Molecular biology is a field of biology that looks at the molecular machinery of life. The field was founded in the early 1930s, though the phrase was only used in 1938 and the field didn't take off until the late 50s and early 60s. Since then, progress in the field has been massive.
The Ionosphere and the Exosphere (minor layers) are parts of the Thermosphere (major layer). The ionosphere is part of the theremosphere.
Remember to be able to tell the difference between the oceanic crust and the continental crusts. And remember that the lithosphere is composed of the earth's crust and the uppermost part of the mantle. The 3 main layers are the core, mantle and crust. The mantle is composed of the mesosphere and the asthenosphere and the uppermost part of the mantle. That uppermost part of the mantle is what is combined with the crust to make the lithosphere.