When do spindle fibres attach to each sister chromatid?

During Metaphase II of meiosis, spindle fibres attach to each sister chromatid. At this stage, the chromosomes are aligned at the cell's equatorial plane, and each chromosome consists of two sister chromatids joined at the centromere. The spindle fibres, which are composed of microtubules, extend from the centrosomes and attach to the kinetochores of the sister chromatids. This attachment is crucial for the accurate segregation of chromosomes during the subsequent stages of cell division.

The spindle fibres pulling on the kinetochores ensure that each sister chromatid will be pulled towards opposite poles of the cell in Anaphase II, leading to the formation of four genetically diverse gametes at the end of meiosis. Understanding the role of spindle fibres and their attachment to chromatids is essential in comprehending how genetic material is distributed during cell division.