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

Test your knowledge of the Nebular Hypothesis theory and its role in the formation of the Sun, planets, and moons. Learn about the collapse, rotation, and hydrogen fusion that led to the formation of our solar system. Watch a short video to refresh your understanding.