Make sure the navigation button at the top of the map is selected for the duration of this assessment so that you can see the menu. turn on the genotypes button in the "layers" menu. on the map, click on the green magnifying glass icon on lily’s chromosomes until you reach zoom level 9. the brca1 mutation (indicated here in red lettering) results from a change in a single nucleotide with a guanine base (g) to a nucleotide with a thymine base (t). such a mutation could result from an error during which process?