yes the whole cannabis plant usually obtains a definite form meaning male or female (like humans a guy has a penis and no breast... lol). How ever some times it can become a hermi meaning that it was a female but then developed male characteristics as well. this usually occurs when the plant receives shock which can happen from a number of things. when they say likely to be 50% male im assuming your talking about what seeds will become and if so it just means that out of 100 seeds 50 will be male and 50 will become female.