Which one of the following options gives the correct categorisation of stages meiosis – I.  Zygotene Pachytene Diplotene(1) DNA–Replication Synapsis Crossing over(2) Bivalent formation Enzyme Recombinase Chiasmata visible(3) Terminalisation Desynapsis Gene-Exchange(4) Recombinase Stern Hotta Morgan on Drosophila1234

The correct categorization of stages in meiosis I is as follows:

1. Zygotene: This stage involves the alignment of homologous chromosomes.
2. Pachytene: During this stage, DNA replication occurs, and synapsis takes place, where homologous chromosomes pair up.
3. Diplotene: In this stage, crossing over occurs, leading to the exchange of genetic material between homologous chromosomes. Chiasmata, which are visible structures formed by the crossing over, become visible.
4. Terminalization: This stage involves the separation of homologous chromosomes and the completion of crossing over.
5. Desynapsis: During this stage, the paired homologous chromosomes start to separate.
6. Gene-Exchange: This stage involves the exchange of genetic material between non-sister chromatids.
7. Recombinase: Enzymes called recombinases play a crucial role in facilitating the exchange of genetic material during crossing over.
8. Stern Hotta: This term is not related to the categorization of stages in meiosis I.
9. Morgan on Drosophila: This term is also not related to the categorization of stages in meiosis I.

Therefore, the correct categorization of stages in meiosis I is 1-2-3-4.