Can you explain the full process of meiosis 1?
Here is the answer to your question,
- Meiosis I is divided into 4 phases.
- Prophase I − longest phase and is further sub-divided into 5 phases
- Leptotene − Condensation makes chromosomes become distinct and compact.
- Zygotene − Homologous chromosomes start pairing together by a process called synapsis to form a complex structure called synaptonemal complex. Two synaptonemal complexes further form a complex called bivalent of tetrad.
- Pachytene − Longest phase of prophase I
Recombination nodules appear in this stage at the sites where crossing over has to take place between non-sister chromatids of homologous chromosomes.
- Diplotene − Synaptonemal complex dissolves and recombinants separate from each other except at crossover sites to form X-shaped structure called chiasmata.
- Diakinesis − Chiasmata terminalises and chromosomes condense. Mitotic spindle assembles and nucleolus and nuclear envelope disappear.
- Metaphase I − Bivalent chromosomes align on the equatorial plate and spindle fibres appear and attach to the homologous chromosomes.
- Anaphase I − Homologous chromosomes separate; sister chromatids remain attached at their centromeres.
- Teleophase I − Nuclear membranes and nucleolus reappear. Cytokinesis follows.
- Interkinesis − Stage between meiosis I and meiosis II
Hope this helps,
All the best !!