meiosis

Cards (11)

  • the first meiotic division creates 2 daughter cells with 23 chromosomes each (46 chromosomes)
  • during prophase 1, chromosomes become visible as long threads and form homologous pairs, crossing over occurs. pairs move towards spindle fibres
  • during metaphase 1, chromosomes are arranged on spindle fibres across equator
  • during anaphase 1, pairs of homologous chromosomes move apart, so there are 23 chromosomes at each pole 
  • during telophase 1, chromosomes decondense and the nuclear membranes may reform
  • cytokinesis occurs and creates 2 daughter cells
  • the second meiotic division creates 4 haploid cells with 23 chromosomes each (23 chromatids)
  • in prophase 2, new spindle fibres form at each end of original and usually at right angles to original, chromosomes gradually move towards equator 
  • in metaphase 2, chromosomes arranged on new spindle and centromeres divide, each chromatid is now a separate chromosome
  • in anaphase 2, chromosomes migrate towards opposite poles
  • in telophase 2, the nuclear membrane forms