Conditional clauses

Hello,

I have a basic question regarding conditional clauses and possible differences in meaning.

I had to fill in the next sentence for an English assignement:

'What would happen if one ........ [MUTATE] the signal sequence on the receptor molecule?'

This part is about the conditional clauses.

I have three possible answers. The first one is the most fitting when talking about conditional clauses (in my eyes). I'm not 100 percent sure wether the 2nd and 3d are grammatically correct and if they are, wether they are considered acceptable English.

1. What would happen if one mutated the signal sequence on the receptor molecule?

2. What would happen if one would mutate the signal sequence on the receptor molecule?

3. What would happen if one were to mutate the signal sequence on the receptor molecule?

Personally I think all three sound right, but the second one looks a bit redundant with the usage of would twice in a row. I mean, better sentences could be made.

I can't really tell a difference in meaning between the first two. The third sounds a bit more hypothetical than the first two, but for the rest I don't see a lot of difference.

Is there any difference between these sentences? Which are grammatically incorrect (if any)? Which are the most acceptable?

Also feel free to correct me on any mistakes I make in my post(s). I'm rather excited to learn English again because it has always been my favourite language.