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.
The layer below the rigid lithosphere is a zone of asphalt-like consistancy called the Asthenosphere. The asthenosphere is the part of the mantle that flows and moves the plates of the Earth. The Mantle. The mantle is the layer located directly under the sima.