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.
There are five distinct sub-layers of the Epidermis: 1  Stratum corneum: the outermost layer, made of 25-30 layers of dead flat keratinocytes. Lamellar granules provide water repellent action and are continuously shed & replaced. 2  Stratum lucidum: Only found in the fingertips, palms of hands, & soles of feet.