Early Universe and Its Epochs

A point of infinite density and temperature from which the universe is believed to have originated; according to this theory, the universe began as a singularity, an infinitely hot and dense point, then expanded rapidly.

The rapid expansion of space shortly after the Big Bang, stretching tiny quantum fluctuations and seeding the formation of large-scale structures.

The process during the early universe where the first atomic nuclei, primarily hydrogen, were created.

The period when the universe was filled with photons, extremely hot and dense, making atoms unstable; this period ended with the recombination Era.

The era in which the universe cooled down enough for electrons to combine with protons to form neutral hydrogen atoms, allowing light to travel freely, creating the cosmic microwave background radiation.

The period after the Recombination era characterized by a universe filled with neutral hydrogen, with no stars or galaxies; it lasted until the first stars formed.

The process by which a giant molecular cloud of gas and dust collapsed due to gravity, forming the Sun at the center and a spinning protoplanetary disk that eventually formed the planets.

Small, rocky (or icy) bodies formed during the early stages of solar system formation through collisions and sticking together.

The process by which planetesimals grow into larger bodies by collisions and gravitational attraction, eventually forming protoplanets and planets.

The process by which a planet's internal layers separate based on density, forming distinct layers like core, mantle, and crust.

The theory explaining the formation of the Moon, which suggests a Mars-sized protoplanet collided with Earth, ejecting material that eventually coalesced into the Moon.

The most external solid layer of the Earth, composed of lighter rock than the mantle beneath it.

The thick layer of Earth beneath the crust, composed of mostly solid rock, extending to the outer core.

The outermost layer of the Earth's core, composed of liquid iron and nickel.

The innermost, solid part of the Earth's core, composed of iron and nickel, kept solid by immense pressure.

The process by which gases and other volatile materials released from the Earth's interior into the atmosphere through volcanic eruptions and other geological processes.

The condition that distinguishes living organisms from non-living matter, characterized by growth, reproduction, maintaining homeostasis, responding to stimuli, and carrying out metabolic processes.

The process by which cells build complex molecules from simpler ones, requiring energy, usually involving the bonding of smaller molecules to form larger ones.

The breaking down of complex molecules into simpler ones, releasing energy; usually involving the breaking of chemical bonds.

The ability of an organism to maintain a stable internal environment, regardless of external changes; this is essential for survival in changing environments.

The ability of an organism to detect and respond to changes in the environment, allowing it to adapt and survive in a changing world.

The changes an organism undergoes throughout its life, including growth and development.

The process by which living organisms produce offspring, passing on genetic information and ensuring the continuation of life.

The process by which living organisms change over time, adapting to their environments and evolving through changes in genetic material.

The scientific theory that suggests life originated from non-living matter through a series of chemical reactions.

The process by which life arises from pre-existing life; this is the central principle of biology.

A theory that suggests life originated in outer space and was brought to Earth, possibly on asteroids or comets.

The theory suggesting life originated at hydrothermal vents on the ocean floor, which are rich in energy and minerals.

The theory suggesting early life was based on RNA, which could store genetic information and catalyze chemical reactions

The theory proposing early life began on clay mineral surfaces that facilitated the organization and polymerization of organic molecules.

The theory suggesting life started on surfaces of iron and nickel sulfide minerals, providing energy for the synthesis of organic molecules.

A hypothesis that suggests life originated from the formation of microscopic droplets of organic molecules surrounded by a lipid layer, capable of growth, division, and concentration of molecules.

Self-assembling lipid and organic molecules, acting as precursors to cells, possibly forming by encapsulation of organic molecules within membranes.

The process of chemical evolution involving the formation of small organic molecules (precursors) and their polymerization into larger, more complex macromolecules, crucial for life.

A theory explaining the origin of eukaryotic cells, proposing that mitochondria and chloroplasts were originally free-living bacteria that were engulfed by a host cell, forming a symbiotic relationship.

Layered sedimentary rock structures formed primarily by the activities of mats of cyanobacteria, providing evidence of early life.

Microscopic fossils of individual cells or microbial filaments, providing direct evidence of ancient life on Earth.

Preserved organic molecules, such as lipids or isotopic signatures found in ancient rocks, providing indirect chemical evidence of past life.

The process by which new crust is formed at mid-ocean ridges as tectonic plates move apart; this process is also responsible for the creation of new ocean basins.

The process where denser oceanic plates sink beneath continental plates at convergent boundaries, causing volcanic arcs and deep ocean trenches, generating heat and pressure that drive seismic activity.

Areas of intense volcanic activity that are not associated with plate boundaries, caused by plumes of hot mantle material rising through the lithosphere.

Occur where tectonic plates slide past each other horizontally, causing earthquakes and fault lines.

Occur where tectonic plates move apart, creating new crust and mid-ocean ridges.

Occur where tectonic plates collide, causing subduction, mountain ranges, and volcanic arcs.

Cells lacking a nucleus or membrane-bound organelles; found in Bacteria and Archaea.

Cells containing a nucleus and membrane-bound organelles; found in plants, animals, fungi, and protists.

The concept that a species is a group of individuals that can interbreed in nature and produce viable, fertile offspring, but are reproductively isolated from other such groups.

The concept that defines a species based on observable physical characteristics, shape, size, and structure.

The concept that defines a species based on its unique role and interactions within the ecosystem.

The concept that defines a species as the smallest group of organisms that share a common ancestor and can be distinguished from other groups by unique traits.

The concept that defines a species based on genetic similarity or distinctness, using molecular data like DNA or RNA sequences.

The concept that defines a species as a single lineage of populations that maintains its identity from other lineages and has its own evolutionary trajectory.

A system for organizing living things into groups based on their similarities and evolutionary relationships.

The three-domain system of life, which includes Bacteria, Archaea, and Eukarya, reflecting evolutionary relationships between organisms based primarily on rRNA sequence comparisons.

The process of dividing Earth’s history into eons, eras, periods, epochs, and ages, reflecting major geological and biological events that shaped the planet.

The study of Earth’s history, examining physical, chemical, and biological changes over time.