Tee, I think we would have to ask the bees that.
I don't think there is any conclusive research as to which particular egg, if any, gets to become a queen. Unless one says that the egg laid in a queen cell is the one chosen to become a queen.If you look closely at the photo of the queen larvae in Mindy's article you can see the larvae are not in the traditional "cells"; the queen "cells" are shaped sort of like a peanut & protrude from the normal surface of the sheet of cells. Generally these cells are only built by the workers when the present queen is getting old or when it is swarming time. The swarm will need a queen when it leaves the colony. At that time (swarming time) the queen will lay eggs in the "peanut cup". The eggs are mol all the same but it is the royal jelly which makes the difference in the resulting bee --- worker, drone or queen. The queen can decide which eggs she fertilizes & drones do not get fertilized; only workers & queens do. MIndy would have to come back on & tell us because I can't remember the exact # of days for each but drones take X days to maturity (from egg to bee) then workers take longer by X days & finally queens take the longest. I want to say queens are 22 days & workers are 18 but I'm not sure.