Question

question 10 of 10
a nucleotide includes a phosphate group, a sugar, and what other component?
a. a hydrogen bond
b. a nitrogenous base
c. a nucleic acid
d. a protein

Explanation:

To solve this, we recall the structure of a nucleotide. A nucleotide is the basic building block of nucleic acids (like DNA and RNA) and is composed of three parts: a phosphate group, a pentose sugar (deoxyribose in DNA, ribose in RNA), and a nitrogenous base (adenine, guanine, cytosine, thymine in DNA; uracil instead of thymine in RNA).

• Option A: Hydrogen bonds are the bonds that hold the two strands of DNA together (between complementary nitrogenous bases) or stabilize RNA structures, but they are not a component of a single nucleotide.
• Option B: A nitrogenous base is indeed the third component of a nucleotide, along with phosphate and sugar.
• Option C: Nucleic acids (DNA and RNA) are polymers made up of many nucleotides, so a nucleic acid is not a component of a nucleotide.
• Option D: Proteins are made of amino acids and have a completely different structure and function from nucleotides, so they are not a component of a nucleotide.

Answer:

B. A nitrogenous base