7. Cell Division - part 02 - Types of cell division - Amitosis

 


7. Cell Division - part 02 - Types of cell division - Amitosis


Types of cell division : 

  • Three kinds  of cell division are found in animal cells.  
  • They are - 
  1. Amitosis or  direct division
  2. Mitosis or indirect  division and 
  3. Meiosis or reductional division.
  • Mitosis can be performed  by haploid as well as diploid  cells but meiosis can be performed by diploid cells only. 
  • In honey bee, drones develop  from haploid unfertilized  eggs whereas  in  Marchantia, haploid spores form gametophyte by mitosis.

Amitosis :  

  • It is the simplest mode of  cell division. 
  • During amitosis, nucleus elongates and a constriction  appears somewhere  along its length.  
  • This constriction  deepens  and divides the nucleus into two daughter nuclei.  
  • This is  followed by  the division of  the cytoplasm which results in the formation of two daughter cells.  
  • This division  occurs in unicellular organisms, abnormal cells,  old cells and in foetal membrane cells.

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