I though I would start by covering some of the basics of genetics and breeding in as simple terms as possible and without all the algebra
So as with every living creature on earth, these plants included have their own sequence of dna which is defined by the plants ancestors and aswell as it's environmental pressures this process is known as which we call evolution and will typically result in dominant traits which fit the environment
Now as breeders we are not always looking to pass on these dominant genes ie tall plants are dominant in the wild due to the struggle for light but in an indoor/controlled environment a more stout and bushier structure is more appropriate. Now this doesn't mean that the short gene has been completely wiped out in the wild setting, just that there are dominant genes restricting its expression in the majority of the population
If we're were to then select 2 pheno types that have expressed the short trait, we have a much high likely hood of seeing the recessive genes paired with a more recessive trait within its double helix.
At this point it's worth mentioning that not all traits will neatly fall into these 2 categories. There are traits which are dominant to dominant traits and recessive to recessive trait which simply means some traits will only be expressed when paired with a matching recessive trait. This is the case with strains that are often clone only as they posses double recessive traits and any cross breeding results in the target trait being lost
In a wild environment these pressures will define what is required by the plant to survive onto the next generation ie damp resistant roots in a damp area or ruderulis is areas with a short photo period. These traits then become dominant in that particular gene pool (that area or environment)
Alright, so now your probably asking yourself... how do I know what traits are dominant and what is recessive within the cannabis family. Well, we don't know. As cannabis can be found wild in 2/3 the world's land mass, there is such a wide variation to the plants evolution, that depending where you start in regards to strain, these plants will have potentially polar opposites dominance and recession
So where do we go from here?
Well, to get a true understanding of your own gene pool it's recommended to full cycle a male 3 times across 6 mothers to define a single males inheritable traits and females potentially alot more
Just to add a few points of interest
When breeding a female which has either been forced male or stressed into forming male parts to allow for self pollination will produce what is known as S1 seeds or "selfie gen 1" and if a reversed females pollen is used with a different plant to create a new strain this is an F1 or female gen 1 and finally we have the nature's way R1 which is a natural male fertilising a natural female to produce regular seeds. The first 2 mentioned will result in 99.9% feminised seeds and the 3rd with a 50-50 chance of either
I will try add to this as and when topics come up or are discussed. Please leave feed back and your own insights

Thanks for reading
Sent from my SM-G900F using Tapatalk