What is a nucleotide?

A nucleotide is indeed a building block of DNA and RNA, but in this context, the correct aspect of the nucleotide defined is specific to DNA. A nucleotide is composed of three parts: a sugar molecule (deoxyribose in DNA), a phosphate group, and a nitrogenous base (which can be adenine, thymine, cytosine, or guanine in DNA). Each of these components plays a crucial role in forming the structure of DNA, where the sequence of nucleotides encodes genetic information.

This definition highlights the importance of nucleotides in the formation of nucleic acids, which are essential for storing and transmitting genetic information in living organisms. By understanding this structure, one can better comprehend how genetic codes are formed and ultimately how traits are inherited.