Home › AP Biology › Biology › DNA Structure and Function › Purines differ from pyrimidines structurally bec…
Purines differ from pyrimidines structurally because purines have:
AA single five-ring
BThree fused rings
CA fused double ring
DA single six-ring
Answer & Solution
Correct answer: C. A fused double ring
1. The two base categories differ in the size and shape of their ring systems.
2. The purines have a double ring structure with a six-membered ring fused to a five-membered ring.
3. Pyrimidines are smaller in size and have a single six-membered ring structure.
4. Pairing a large purine with a small pyrimidine is what keeps the helix a constant width.
5. Three fused rings appear in no DNA base at all.
_Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 14 'DNA Structure and Function', sections 14.1-14.6_
Related questions
A limitation of Sanger's original sequencing method is that it can read:Rosalind Franklin did not share the Nobel Prize for the DNA structure because:The phosphodiester bond of the DNA backbone joins which two carbons?How many base pairs are there in one complete turn of the DNA helix?Each base pair sits how far from the next along the helix?The two strands of a DNA double helix are antiparallel, meaning one runs 5' to 3' and the In the Hershey and Chase centrifugation, the heavier bacterial cells ended up in the:The Hershey and Chase experiment could label phage DNA specifically using radioactive phos