Question

question 16 of 25
which best describes the structure of a dna molecule?
a. two strands of dna joined by nitrogenous bases
b. one long strand of nucleic acids
c. one long strand of amino acids
d. two strands of amino acids joined by nucleic acids

Explanation:

DNA has a double - helix structure. It consists of two strands. These two strands are held together by hydrogen bonds between nitrogenous bases (adenine - thymine and cytosine - guanine). Option B is incorrect as DNA is double - stranded. Option C is wrong because DNA is made of nucleic acids (not amino acids). Option D is incorrect as the strands are of nucleic acids and joined by nitrogenous bases (not the other way around as described in the option).

Answer:

A. Two strands of DNA joined by nitrogenous bases