Question

Describe the timeline when the ova completes:

Prophase II

Prophase I

Anaphase I

Metaphase II

Entire Meiosis process

Answer 1

Prophase II is the process where the cell starts it's secondary meiotic division in which two haploid cells eventually develops into four haploid cells. This process starts immediately after the cytokinesis. In the process of prophase II, it condenses chromatin first into chromatids, and then more tightly into chromosomes. Simultaneously, the nuclear membrane dissolves and leaves the cytoplasm in which a network of proteins has enough space to create pathways reaching from one side of the cell to the other i.e., the spindle apparatus.

Prophase I have 5 stages - leptotene, zygotene, pachytene, diplotene and diakinesis. It is the longest phase of meiosis, typically consuming 90% of the time for the two divisions. In this stage each chromosome carefully aligns with its homologue partner so that the two match up at corresponding positions along their full length.

Anaphase I starts when the two chromosomes of each bivalent separates and start moving towards the opposite poles of the cell as a result of the action of the spindle. In this stage, the sister chromatids remain attached at their centromeres and move together toward the poles.

Metaphase II is the stage where daughter cells produced by the first meiotic division and the spindle takes again the chromosomes to the metaphase plate.
Meiosis is the process which forms haploid cells are formed by the nuclear division. It is the part of cell reproduction cycle that results in identical daughter nuclei that are also genetically identical to the original parent nucleus.