Multiple Choice
In the DNA double helix, which two molecules form the repeating sugar-phosphate backbone of each strand?
7. DNA and Chromosome Structure
DNA Structure
Multiple Choice
In double-stranded DNA, adenine (A) base-pairs with which nitrogenous base?
A
Guanine (G)
B
Cytosine (C)
C
Thymine (T)
D
Uracil (U)
Verified step by step guidance1
Recall the base-pairing rules in double-stranded DNA, which are governed by complementary hydrogen bonding between nitrogenous bases.
Identify that adenine (A) is a purine, and in DNA, purines pair specifically with pyrimidines to maintain a uniform structure.
Remember that in DNA, adenine (A) pairs with thymine (T) through two hydrogen bonds.
Note that guanine (G) pairs with cytosine (C), and uracil (U) is found only in RNA, replacing thymine.
Therefore, adenine (A) base-pairs with thymine (T) in double-stranded DNA.
Related Videos
Related Practice
