Final answer:
The genetic code is true to be universal, supporting the idea that all life on Earth shares a common ancestry. With minimal exceptions, this code is used for protein synthesis across different species, demonstrating a close evolutionary relationship and the conservation of codons.
Step-by-step explanation:
True, the genetic code is considered to be universal, present in all organisms with a few exceptions. Virtually all species use the same genetic code for protein synthesis, which is powerful evidence of a common origin. For example, an mRNA encoding for a protein in horses could potentially be introduced into a tulip cell, leading the tulip to produce horse protein. This demonstrates the incredible conservation of codons across different life forms.
The genetic code's universality demonstrates that all life shares a common evolutionary history. It is mostly unambiguous, meaning that each codon signifies a single amino acid, with the exceptions of methionine and tryptophan, where each is coded by only one codon. The nature of the genetic code with its near-universality and the fact that it is unambiguous provides a compelling argument for the common descent of all organisms.