Rights in School?

The other day, my sister came home from school very upset. She's a 7th grader at Washburne, and in her science class they're beginning to talk about dissecting frogs. Everyone in our family is Vegetarian, and we all believe strongly in animal rights, so naturally we are against the dissecting of frogs. After her class was over, my sister went up to her science teacher and told him that she didn't feel comfortable dissecting the frog, since it was something she strongly disagreed with. He asked her if she ate meat, and she said no, and explained to him why she felt so strongly about animal rights. He told her he understood, but that there was nothing he could really do about it, and if she didnt dissect the frog, she would get a failing grade. The teacher could tell how big of a deal this was to my sister, and i feel that it is really unfair that he still told her that she had no other option. Especially since there are many other options, like virtual dissections, that help kids learn the same things they would in a real dissection. The teacher put my sister in a very hard position, and i think he used his authority against her. He definitly should have tried to see it from her perspective, and not be so close minded