the number of workers who flatly deny its existence being pretty well 

 matched by those who defend it on both theoretical and observational 

 grounds. Neither molecular nor supramolecular helices necessarily imply 

 torsion, but they do suggest a rational mechanism for producing length 

 changes in the chromosome which are necessary to explain at least part 

 of the contraction phenomenon as well as being an essential adjunct to 

 either major hypothesis of coiling. 



BIBLIOGRAPHY 



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172 / CHAPTER 7 



