Now that you mention it...

Hetero doesn't mean normal. It means 'different' or 'other'. So heterosexual simply means attraction to the other sex. Homo as used in the word homosexual means 'same', thus the word means attraction to the same sex. There's nothing inherently offensive about either term.

Definitely. I've never seen heterogene solutions are considered as "normal solution" after all.

Oh, so they're using that root in that word? Because in one language--I don't remember which one--it does mean normal.

^Yes, as for most scientific terms, the roots are either Latin or Greek. Here's a list of link, scroll down and you'll find 'hetero'.

If "hetero" meant "normal", there would be a problem. But, it just means "different". Trust me, I'm not trying to be rude here, but always check your sources.

Not really. Because homosexual is just like homo sapien, so we're human.

since the megority of people are hetrosexual than its normal and i dont really care...

there is no specific meaning for normal. there's the norm, but you can't define normal! it shouldn't even be a word!! *fumes*

When was heterosexual offensive?
I'm learning about genetics and heterozygous and homozygous comes up a lot. Obviously, hetero does not stand for normal, the prefix means means different (having different alleles for a particular trait; heterozygous). Homo means same (having the same alleles of a particular trait; homozygous). Sexual is self-explanatory, so heterosexual means attraction to the opposite sex. That isn't offensive, it is just information about a person's sexual orientation.
Here's some other words that uses the prefix 'hetero' link