the process of cell division that results in gametes is known as meiosis sometimes known as reduction division we refer to gamet as sex cells such as sperm in men and egg in women meiosis is divided into the meiosis one stage and the meiosis 2 stage of cell division there are four phases in meiosis 1 prophase 1 metaphase 1 anaphase 1 and telophase 1 additionally there are four phases in meiosis 2 prophase 2 metaphase 2 anaphase 2 anaphase 2 meiosis 1 now let's focus on the first stage of meiosis known as meiosis 1 prophase 1 commences
with a diploid cell its chromatin contains two sets of chromosomes one inherited from each parent during this phase the DNA and the chromatin replicates and condenses into recognizable x-shaped chromosomes and its identical sister chromites of each chromosome the chromosomes couple up with their corresponding counterparts in a fascinating process called synapsis generating a tetrad made up of four sister chromites the true magic now begins with crossing over segments of alal swap across chromatids during this genetic exchange event creating brand new Gene combinations as meiosis 1 progress the nuclear membrane vanishes and spindle fibers emerge guiding the
movement of chromosomes metaphase 1 the moment of alignment where homologous chromosomes line up at the cells equator then comes anaphase 1 and the spindle fibers diligently separate the homologous chromosomes in each tetrad pulling them to opposite poles of the cell with til Phase 1 one chromosome from each homologous pair takes position at separate poles although they still remain in the form of sister chromites however each chromosome is still composed of sister chromites remember that the sister chromites of each chromosome are no longer identical due to AIC exchange and crossovers the spindle fibers then disappear and
the nuclear envelope reforms around the chromosomes finally cyto canis occurs meiosis one ends with two genetically distinct haid daughter cells each haid cell contains only one set of chromosomes consisting of paired sister chromites both cells now enter the next stage meiosis 2 however unlike meiosis 1 DNA is not replicated until meiosis 2 begins also in prophase 2 the nuclear envelope disappears and spindle fibers fan out from the two sets of paired centrioles during metaphase 2 the chromosomes in each cell align at the equator and attach to spindle fibers at either pole during anaphase 2 the
sister chromites of each chromosome separate and migrate to opposite poles once the sister chromed separate they are called chromosomes finally in Tila Phase 2 the spindal fibers disappear the nuclear membrane regenerates and both cells undergo cyto canis meiosis 2 ends with four genetically distinct haid daughter cells each containing only one set of chromosomes
