Q. Which zone separates the crust and mantle ?

Explanation by: Deepak Sahoo

There are five discontinuities inside the earth: Conrad Discontinuity – Transition zone between SIAL and SIMA, Mohorovicic Discontinuity - Transition zone between the Crust and Mantle, Repiti Discontinuity - Transition zone between Outer mantle and Inner mantle, Gutenberg Discontinuity – Transition zone between Mantle and Core, Lehman Discontinuity – Transition zone between Outer core and Inner core.