What determines the genetic code of a region of DNA?

A. The number off base pairs

B. The number of phosphate groups

C. The order of sugar and phosphate groups

D. The order of nitrogenous bases

D

Explanation:

Like words in a sentence, the DNA sequence of a gene determines the amino acid sequence for the protein it encodes. In the protein-coding region of a gene, the DNA sequence is interpreted in groups of three nucleotide bases, called codons. Each codon specifies a single amino acid in a protein.

The correct answer is option D. "The order of nitrogenous bases".

Explanation:

The four nitrogenous bases are the compounds within DNA that differentiates the nucleotides into adenine (A), guanine (G), cytosine (C) and thymine (T) depending on its structure. The order of nitrogenous bases determines the genetic code of a region of DNA. DNA is translated into protein by triples of nucleotides called codons, the order of the codons determines the sequence of the protein.