OK this is going to be under a readmore because it's pretty much me having thoughts about the genetics of werewolves (please note that I'm not a geneticist and I'm basing this off a very rudimentary knowledge of all this sort of stuff).
So pretty much I was thinking about whether a werewolf and a human would have human or werewolf babies and this is what I came up with.
The werewolf gene is dominant over the human gene, but it is extremely rare (similar to six-fingeredness). A beta who was turned would have the combination Ww, as would most betas who were born werewolves, but alphas always have the combination WW, which is what gives them the potential to have that extra power, but the nature of being the alpha makes them that.
So if a beta who is only a beta and can never be an alpha has kids with a human, the kids have a 50/50 chance of being human and a 50/50 chance of being wolves.The kids of a beta who had alpha-potential or of an alpha with a human would all be werewolves, 100% of them, but none of them would have alpha potential.
You can do the maths for the rest of this. Just whip up some very quick punnet squares or something. This is why being the alpha runs in families and you get things like the Hale Pack, because those are the people whose kids have the highest chance of having alpha-potential and ascending to the rank of alpha when the current alpha dies.