Final answer:
The genetic code is nearly universal among organisms, dictating how sequences of DNA and RNA are converted into proteins. It consists of 64 codons that translate into 20 amino acids, with each codon corresponding to a single amino acid or a specific function in protein synthesis.
Step-by-step explanation:
The genetic code is a set of rules used by living cells to translate the information encoded within genetic material (DNA or RNA sequences) into proteins. This code is nearly universal and is shared among virtually all organisms, with a few exceptions. This universality is a powerful testament to the common evolutionary history of life on Earth. The genetic code is represented by 64 triplet codons, each consisting of three nucleotides within the mRNA, and these codons dictate the sequence of amino acids in a protein. The genetic code is both universal—meaning it is consistent across nearly all species—and unambiguous, with each codon specifying a single amino acid or serving a specific function such as a start or stop signal in protein synthesis.
The remarkable feature of the genetic code is that only 64 codons correspond to the 20 amino acids that make up proteins, with some amino acids being encoded by more than one codon. Each group of three nucleotides, known as a codon, corresponds to one amino acid or a termination signal during protein synthesis. Because of the genetic code's characteristics, mRNA from one species can often be used in another species to produce the same protein, which provides evidence that all life shares a common origin.