What does mapping an organism’s genome mean, and how is it useful?
In: Biology
Almost every cell in an organism contains a bunch of the same DNA. DNA molecules are looooong chains of 4 different molecules called nucletides, named ‘A’ (adenosine), ‘T’ (thymine), ‘C’ (cytosine) and ‘G’ (guanine). The order of these small molecules in DNA is a code. This code is essentially a recipe for the organism to live and grow.
When you sequence an organism’s genome, what you are doing is getting those DNA molecules out of a cell, running them through a machine which essentially says how many A, T, C, and G’s there are, and in what order. To *map* the genome is to find out which parts of the genome actually do stuff, and what that stuff is. The parts that do stuff are mostly genes, which are shortish sequences that code for proteins, which are the building blocks of organisms.
It’s useful, because once we know what parts of the genome do what, we can then compare different organisms in a population for certain genes. We might know that individuals with this gene respond in this certain way to a disease. Genomes can also be used to compare relatedness within and between species. Since the code changes through time, we assume more change=more time since we shared an ancestor.
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