Frog dissection next year?

In 7th grade next year, we have to dissect a frog for science. I am highly against animal cruelty and told my mom I didn't want to do it. She said she would ask the science teacher if I could skip it and work on something else but she's the kind of person who says things then says it's not so bad. I really feel uncomfortable doing this and refuse to take "suck it up" as an answer. My teacher is really nice and I know from having her as a home room teacher this year, that she will probably call me out of class one day and talk to me about what ever because she has done it about three times in the past. And I also am guessing that she wil tell me that it's not so bad and to just get it over with. I don't want to- and I won't. You don't have to kill something for no reason. You don't need a living- well it would be dead now- creature to examine- you COULD just use a model. Do you think they'll let me do some project to boost my grade or is this a must do or fail? And don't tell me that I just have to because I will not and you can't make me change my mind. And did you hve to do this too?