Eli5: What does it mean to “sequence” a specie’s genetic code (or “genome”) if no two individuals have the same genetic code ?

Question

Eli5: What does it mean to “sequence” a specie’s genetic code (or “genome”) if no two individuals have the same genetic code ?

In: Biology

Answer 1

First off, you are right that you sequence an individual and not a whole species–however, species tend to be very close in genetic code, especially compared to other species further out in the tree of life, so an individual can be a very good representative of a species.

Second, to “sequence” something is to literally identify the full “sequence” of genetic code bases (A/C/T/G) making up all the genetic material of that individual’s original code. This might be split up among chromosomes and different locations and such, but most of it is all a linear series of these 4 bases in a specific order.

A “genome” is another word for this full sequence.