The spheres that are formed by remains of living things with a black hard surface are known as BIOSPHERE.
This is because the Biosphere is a combination of both living organisms (biotic) and nonliving organisms (abiotic) to form an ecosystem. It also includes the lithosphere, atmosphere, and hydrosphere.
Hence, the remains of living things are part of the biotic part, while a black hard surface is a form of abiotic part of the biosphere.
The state laws argued for "separate but equal schooling". It was found that the separate schools (for Blacks and Whites) were very far from equal, meaning that some of the US Citizens were denied the same liberties others got solely for their skin color.