Final answer:
The correct word to complete the sentence is 'nucleotides.' In DNA, nucleotide order determines the sequence of amino acids in a protein, starting with transcription and culminating in translation.
Step-by-step explanation:
The order of the nucleotides in a section of DNA decides the protein that is synthesized by that section of DNA. Nucleotides are the building blocks of DNA and are composed of a nitrogenous base, a phosphate group, and a sugar molecule. The sequence of these nucleotides' codes for the amino acid sequence of a protein.
The process starts with the transcription of DNA into mRNA, with the base thymine (T) being replaced by uracil (U) in RNA. The mRNA is then read in codons (sets of three bases) during translation to form a chain of amino acids making up the protein.
A change in the nucleotide sequence can lead to the production of a different protein, underscoring the importance of the correct nucleotide order in DNA for accurate protein synthesis.