Cell Division 45 



of the detailed mechanisms of cell division. However it is brought 

 about, the mechanism is a beautiful example of an intricate 

 mechanism, which functions with great precision. It ensures that 

 when a cell divides into two, not only does one gene of each kind go 

 into the two daughter cells, but they also remain in the same order 

 as in the original cell.^ Nevertheless very occasionally mistakes 

 happen. A gene may get out of its correct order, or may even be 

 omitted from one of the cells or by accident be reduplicated twice. 

 Such events, as we shall see, may be of great importance in the life 

 of the organism, because they introduce modifications which may 

 sometimes be advantageous. 



^ Dr Lajtha has suggested that the dna in the chromosome exists as one 

 single continuous thread, which becomes broken into smaller pieces during 

 the processes of preparation of dna, so that the particle size of the latter, 

 when isolated, does not represent its original condition. However, this 

 view has not been proven. 



