Final answer:
The genetic code refers to the universal system of codons, groups of three nucleotides, that determine the sequence of amino acids in proteins based on the sequences of DNA and mRNA. It functions like a biological language that translates genetic information into the structure of proteins, essential for all life forms.
Step-by-step explanation:
The term 'genetic code' refers to the universal code of three-base codons that encode genetic instructions for the amino acid sequences of proteins. It is the set of rules used by living cells to translate information encoded within genetic material (DNA or mRNA sequences) into proteins. The genetic code is made up of codons, which are groups of three nucleotides within the mRNA. Each codon specifies a particular amino acid that is to be added to a growing polypeptide chain during protein synthesis. For instance, the codon AUG stands for the amino acid methionine, which is also the initiation codon signaling the start of protein synthesis, while GCA represents alanine, and GGC codes for glycine.
This code is remarkably consistent across all known forms of life, with some minor variations. The relationship between a nucleotide codon and its corresponding amino acid is unique, much like an international subscribers dial (ISD) phone code is unique to each country. The discovery that the genetic code was essentially universal enabled a deeper understanding of the fundamental connections among all living organisms, emphasizing that we are all built from the same biochemical foundations.