What are the primary components of DNA?

The primary components of DNA are the nitrogenous bases adenine, thymine, cytosine, and guanine. These four bases are crucial to the structure and function of DNA, as they pair with each other (adenine with thymine and cytosine with guanine) to form the rungs of the DNA double helix. This pairing mechanism is fundamental for the processes of replication and transcription, allowing genetic information to be accurately transmitted and expressed within an organism.

In terms of the other options, the first choice incorrectly lists ribose and uracil, which are components of RNA, not DNA. The third option refers to amino acids and proteins, which are the building blocks of proteins but not components of DNA itself. The fourth choice mentions polypeptides and nucleotides; while nucleotides (which include the nitrogenous bases) are part of DNA, polypeptides pertain to proteins, making this option incorrect in the context of identifying DNA components.