Meiosis

Meiosis is a form of cell division in which the a cell with 46 chromosome (referred to as "diploid" gives rise to two cells with 23 chromosomes -"haploid"). Meiosis takes place only in the formation of the gametes - sperm and egg. The two stages in the development of meiosis in the egg are shown in this diagram. Further information may be shown when the mouse hovers over each image. Click images in meoisis I for further information and for detail on pronuclei.

Meiosis I      Diakinesis -The chromosome align in the centre of the cell       Metaphase I -The two sets of chromosomes are aligned on the mitotic spindle      Anaphase I - The homologues (identical pairs of chromosome) separate       Telophase - One set of chromosomes will move out of the cell as the first polar body









Meiosis II            Anaphase II - the chromatids begin to separate - this phase is initiated by the penetration of the sperm      Telophase II -The chromatids are at oposite poles - one set begins to move out as the second polar body.      Pronuclear Zygote - the two polar bodies are evident, the two 'packages of chromosmes - one from the sperm and the other from the egg are present and will shortly fuse - a stage called syngomy.Metaphase 2 - the reduction in chromosome number begins to end with 23 sets of chromosomes