Answer:
1) It's called taxonomy
2) There are 7
3) The basic difference between them is Monera are unicellular and prokaryotic cellular structures, whereas Protista are unicellular and eukaryotic cellular structure. Cell organelles are absent in Monera, but Protista is well-defined and has membrane-bound organelles.
4) Reptiles and Fish belong to kingdom Animalia
The first species that colonizes new of undistributed land is called as pioneer species, or simply pioneers. If you check the meaning of pioneer, it's a type of person or entity that became the first to explore or exploit a certain something. In this case, they were the first species who explores the lands to create a society.