Final answer:
The genetic code is a system of triplet base codons in mRNA that dictate which amino acids are added during protein synthesis. It is universal, showing few variations across different forms of life, and is crucial for the accurate construction of proteins.
Step-by-step explanation:
The genetic code refers to the universal code of three-base codons that encode genetic instructions for the amino acid sequences of proteins. This code is expressed as sequences of nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U) in an mRNA chain. The sets of three bases, called codons, act as code words that specify particular amino acids during protein synthesis. For example, the codon AUG codes for the amino acid methionine, serving as the initiation signal for translation as well as coding for an amino acid.
Despite variations in the genetic code among different organisms, the fundamental structure and the majority of codon assignments are universal. This reflects a shared evolutionary heritage and reinforces the genetic code's role as an essential informational framework for life. The arrangement of the 64 triplet codons showcases the code's robustness and redundancy, ensuring that proteins are built accurately even in cases of minor mutations or errors in the DNA sequence.