Biology Keystone

Ribosome

A cellular organelle made of protein and RNA where protein synthesis takes place

Translocation

A chromosome alteration in which genes are moved or exchanged between chromosomes

Concentration Gradient

A gradual difference in the concentration of a substance in a solution as a function of distance

Biotic

A living or once-living thing in an ecosytem

Carbohydrate

A macromolecule made of carbon, hydrogen, and oxygen that cells use for energy

ER

A membrane-bound organelle that produces and transports materials for use inside and outside a eukaryotic cell

Mitochondrion

A membrane-bound organelle where energy transformation takes place

Energy Pyramid

A model that shows the amount of energy stored in the bodies of organism at different trophic levels of an ecosystem

Abiotic

A nonliving thing in an ecosystem

Plasma Membrane

A phospolipid bilayer that encloses a cell to separate it from its environment and controls the passage of materials into and out of the cell

Cellular Respiration

A process that breaks down organic molecules such as glucose and captures the released energy in ATP

Enzyme

A protein catalyst

Transport protein

A protein in the plasma membrane that is involved in the movement of molecules and ions into and out of the cell

Symbiotic Relationship

A relationship between two organisms that live together; both organisms may benefit, or one may benefit and the other is harmed, or one may benefit and the other neither benefits or is harmed

Chromosome

A single piece of DNA, made up of genes

Adenosine Triphosphate (ATP)

A small, soluble molecule that provides energy for reactions throughout the cell; ATP releases energy when a phosphate bond is broken

Endemic Species

A species living in the area where it originated

Vestigial Structure

A structure that has lost is original function but suggests that an organism has descended from an earlier organism in which the structure was functional

Catalyst

A substance that speeds up a chemical reaction without being changed itself

Endosymbiosis

A theory that early eukaryotic cells were formed from simpler prokaryotes

Incomplete Dominance

A type of inheritance in which the heterozygous phenotype is a blend of two alleles, neither dominant nor recessive

Co-dominance

A type of inheritance in which two alleles representing homozygous phenotypes are equally expressed

Dominant

A type of inheritance that is expressed when only one allele or both alleles shows the genotype

Prokaryote

A unicellular organism lacking a nucleus and membrane-bound organelles

Allele

A version of a gene due to a variation in the nucleotide sequence

Scientific Theory

An explanation for a broad range of observations based on data, that provides a framework that can be used to make predictions about the natural world

Golgi Apparatus

An organelle in eukaryotic cells that processes materials for release from the cell

Chloroplast

An organelle in plant cells that captures sunlight and transforms it to chemical energy

Eukaryote

An organism made of one or more complex cells with DNA contained in a nucleus and specialized membrane-bound organelles

Decomposer

An organism that gets its energy by breaking down dead or decaying matter, making nutrients available for other organisms

Consumer

An organism that gets its energy by feeding on other organisms

Producer

An organism that uses sunlight as its energy source

Terrestrial

Associated with land

Aquatic

Associated with water

Allele Frequency

How often an allele occurs in a population, its relative frequency

Macromolecules

Large, complex molecules made of chains of smaller molecules; includes lipids, carbohydrates, proteins, and nucleic acids

Unicellular

Made up of one cell

Lipids

Organic compounds composed of carbon and hydrogen and relatively little oxygen that are insoluble in water

Monomers

Small, building block molecules that combine through chemical reactions to form large polymers

Gametes

Specialized cells used in reproduction

Analogous Structures

Structures in different organisms that have the same function but are different in form and inheritance

Frame-shift Mutation

The addition or deletion of one or more nucleotides that changes the order in which they are grouped into codons

Concentration

The amount of a substance, the solute, dissolved in a given volume of water or another substance, the solvent

Cell

The basic unit of life

Evolution

The change in allele frequencies over time that results in new species developing from existing species

Ecosystem

The community of living organisms and nonliving elements of an area

Founder Effect

The decrease in genetic variation when a new population arises from a small number of individuals

Biosphere

The ecosystem of the planet Earth, made up of all biomes

Crossing-over

The exchange of genetic material between homologous chromosomes in meiosis I that results in unique sister chromatids

Phenotype

The expression of a trait

Nondisjunction

The failure of chromosomes or chromatids to separate during meiosis or mitosis

Cytokinesis

The final stage of the cell cycle, during which the cytoplasm divides to form two daughter cells

Interphase

The longest stage of the cell cycle, during which the cell grows, replicates its DNA, and prepares to divide

DNA

The molecule that stores genetic information in living things

Passive transport

The movement of a substance across the plasma membrane without any input of energy

Biogeochemical Cycles

The movement of abiotic factors such as carbon, oxygen, nitrogen, and water between living and nonliving parts of an ecosystem

Diffusion

The movement of molecules or ions down a concentration gradient until it reaches equilibrium

Active Transport

The movement of particles from an area of low concentration across a membrane to an area of high concentration, using ATP as an energy source, to build up a concentration gradient

Osmosis

The movement of water from an area of higher water concentration through permeable membranes to an area of lower water concentration; a form of passive transport

Community

The populations of different species that inhabit a particular area

Trophic Level

The position of an organism in a food chain or web, as a producer, consumer, or decomposer

Cloning

The practice of reproducing an organism that is genetically identical to the original

DNA Replication

The process by which DNA makes an exact copy of itself

Semiconservative Replication

The process by which a double strand of DNA separates and each strand serves as a template for replication, producing new DNA that consists partially of new material and partially of the original

Endocytosis

The process by which extracellular materials are taken into the cell by forming a membrane vesicle around it

Exocytosis

The process by which substances are released from the cell into the extracellular environment via vesicles that fuse with the plasma membrane

Transcription

The process in which the genetic information DNA is copied onto a strand of mRNA

Translation

The process in which the instruction on a strand of mRNA is used to produce a protein

Meiosis

The process of cell division that produces gametes

Homeostasis

The process of maintaining a stable internal environment

Biome

The similar ecosystems of a large geographic area with species adapted to that environment

Cell Cycle

The stages of a cell's life leading to division and duplication; interphase, nuclear division, and cytokinesis

Ecology

The study of the relationships between organisms and their environment

Cohesion

The tendency of water molecules to stick to each other

Adhesion

The tendency of water molecules to stick to other surfaces

Facilitated Diffusion

The transport of substances across the plasma membrane with the assistance of transport proteins; does not require energy

Competition

When two organisms or species compete for limited resources, such as territory, food, water, or mates in the same enviroment