What are the components of a nucleotide?

A nucleotide is the fundamental building block of nucleic acids such as DNA and RNA. It is composed of three key components: a pentose sugar, a phosphate group, and a nitrogenous base. The pentose sugar can either be ribose in RNA or deoxyribose in DNA, which is where it gets its name. The phosphate group is responsible for linking nucleotides together through phosphodiester bonds, creating the backbone of the nucleic acid strand. The nitrogenous base varies—adenine, thymine, cytosine, guanine, or uracil—providing the unique coding information necessary for the functions of DNA and RNA.

Understanding these components is crucial as they play pivotal roles in the structure and function of genetic material. This cohesive unit facilitates various biological processes, including genetic inheritance and protein synthesis. Thus, the first choice accurately captures the essential components of a nucleotide in a clear and comprehensive manner.