Which term describes a segment of DNA that codes for a protein?

The term that describes a segment of DNA that codes for a protein is known as a gene. Genes are specific sequences of nucleotides within DNA that contain the instructions for synthesizing proteins, which perform a vast array of functions in the body. Each gene is situated on a chromosome and typically comprises coding regions (exons) and non-coding regions (introns). In essence, genes are the fundamental units of heredity and play a crucial role in determining the characteristics and functions of an organism.

To provide context, a chromosome is a long, continuous strand of DNA that contains many genes, whereas the genome refers to the complete set of genetic material in an organism. An allele is a variant form of a gene that can produce different traits, but it does not refer to the gene itself. This distinction clarifies why the selection of "gene" is the most accurate choice for a segment of DNA that specifically codes for protein.