Any part of our mental state can be altered. How? Well, nothing is truely "mental" there is only physical. "Mental" things are actualy combinations of physical reactions in the brain. Anything which is physical has the potential to be structuraly changed, thereby altering any characteristic of the supposed physical trait. To say a straight man cannot sleep with another man is incorrect. If they cannot, then how does a man "jackoff" by himself? In reality we are all bisexual, and we simply do not want to admit that. Because forcing ourselves towards one sexual preference is often easyer for us to do. As humans we look for the easyest way every time, unless the other way can benefit us more in some way.
I'm not sure what you mean by there being a problem with your chromosomes if you're gay. I highly doubt that. A chemical difference in the brain, perhaps, but not a problem on the chromosomes. Could you give an example of an instance of this being true?
I don't think it matters whether it is nature or nurture that makes somebody gay, as long as you keep an open mind about it.
Actualy your chromosomes determine almost everything about you. But, yeah I can't remember where I read that, I'l post the link if I find it.
id have to say its science and unreligious as it is against all christian related religions (Muslim, Christian, Catholic, ...etc) and science since it can detect any potential or existing problems