what is its interior format?
It is divided into layers by their chemical or physical (rheological) properties.
Earth
Earth's interior, like that of the other terrestrial planets, is divided into layers by their chemical or physical (rheological) properties. 
what happens when a keystone species is removed from an ecosystem apex The ecosystem would be dramatically different or cease to exist altogether. can you explain the meaning of this category? A keystone species is a species which has a disproportionately large effect on its natural environment relative to its abundance what animals fall under this category? wolf who introduced this system? Robert T. Paine what is the meaning of the environment mentioned above? It encompasses all living and non-living things occurring naturally. where is this environment applicable? Earth or some parts of Earth what is this place? Earth is the third planet from the Sun and the only astronomical object known to harbor life. how was it formed? A solar nebula partitions a volume out of a molecular cloud by gravitational collapse, which begins to spin and flatten into a circumstellar disk, and then the planets grow out of that disk with the Sun what makes this astronomical object the only place to have life? Chemical reactions led to the first self-replicating molecules
wiki:1595168
Earth [SEP] Internal structure
Earth's interior, like that of the other terrestrial planets, is divided into layers by their chemical or physical (rheological) properties. The outer layer is a chemically distinct silicate solid crust, which is underlain by a highly viscous solid mantle. The crust is separated from the mantle by the Mohorovičić discontinuity. The thickness of the crust varies from about under the oceans to for the continents. The crust and the cold, rigid, top of the upper mantle are collectively known as the lithosphere, which is the region where tectonic plates are found. Beneath the lithosphere is the asthenosphere, a relatively low-viscosity layer on which the lithosphere rides.