Mitosis and Interphase

• Mitosis is a type of cell division performed by body cells
• Mitosis makes identical cells
• DNA can be organized into condensed units called chromosomes
• Humans have 46 chromosomes
• You have to duplicate chromosomes during interphase before mitosis
• Cells spend most of their time in interphase
• 4 stages of mitosis is PMAT

  In prophase, the nucleus and chromosomes are condensing

  In metaphase, chromosomes line up in the middle of the cell

  In anaphase, the chromosomes move to opposite sides of the cell

  In telophase, nuclei are starting to surround the chromosomes on each side to create two new cells
• Cytokinesis is the final separation into two cells by splitting cytoplasm
• DNA - genetic info required for development and functioning of living organisms
• Chromatin - thin fibres of DNA in nucleus
• Chromosome - chromatin is packaged into chromosomes
• Sister chromatids - Duplicated chromosomes (split during cell division) held together by centromere
• Parent cell - original cell
• Daughter cell - new cells resulting from division 
• Mitosis occurs in somatic cells
• G1 - cellular contents excluding the chromosomes are duplicated

  interphase
• S - Each of the 46 chromosomes are duplicated by the cell
• G2 - The cell double checks for error or repairs
• Prophase - Chromatin condenses into duplicated chromosomes, Nucleus disappears and nuclear membrane disintegrates, centrioles move to poles (sides) and produce spindle fibres
• Metaphase - meta=middle, spindle fibres connect to chromatid on each side of duplicated chromosomes, chromosomes line up at the equator of the cell
• Anaphase - spindle fibres contract and shorten, centromere pulled apart, one of each sister chromatids move to opposite poles
• Telophase - Complete set of chromosomes at each pole of the cell, spindle fibres disappear, new nuclear membrane forms around each set of chromosomes, single chromatids uncoil to thin strands of chromatin 
• Cytokinesis - division of cytoplasm, two new cells created

  • Animal cells - new cell membrane pinches at the center
  • Plant cell -  cell plate forms at the equator and becomes a new cell