Meiosis

During meiosis there are two divisions. Difference between mitosis and meiosis rely on the segregation of chromosomes, other elements are similar.

  • Prophase I – chromosomes form bivalents (4n), crossing over which is exchange of parts of chromatids between homologous chromosomes takes place

  • Metaphase I – bivalents arrange equatorially; the fibers of the spindle attach to the centomeres

  • Anaphase I – homologous chromosomes are pulled to the poles

  • Telophase I – chromosomes became partially unraveled

  • Cytokinesis I – two daughter cells, having 23 chromosomes (2n) originate

  • Interkinesis – it is similar to interphase but there is no duplication of DNA

  • Prophase II – chromosomes become more compact

  • Metaphase II – chromosomes arrange equatorially

  • Anaphase II – chromosomes are pulled to the poles

  • Telophase II – decondensation of chromosomes into chromatin takes place

  • Cytokinesis II – two daughter cells having 23 chromosomes (n) originate

 

 

Genes are on chromosomes. The behavior of chromosomes during meiosis explains the mechanism of heredity.

Only chromosomes are segregated in such a specific way, all other cell components simply flow with the cytoplasm into the two daughter cells. This causes differences in heredity of features determined by information from the nucleus and from other structures (for example mitochondria).

 

©  team C003548, made for ThinkQuest 2000