Multiple Choice
In the DNA double helix, what are the “sides” of the ladder (the sugar-phosphate backbone) made of?
7. DNA and Chromosome Structure
DNA Structure
Multiple Choice
In DNA structure, which two components form the sugar-phosphate backbone of a DNA strand?
A
Nitrogenous bases and phosphate groups
B
Deoxyribose sugar and nitrogenous bases
C
Ribose sugar and phosphate groups
D
Deoxyribose sugar and phosphate groups
Verified step by step guidance1
Understand the structure of a DNA strand, which consists of a backbone and attached nitrogenous bases.
Recall that the backbone of DNA is made up of repeating units that alternate between sugar molecules and phosphate groups.
Identify the sugar in DNA as deoxyribose, which differs from ribose by lacking one oxygen atom.
Recognize that the nitrogenous bases (adenine, thymine, cytosine, guanine) are attached to the sugar molecules but do not form the backbone.
Conclude that the sugar-phosphate backbone is formed by the deoxyribose sugar and phosphate groups linked together through phosphodiester bonds.
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