Question

What event in meiosis I leads to the cell becoming haploid rather than the separation of sister chromatids?

During early prophase, centrosomes migrate to opposite ends of the cell and begin to form the spindle apparatus.
During anaphase, spindle fiber shorten, pulling chromosomes to opposite sites of the cell.
All of these are important in the formation of haploid cells
Crossing over may occur during prophase once bivatents have formed.
Formation of bivalents lead to spindle fibers from opposite poles attaching to homologous chromosomes.

Answer 1

@abb0t @Compassionate

Answer 2

Again, this is more genetics and I am not a biology specialist. Sorry. But you can ask @nincompoop He is more knowledgable in this area of biology to help you out.

Answer 3

thanks anyways