The first one with the boxing crab and anemone is mutualism.
The second one with the dog and flea is parasitism.
Due to the linneaus system of classification scientist were able to identify organism name , group via standardized system . They have found similarities in the organism like DNA / RNA ( genetic composition), embryonic development etc . so that they can study a organism completely . With the help of this system of classification scientist were able to give a particular name to a organism which is standardrized in the whole universe. It makes easier to all to identify an organism , otherwise different places have different name for a particular species.
The law is something that has been verified
A fossil would from through mineral replacement by replacing the existing material of the animals bones with minerals, to become petrified. The Minerals will keep the fossil preserved longer.
Have a good day!!
