What are the three components of a nucleotide?

A nucleotide is composed of three key components: a phosphate group, a sugar molecule, and a nitrogenous base. The phosphate group is what links nucleotides together to form the backbone of DNA and RNA. The sugar molecule can vary depending on whether the nucleotide is found in DNA or RNA; DNA contains deoxyribose, while RNA has ribose. The nitrogenous base is responsible for encoding genetic information, and there are five primary bases—adenine, thymine, cytosine, guanine, and uracil (which is specific to RNA).

This understanding of the structure of nucleotides is fundamental for studying nucleic acids and their role in genetics and cellular processes. The other choices do not accurately describe the components of a nucleotide, as they include incorrect elements or combinations that do not form the essential structure of nucleotides.