Multiple Choice
Why are the two strands of DNA described as complementary to one another?
7. DNA and Chromosome Structure
DNA Structure
Multiple Choice
Which components form the backbone of the DNA molecule?
A
Nitrogenous bases and phosphate groups
B
Phosphate groups and ribose sugars
C
Alternating deoxyribose sugars and phosphate groups
D
Deoxyribose sugars and nitrogenous bases
Verified step by step guidance1
Recall the structure of a DNA molecule, which consists of a sugar-phosphate backbone and nitrogenous bases attached to the sugars.
Identify the sugar present in DNA, which is deoxyribose, a five-carbon sugar lacking one oxygen atom compared to ribose in RNA.
Understand that the backbone of DNA is formed by alternating units of deoxyribose sugars and phosphate groups connected by phosphodiester bonds.
Recognize that nitrogenous bases (adenine, thymine, cytosine, guanine) are attached to the deoxyribose sugars but do not form the backbone itself.
Conclude that the correct components forming the DNA backbone are the alternating deoxyribose sugars and phosphate groups.
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