CHAPTER 

 V 



CODING BY PURINE AND 



PYRIMIDINE MOIETIES IN ANIMALS, 



PLANTS, AND BACTERIA* 



Saul Kit, Ph.D. 



T 



INTRODUCTION 



HE transfer of genetic information in biological systems may 

 be represented by the following schematic diagram: 



Filial cells 



Parental cell 



Figure 1 



Implicit in this schematic diagram are three concepts: 1) that 

 genetic information is coded in deoxyribonucleic acids (DNA); 

 2) that the transfer of genetic information from parental to filial 

 cells involves the replication of the DNA and distribution of 

 "equal" amounts to the daughter cells; and 3) that the expression 

 of genetic potential within a cell involves the transcription of 

 information from DNA to "Informational" ribonucleic acids 



*This investigation was aided in part by grants from the American Cancer Society, 

 The Leukemia Society, Inc., and The National Cancer Institute (CY-4064, CY-4238). 



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