·
Let's continue the process of meiosis II in the IB Biology curriculum!
Meiosis II
It involves the separation of the sister chromatids and looks very like mitosis. There are four highlights in this stage under the IB Biology.
- The nuclear membrane breaks down if present.
- Spindles reform ( shown here in the vertical plane only to distinguish from the diagrams above).
- Centrioles begin the organisation of the spindle microtubules.
- Pairs of sister chromatids will attach one to each spindle microtubule set
- All Pairs of sister chromatids aligned on the equatorial plate of the cell.
- The spindle fibres contract and the pairs of sister chromatids separate.
- Each pole receives one of the chromosomes ( one chromatid).
- Nuclear membranes form around each of the tetrad of haploid game cells.
- Notice that each cell contains two chromosomes n=2 (haploid).
- Notice that the homologous pairs are separated (no red with blue, no purple with green)
- There are some unusual chromosomes with exchanged genetic material due to cross-over.
End of this topic!
Drafted by Gina (Biology)