Mitososis

• Steps of mitosis:

  1. DNA condenses to form chromosomes.
  2. Chromosomes line up along of the centre of the cell.
  3. Cell fibres pull the 2 arms of each chromosomes to opposite sides of the cell.
  4. Cytokinesis - the entire cell divides to form 2 identical daughter cells.
• Reasons why new cells are required:

  • Growth (we need more cells to grow).
  • Development (we need new cells types as we develop new tissues).
  • Repair (we need to relace cells we lose each day).
• The cell cycle is the series of steps that take place as a cell grows then divides.
• Steps of cellular cycle:

  1. Cellular growth - cell gets larger and prodices more sub cellular structures such as mitochondria and ribosomes.
  2. DNA replication - chromosomes duplicate, so that each consist of 2 arms.
  3. More cell growth.
  4. Mitosis - the DNA divides into 2.
  5. Cytokenesis - the cell divides into 2.