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Example Questions
Example Question #51 : Dna And Rna Structure
What is one of the primary differences between the purines and pyrimidines of DNA?
The purines bond to the phosphates on the DNA backbone, whereas the pyrimidines bond to sugar
Purines consist of two rings, whereas pyrimidines consist of one ring
Purines have a lipid chain, whereas pyrimidines do not
Purines consist of a single ring, whereas pyrimidines consist of two rings
Purines consist of two rings, whereas pyrimidines consist of one ring
One of the primary differences between purines and pyrimidines is that purines consist of two rings, whereas the pyrimidines consist of one ring. One way to help remember the differences between purines and pyrimidines is that pyrimidines are like pyramids: sharp. Sharp things CUT (Cytosine Uracil Thymine). Note that uracil is only present in RNA, while thymine is only present in DNA. All nitrogenous bases bond to the sugar in the DNA backbone. The sugar is also connected to a phosphate group via a phosphodiester bond.
Example Question #52 : Dna And Rna Structure
Which of the following nitrogenous bases are purines?
Cytosine and adenine
Guanine and adenine
Adenine and thymine
Thymine and uracil
Thymine and guanine
Guanine and adenine
Purines are adenine and guanine, while pyrimidines are cytosine, thymine, and uracil.
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