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Multiple Choice
Which components form the backbone of a DNA molecule?
A
Alternating sugar and phosphate groups
B
Nitrogenous bases only
C
Fatty acids and glycerol
D
Amino acids
Verified step by step guidance
1
Recall the basic structure of a DNA molecule, which consists of a long chain of nucleotides.
Understand that each nucleotide is composed of three parts: a sugar molecule, a phosphate group, and a nitrogenous base.
Recognize that the backbone of the DNA molecule is formed by the sugar and phosphate groups linked together through phosphodiester bonds.
Note that the nitrogenous bases extend from this sugar-phosphate backbone and pair with complementary bases on the opposite strand, but they do not form the backbone itself.
Conclude that the correct components forming the backbone of DNA are the alternating sugar and phosphate groups.