The Russian-American biochemist Phoebus Levene was the first to determine that nucleotides may contain one of four different nitrogen-containing bases. Levene believed that the nitrogen-containing bases occurred in equal amounts in DNA. What is the actual proportion of these bases?
a. DNA contains twice as much adenine and thymine as guanine and cytosine.
b. All four do actually occur in equal amounts. Levene was right.
c. DNA contains equal amounts of adenine and thymine, and equal amounts of guanine and cytosine.
d. DNA contains equal amounts of guanine and thymine, and equal amounts of adenine and cytosine.
e. DNA contains equal amounts of adenine and guanine, and equal amounts of thymine and cytosine.
Ans: c. DNA contains equal amounts of adenine and thymine, and equal amounts of guanine and cytosine.
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