RI – Similarity and Difference between Mitosis and Meiosis

RP2021 Raffles Institution Raffles Programme Year Four Biology Name: _______________________ ( ) Class: _____ Date: ________ Unit 8: Cell Division Similarities & Differences (A) SIMILARITIES The main similarities between mitosis and meiosis involve the mechanisms by which the chromosomes and other cell organelles replicate and are maneuvered within the cell prior to and during cell division. The mechanisms of the processes of nuclear and cytoplasmic division in mitosis and meiosis are also similar. (B) DIFFERENCES Differences between mitosis and meiosis I MITOSIS MEIOSIS I Prophase • Homologous chromosomes remain separate • No formation of chiasmata • No crossing over • Homologous chromosomes pair up • CHIASMATA form • CROSSING OVER may occur Metaphase • Pairs of CHROMATIDS line up on the equator of the spindle • Pairs of CHROMOSOMES line up on the equator of the spindle Anaphase • CENTROMERES divide • CHROMATIDS separate • Separating chromatids are genetically identical • Centromeres do not divide • CHROMOSOMES separate. The chromosomes that separate consist of two chromatids. • Separating chromosomes and their chromatids may not be genetically identical due to crossing over Telophase • SAME NUMBER of chromosomes present in daughter cells as parent cells • Both homologous chromosomes present in daughter cells if diploid • HALF THE NUMBER of chromosomes present in daughter cells • Only one of each pair of homologous chromosomes present in daughter cells Occurrence • May occur in haploid, diploid or polyploid cells • Occurs during the formation of somatic cells and some spores. Also occurs during the formation of gametes in plants • Only occurs in diploid or polyploid cells • Occurs during FORMATION OF GAMETES or spores