Earth and Life Science -First Semester (1st Periodical)

Biological Macromolecules

• Carbon is the primary component of Biological Macromolecules

Origin of Life

• In 1952, Stanley Miller and Harold Urey discovered the building blocks of life, including amino acids, through an experiment simulating early Earth's atmosphere
• Their experiment revealed that the conditions on early Earth were suitable for the formation of complex molecules, supporting the theory of chemical evolution

Early Earth and Extremophiles

• During the extreme conditions on early Earth, thermophiles and other extremophiles thrived
• These organisms were able to survive in environments with high temperatures, high pressures, and high salinity

Oxygen Production

• Cyanobacteria were the first organisms to produce oxygen gas through photosynthesis
• Oxygen levels rose to their current level about 2.7 billion years ago

Atmosphere

• The stratosphere is the layer of the atmosphere that contains the ozone layer
• The troposphere is the thinnest part of the geosphere
• The biosphere includes all the microbes, plants, and animals
• The ozone layer is responsible for absorbing and scattering solar ultraviolet radiation
• The lithosphere is the thickest part of the geosphere

Geology

• Weathering is the process by which the surface of the earth gets worn down
• Deposition is the geological process in which sediments, soil, and rocks are added to landforms or land masses
• Mechanical weathering is often triggered by earthquakes, volcanic eruptions, or heavy rainfall

Rocks

• Foliated metamorphic rocks have mineral crystals arranged in layers or bands
• Non-foliated metamorphic rocks have mineral crystals arranged randomly
• Mafic magma has low silica content, high temperature, low viscosity, and low gas content
• Contact metamorphism occurs when a large mass of rocks is exposed to differential stress and high temperature
• Sedimentary rocks are formed through the processes of erosion, deposition, and lithification