Cell Division

• Interphase is composed of three stage

  G1

  S

  G2
• G1 stage


  also known as Gap 1 or Growth 1, involves the doubling of organelles, such as mitochondria and ribosomes.
• S stage


  or synthesis stage, DNA replication or doubling occurs, resulting in duplicated chromosomes
• G2


  involves the production of proteins necessary for cellular division
• Gametes


  contain only half the number of chromosomes, thus the term haploid number
• Stages of Mitosis

  Interphase

  Prophase

  Metaphase

  Anaphase

  Telophase
• Mitosis mainly involves the nucleus and the cytoplasm
• prophase


  the nuclear envelope disintegrates while chromatin fibers become tightly coiled and condensed.
• Metaphase 


  the mitotic spindle, or spindle apparatus, is completely formed. (Chromosomes parade)
• anaphase


  the sister chromatids of each duplicated chromosome separate and move toward the opposite poles of the cell
• The division of cytoplasm, known as cytokinesis
• Gametogenesis


  produced through oogenesis (for the egg cell) and spermatogenesis (for the sperm cell)
• Spermatogenesis


  the process by which sperm cell production occurs; the germ cells give rise to the haploid spermatozoa.
• Oogenesis


  the process by which the female gametes, or ova, are created
• Meiosis


  type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells
• Mitosis


  the process by which a cell replicates its chromosomes and then segregates them
• prophase I of meiosis


  replicated homologous chromosomes
• homologous chromosomes


  pairs of chromosomes in a diploid organism that have similar genes, although not necessarily identical.
• crossing-over


  a cellular process that happens during meiosis when chromosomes of the same type are lined up
• tetrad


  composed of two homologous chromosomes
• How many chromosomes do Haploid have?

  23
• How many chromosomes do Diploid have?

  46
• spindles


  Fibers that help more chromosomes to end
• How many chromatids do diploid have?

  92
• Chromosomes pair

  Sypnasis
• The newly formed cells are called daughter cells
• The original cell is called a parent cell