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Mitosis

Mitosis

  • This is the division of somatic/body cells. These cells are diploid which means they have the full number of chromosomes – 46.
  • When a cell divides by mitosis it makes two cells identical to the original cell, each with a nucleus containing the same 46 chromosomes.
  • This type of cell division is for growing/replacing cells that have been damaged, or simply growth.
  • Asexual reproduction also uses mitosis, such as strawberry plants.

The process

  1. Before a cell divides, the DNA is spread out in long strings.
  2. When a cell divides, its DNA needs to be duplicated so there is one copy for each new cell. Each DNA is copied and forms an X-shaped chromosome. Each ‘arm’ of the chromosome is an exact duplicate of the other.
  3. These chromosomes line up at the equator of the cell. Spindle fibres attached to these, at either side of the cell, are pulled apart. As a result, the two arms of each chromosomes go to opposite ends of the clel.
  4. Membranes being to form around each set of chromosomes. These become the nuclei of the two ne cells.
  5. The cytoplasm divides.
  6. Two new diploid cells have been formed which are genetically identical.