1. I don't think so but in some cases it may or may not, because it depends upon how strong bond you have among your self firstly in friendship we need the trust  and blind believe on each other it makes the strong bond among your self.if the true friends are not together also but they bother about each other and always think of them, if it is a true friendship definitely it lasts forever.
2. every thing has an advantage as well as disadvantage if animals are not used in researches so they have to do that experiment on humans, if that experiment will fail definitely that human may loose his life. I think as per my knowledge no human will be ready to give up their lives so scientists first prefer animals to do experiment.