Hi Alexandra!
Thanks for asking! The genomic size represents the region you are viewing or the annotation you have selected, which is the number of base pairs (bp) from the start to the end. In this case, it looks like you are viewing the GHRL transcript on the reverse strand, displaying loci from chromosome 3, a genomic range of the transcription start position to the transcription end position.
10,292,947 - 10,285,750 = 7,197 + 1 = 7,198 base pairs.
Another example: if we were looking at a region of 1 base pair, which you can see by turning a SNP track on "full" and selecting a SNP, the position would be X - X = 1. For example:
dbSNP: rs9411476
Position: chr9:133252214-133252214
Band: 9q34.2
Genomic Size: 1
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user guide for navigating the browser:
If you are new to the UCSC Genome Browser, you might also be interested in some introductory video tutorials about the browser available
from
our training page