from what i understand they are 100% female. the reason is because the plants are all female. they then use different stress factors (food, ph, light, chemicals etc.) to make the plant grow male "bananas". this happens because the plant believes (and is programmed genetically to) make pollen to carry on the species. since the plants are 100% female you get 100% female seeds. you won't get near as many as you normally would, but you get all female seeds none the less.

hope this helps!

-shake