lmfao at the Moss....omg, to funny.
Take two different strains (1 male, 1 female) Cross those strains and the resulting s33ds are F1. The F1's have 10 chromosones from each parent plant. Grow these s33ds, select your phenos and cross them and the resulting s33ds are F2. They have 10 chromose from each of the parents of the F1's. Grow F2's, select, cross, and resulting stock are F3's, and so on until you create an IBL.
Backcrossing is when you take one of the F2, F3's and backcross to the original, or perhaps the F1 to perhaps inject back more of the orignal parnet traits.
Bx1, first geenration backcross. Bx2, second generation backcross (i.e using a Male and or a female from the Bx1) and corssing with the orignal parent.
Hope that helps.
Peace, DST