mitosis and the cell cycle

• What is the cell cycle?

  The regular sequence of growth and division that cells undergo
• Growth and DNA replication

  1) In a cell that's not dividing, the DNA is all spread out in long strings

  2) Before it divides, the cell has to grow and increase the amount of subcellular structures such as mitochondria and ribosomes

  3) It then duplicates its DNA- so there's one copy for each new cell. The DNA is copied and forms X- shaped chromosomes. Each 'arm' of the chromosome is an exact duplicate of the other
• What is mitosis?

  Cell division that generates new cells for growth and repair. The division of one cell into two genetically identical daughter cells
• Stages of mitosis

  1) chromosomes line up at the centre of the cell and cell fibres pull them apart, the arms go to opposite ends of the cell

  2) membranes form around each set of chromosomes - these become the nuclei

  3) cytoplasm and cell membrane divide

  4) the cell has now produced two genetically identical daughter cells
• stage one of mitosis

  DNA/chromosomes replicate

  subcellular structures increase in number
• stage two of mitosis 


  one set of chromosomes is pulled to each end of the cell
• stage three of mitosis

  the cytoplasm and cell membrane divides to form two cells