Question

Please be detailed. Discuss the concept of the universality of the genetic code. Mention the exceptions to this universality. What are your thoughts on how the universality of the genetic code makes recombinant DNA technology possible?

Answer 1

The same amino acid, whether from a virus to a human being or even a tree, is specified by the same codon. We call this concept the universal applicability of the genetic code. This an mRNA isolated from the oviducts of chicks will go on to produce ovalbumen even in bacterium such as E. coli. Not only that, but this ovalbumen will be indistinguishable from the original one.  

The exceptions to this model are:
1) in some ciliates, the termination codons, UAA and UGA, actually code for glutamine
2) In mitochondrial genes, AGG and AGA that generally code for arginine, act as stop signals in human mitochondria, UGA makes a tryptophan, while AUA denotes methionine.

The universality of the genetic code allows us to make recombinant DNA by introducing genes of interest in their vector forms into appropriate hosts and obtaining the products (generally proteins) of interest from their rapid growth and proliferation which is perpetuated in a steady growth kinetic bioreactor model.