Which of the following statements regarding the structure of DNA is correct?
A) the two strands are parallel.
B) the two strands are held together by intrachain hydrogen bonds.
C) the two strands have complementary base pairing.
D) the hydrogen bonding that holds the helix together is always between two purines or between two pyrimidines.
E) the ratio of adenine to guanine is the same in all organisms.

Question

Quizplus · Accepted Answer

The two strands of DNA are anti-parallel and are held together by hydrogen bonds between complementary base pairs. Adenine pairs with thymine, while cytosine pairs with guanine. This is known as complementary base pairing. The ratio of adenine to guanine can vary in different organisms. Option A is incorrect as the two strands are anti-parallel. Option B is also incorrect as the hydrogen bonds are interchain, not intrachain. Option D is incorrect as hydrogen bonding can occur between a purine and pyrimidine pair. Option E is incorrect as the ratio of adenine to guanine can vary in different organisms.

Which of the Following Statements Regarding the Structure of DNA