Earth's lies above the mantle and directly interacts with living systems

Earth's crust lies above the mantle and directly interacts with living organisms.
Earth is divided into four systems: the lithosphere, hydrosphere, biosphere and atmosphere. The lithosphere is the solid outer layer of Earth that consists of the crust and the solid upper part of the mantle and is divided into the tectonic plates. The crust is a thin cell on the outermost zone of the Earth, lying just above the mantle.