GRE Subject Test: Chemistry : Nucleic Acids

Study concepts, example questions & explanations for GRE Subject Test: Chemistry

varsity tutors app store varsity tutors android store

Example Questions

Example Question #3 : Biochemistry

Of the following groups of nitrogenous bases, which does not contain a purine?

Possible Answers:

Thymine, adenine, cytosine

Cytosine, thymine, guanine

Cytosine, thymine, uracil

Adenine, guanine, thymine

Guanine, uracil, adenine

Correct answer:

Cytosine, thymine, uracil


We can use the mnemonic "PurAG" to remember that the purines are adenine and guanine. The only choice that does not contain a purine, therefore, is "cytosine, thymine, and uracil." Remember, pyrimidines contain a single ring, while purines have two.

Learning Tools by Varsity Tutors