Biology Key Terms: Cell Theory, Taxonomy, and Evolution

Binomial naming system

A formal system for naming organisms with a two-part name: the genus and species.

Biology

The scientific study of life and living organisms.

Cell

The basic unit of structure and function in living things

Cell theory

The fundamental scientific theory that all living organisms are made of cells, and that cells are the basic units of life.

Characteristics (of life)

The traits that are shared by all living organisms, including order, response to the environment, reproduction, growth and development, energy processing, regulation, and evolutionary adaptation.

Classification

The process of arranging organisms into groups based on their similarities.

Common ancestor

An ancestor that two or more different species have in common.

Community

A group of different species living and interacting in the same area.

Ecosystem

A community of organisms and their physical environment interacting as a system.

Emergent properties

New properties that arise from the arrangement and interaction of parts as complexity increases. For example, a single neuron doesn't have a thought, but a brain does.

Eukaryote

An organism whose cells contain a nucleus and other membrane-bound organelles.

Genotype

The genetic makeup of an organism, referring to the specific set of genes it possesses.

Hierarchical units

A system of classification in which smaller groups are nested within larger ones, from broad categories like kingdom down to specific ones like species.

Observation

The process of gathering information about the world using one or more of the five senses.

Organelle

A specialized, membrane-bound structure within a cell that performs a specific function.

Organism

A single, individual living thing.

Phenotype

The observable physical and physiological traits of an organism, which are determined by its genotype and environmental influences.

Phylogenetic tree

A diagram that shows the evolutionary relationships among various biological species.

Population

A group of individuals of the same species living in the same area.

Prokaryote

A single-celled organism that lacks a nucleus and other membrane-bound organelles.

Science

An organized way of gathering and analyzing evidence about the natural world.

Scientific theory

A well-tested explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment.

Taxonomic rank

The level in the hierarchy of classification, such as species, genus, family, order, class, phylum, kingdom, and domain.

Taxonomy

The science of naming, describing, and classifying organisms.