epic epic study guide

awa

Big Bang

The scientific theory that the universe began from a single, extremely hot and dense point around 13.8 billion years ago and has been expanding ever since.

Quarks

Fundamental particles that combine to form protons and neutrons.

Gluons

Particles that act as the "glue" holding quarks together inside protons and neutrons.

Singularity

A point in space with infinite density and gravity, believed to be the starting point of the Big Bang.

Inflation

A rapid expansion of the universe that occurred a tiny fraction of a second after the Big Bang.

Protons

Positively charged particles found in the nucleus of an atom.

Neutrons

Neutral particles found in the nucleus of an atom.

Electrons

Negatively charged particles that orbit the nucleus of an atom.

Atoms

The smallest unit of matter that retains the properties of an element.

Nebula

A large cloud of gas and dust in space; often the birthplace of stars.

Hydrogen

The simplest and most abundant element in the universe; has one proton and one electron.

Helium

A light element formed by fusion in stars; has two protons and two neutrons.

Galaxies

Massive systems of stars, gas, and dust bound together by gravity.

Dark Energy

A mysterious force causing the accelerated expansion of the universe.

Dark Matter

Unseen matter in the universe that has mass and gravity but does not emit light.

Supernova

A massive explosion that occurs at the end of a large star's life cycle.

Prokaryotes

Simple cells without a nucleus, such as bacteria.

Organelles

Specialized structures within cells that perform specific functions.

Organelle

A single structure inside a cell with a specialized job (e.g., mitochondrion).

Nucleus

A membrane-bound organelle in eukaryotic cells that contains DNA.

Nucleoid

The area in a prokaryotic cell where DNA is located (not enclosed by a membrane).

Ribosome

A structure that makes proteins by reading RNA instructions.

Cytoplasm

The fluid-filled space inside a cell where organelles are found.

Cell Membrane

A flexible barrier that surrounds the cell and controls what enters and leaves.

Cell Wall

A rigid structure outside the cell membrane found in plants, fungi, and bacteria for support and protection.

Flagella

Long, whip-like tails that help some cells move.

Cilia

Short hair-like structures that help move a cell or move fluid past the cell.

Asexual Reproduction

A method of reproduction involving only one parent, producing genetically identical offspring.

Photosynthesis

The process by which plants and some bacteria use sunlight to make food (glucose) from carbon dioxide and water.

Cyanobacteria

Photosynthetic prokaryotes (also called blue-green algae) that were likely the first organisms to produce oxygen.

Ozone Layer

A layer in Earth's atmosphere that absorbs harmful UV radiation, formed partly due to oxygen released by early photosynthesizers.

Eukaryotes

Cells that have a nucleus and membrane-bound organelles.

Protists

A diverse group of mostly unicellular eukaryotic organisms that don't fit into plant, animal, or fungi groups.

Mitochondria

Organelles that produce energy (ATP) through cellular respiration.

Chloroplast

Organelles in plant cells where photosynthesis takes place.

Anaerobic

Processes or organisms that do not require oxygen to function.

Aerobic

Processes or organisms that require oxygen.

Cellular Respiration

The process by which cells break down glucose to release energy (ATP), usually using oxygen.

Sexual Reproduction

A type of reproduction involving two parents and producing genetically unique offspring.

Cellular Specialization

When cells develop specific functions in multicellular organisms.

Xylem

Vascular tissue in plants that transports water and minerals from roots to the rest of the plant.

Phloem

Vascular tissue that transports sugars and other nutrients throughout the plant.

Extremophiles

Organisms (mostly prokaryotes) that live in extreme environments like hot springs or deep-sea vents.

Unicellular

Made up of a single cell.

Multicellular

Made up of more than one cell, often specialized for different functions.

Cambrian Explosion

A period about 540 million years ago when a rapid increase in the diversity of life forms occurred.

Bryophytes

Non-vascular plants like mosses; they require water for reproduction.

Pterophytes

Ferns and their relatives; vascular but reproduce via spores.

Gymnosperms

Seed-producing plants like conifers that do not form flowers.

Pollination

The transfer of pollen from the male part of a plant to the female part for fertilization.

Seeds

Structures that protect and nourish the plant embryo; allow plants to survive harsh conditions.

Vascular

Having specialized tissues (xylem and phloem) for transporting water and nutrients.

Avascular

Lacking vascular tissue; depends on diffusion for transport.

Desiccation

Extreme dryness; a challenge plants had to overcome to live on land.

Angiosperms

Flowering plants that produce seeds enclosed in fruit.

Flowers

Reproductive structures of angiosperms that produce pollen and ovules.

Fruit

A mature ovary of a flower that contains seeds; helps in seed dispersal.

Amphibians

Vertebrates like frogs and salamanders that live part of their lives in water and part on land.

Metamorphosis

A biological process of transformation from an immature form to an adult form (e.g., tadpole to frog).

Reptiles

Cold-blooded vertebrates with scales and internal fertilization (e.g., snakes, lizards).

Mammals

Warm-blooded vertebrates with hair or fur, and females produce milk for young.

Hominid

A group of primates that includes modern humans and their ancestors.

Placenta

An organ in most mammals that nourishes the embryo during pregnancy.

Homo erectus (H. erectus)

An extinct human ancestor known for being one of the first to use fire and migrate out of Africa.

Homo heidelbergensis (H. heidelbergensis)

An early human species that may be a common ancestor of Neanderthals and modern humans.

Homo habilis (H. habilis)

One of the earliest members of the genus Homo; known for using simple tools.

Australopithecus

An early hominin genus; famous for the fossil "Lucy."

Homo ergaster (H. ergaster)

A possible African ancestor of Homo erectus; showed more advanced tool use.

Neanderthals

An extinct species of hominids closely related to modern humans; adapted to cold climates.

Endothermic

Organisms that maintain a constant internal body temperature (warm-blooded).

Exothermic

Organisms that rely on external sources to regulate body temperature (cold-blooded).

Genetic Variation

Differences in DNA sequences among individuals in a population.

Allele

A version of a gene (e.g., for eye color, you may have a blue or brown allele).

Allele Frequency

The proportion of a specific allele among all alleles in a population.

Genetic Drift

Random changes in allele frequencies, especially in small populations.

Founder's Effect

When a new population is started by a few individuals, leading to reduced genetic variation.

Bottleneck Effect

A sharp reduction in population size due to a disaster, reducing genetic diversity.

Gene Flow

Movement of alleles into or out of a population due to migration.

Relative Fitness

An individual's ability to survive and reproduce compared to others in the population.

Adaptive Evolution

Evolution that results in a better fit between an organism and its environment.

Speciation

The formation of new species.

Species

A group of organisms that can interbreed and produce fertile offspring.

Macroevolution

Large-scale evolutionary changes over long periods, like the formation of new species or groups.

Microevolution

Small changes in allele frequencies within a population over time.

Reproductive Isolation

When populations can no longer interbreed due to physical or behavioral barriers.

Hybrids

Offspring resulting from the mating of two different species.

Zygote

The first cell formed when a sperm fertilizes an egg.

Prezygotic Barriers

Reproductive barriers that occur before fertilization (e.g., mating behavior, timing).

Postzygotic Barriers

Barriers that occur after fertilization, often resulting in infertile or non-viable offspring.

Habitat Isolation

When two species live in different environments and don't meet to mate.

Temporal Isolation

When two species breed at different times or seasons.

Behavioral Isolation

When two species have different mating behaviors.

Mechanical Isolation

When structural differences prevent mating.

Gametic Isolation

When sperm and egg cannot fuse to form a zygote.

Reduced Hybrid Viability

A hybrid offspring that doesn't survive well.

Reduced Hybrid Fertility

A hybrid that survives but is sterile (e.g., mule).

Niche

The role or job of an organism in its ecosystem.

Hybrid Breakdown

When the first-generation hybrids are fertile, but later generations are weak or sterile.

Allopatric Speciation

New species form due to geographic separation.

Sympatric Speciation

New species form in the same area, often through genetic differences or behavior.