Final answer:
The genetic code is a set of rules used to convert information in DNA and mRNA into proteins, involving transcription and translation. Transcription copies DNA into mRNA, and translation uses that mRNA, along with tRNA and rRNA, to synthesize proteins. This process is nearly universal across all living organisms.
Step-by-step explanation:
The genetic code is the set of rules by which information encoded in genetic material (DNA or mRNA sequences) is translated into proteins (amino acid sequences) by living cells. This complex process involves two main steps: transcription and translation.
During transcription, a segment of DNA is copied into mRNA, which carries the code out of the nucleus of the cell. Then, translation occurs, in which the mRNA is read in triplets, known as codons, and these codons dictate the order of amino acids in a protein.
Each codon specifies a single amino acid or a stop signal for polypeptide synthesis. For instance, the DNA sequence ACGGGTAAGG would be transcribed into the mRNA sequence UGCCCAUUCC, and this code is then read by the ribosome to make a protein.
An important aspect to note is that the genetic code is nearly universal for all organisms, underscoring the shared evolutionary heritage of life on Earth.
Translation additionally involves two other forms of RNA: transfer RNA (tRNA) and ribosomal RNA (rRNA). The tRNA molecules align with the appropriate codons on the mRNA strand and add the corresponding amino acids to the growing polypeptide chain.