Final answer:
The genetic code is universal, but there are a few exceptions. Mitochondria have their own genetic code, and some bacteria use a slightly different code. These exceptions provide variation in the genetic code across different organisms.
Step-by-step explanation:
The genetic code is described as universal, meaning that virtually all species use the same genetic code for protein synthesis. However, there are a few exceptions to this rule. While these exceptions are relatively rare, they do exist and provide some variation in the genetic code across different organisms.
One example of an exception is found in the mitochondria of certain organisms. Mitochondria have their own genetic code, known as the mitochondrial genetic code, which differs slightly from the standard genetic code used in the cell's nucleus.
Another example is the genetic code used by some bacteria, which may differ in a few codon assignments compared to the standard genetic code.