Multiple Choice
In the DNA double helix, the two antiparallel strands are held together primarily by which type of interaction?
7. DNA and Chromosome Structure
DNA Structure
Multiple Choice
Which nitrogenous base is not found in DNA?
A
Adenine
B
Cytosine
C
Guanine
D
Uracil
Verified step by step guidance1
Recall the four nitrogenous bases found in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G).
Understand that DNA uses thymine (T) as one of its bases, not uracil (U).
Recognize that uracil (U) is a nitrogenous base found only in RNA, replacing thymine in RNA molecules.
Compare the given options to identify which base is exclusive to RNA and absent in DNA.
Conclude that uracil is the nitrogenous base not found in DNA.
Related Videos
Related Practice
