Question

Explain the process of meiosis - I

Answer 1

Meiosis 1 is initiated after the parental chromosomes have replicated to produce identical sister chromatids at the S phase. It includes four steps which are as follows:

• Prophase 1: It is typical and more complex than the prophase of mitosis.It has been subdivided into Leptotene, Zygotene, Pachytene, Diplotene and Diakinesis.
• Metaphase 1: Bivalent chromosomes align on the equatorial plate. Orientation of maternal and paternal chromosomes of each bivalent on this phase is random and may face any one of the pole.
• Anaphase 1: Homologous chromosomes separate and each poles receives a random assortment of maternal and paternal chromosomes. Each chromosomes still contains a pair of sister chromatids,attached together by common centromere.
• Telophase 1: The nuclear membrane and nucleolus reappear, cytokinesis follows and this is called as dyad of cells.