Which of the following are the three components of a nucleotide?

• A. A nitrogenous base, a ${\mathrm{pentose}}_{\mathrm{sugar}}$, and a ${\mathrm{phosphate}}_{\mathrm{group}}$
• B. A nitrogenous base, a ${\mathrm{pentose}}_{\mathrm{sugar}}$, and a ${\mathrm{sulfate}}_{\mathrm{group}}$
• C. A nitrogenous base, a ${\mathrm{hexose}}_{\mathrm{sugar}}$, and a ${\mathrm{phosphate}}_{\mathrm{group}}$
• D. A nitrogenous base, a ${\mathrm{hexose}}_{\mathrm{sugar}}$, and a ${\mathrm{sulfate}}_{\mathrm{group}}$

Answer: (A)

Verified step by step guidance

1. Identify the basic structure of a nucleotide, which is a fundamental unit of nucleic acids like DNA and RNA.
2. Understand that a nucleotide is composed of three main components: a nitrogenous base, a pentose sugar, and a phosphate group.
3. Recognize the nitrogenous bases, which can be purines (adenine and guanine) or pyrimidines (cytosine, thymine, and uracil).
4. Identify the pentose sugar, which is a five-carbon sugar. In DNA, this sugar is deoxyribose, and in RNA, it is ribose.
5. Acknowledge that the phosphate group is essential for forming the backbone of the nucleic acid structure, linking the sugars of adjacent nucleotides.