dynamic shortening of the spindle fibers.
Visualizing Anaphase: Imagine a tug-of-war where each chromosome is pulled by two opposing teams of spindle fibers. The teams are strong enough to break the link between the sister chromatids (the centromere), and then pull the chromosomes towards their respective poles. This is what happens during anaphase.
