Classification

biodiversity

the variety of life in the world, encompassing the different species, ecosystems, and genetic variation within species.

taxonomy

the science of classifying and naming organisms based on shared characteristics and evolutionary relationships.

taxon

a group of one or more populations of organisms that share certain characteristics and are categorized within a classification system.

kingdom

the second highest taxonomic rank, below domain, that groups together all forms of life sharing fundamental characteristics, such as plants, animals, fungi, and bacteria.

domain

the highest taxonomic rank that classifies all living organisms into broad categories based on fundamental differences, including bacteria, archaea, and eukaryotes.

phylum

a taxonomic rank that groups together organisms sharing a basic structural organization and key features, encompassing several classes within it.

division

a taxonomic category used primarily in botanical classification, equivalent to phylum, that groups plants based on similar characteristics.

class

a taxonomic rank that groups together organisms within a phylum that share common characteristics and further divides them into orders.

order

a taxonomic rank that categorizes organisms within a class based on shared characteristics, further dividing them into families.

family

a taxonomic rank that groups together related genera sharing common characteristics, facilitating further classification into species.

genus

a taxonomic rank that groups together species that are closely related and share a common ancestor, serving as a level of classification between family and species.

species

the basic unit of classification, usually defined as a group of organisms capable of interbreeding and producing fertile offspring.

binomial nomenclature

a formal system of naming species using two Latin names, the first indicating the genus and the second the species.

systematics

the scientific study of the diversity of organisms and their evolutionary relationships, often involving taxonomy and phylogenetics.

phylogenetics

the branch of systematics that focuses on the evolutionary history and relationships among species based on their genetic and morphological characteristics.

phylogenetic diagram

a graphical representation of the evolutionary relationships among various biological species based on their evolutionary history.

cladistics

a method of classification based on common ancestry and the branching patterns of evolution.

shared characteristic

a trait or feature that is common to two or more taxa and indicates their evolutionary relationship.

derived characteristic

a trait that evolved in a particular lineage and is not found in more distant ancestors, used to assess evolutionary relationships.

clade

a group of organisms that includes an ancestor and all its descendants, representing a single branch on the tree of life.

cladogram

a diagram that shows the evolutionary relationships among various biological species based on shared derived characteristics.

Bacteria

single-celled microorganisms that are prokaryotic and can be found in various environments. They play essential roles in processes such as decomposition and nitrogen fixation.

Archaea

single-celled microorganisms similar to bacteria but with distinct genetic and biochemical characteristics, often found in extreme environments.

Eukarya

organisms composed of eukaryotic cells, which contain a nucleus and membrane-bound organelles, including animals, plants, fungi, and protists.

Eubacteria

a major group of bacteria characterized by their simple cell structure and the presence of peptidoglycan in their cell walls, commonly found in various environments.

Archaebacteria

a group of microorganisms formerly considered bacteria but more closely related to eukaryotes, often found in extreme environments.

Protista

a diverse group of eukaryotic organisms, including unicellular and simple multicellular forms, such as algae and protozoa, that do not fit into the other kingdoms.

Fungi

a kingdom of eukaryotic organisms that includes yeasts, molds, and mushrooms, which are heterotrophic and absorb nutrients from their environment.

Plantae

a kingdom of eukaryotic organisms that are primarily autotrophic, using photosynthesis to produce their own food, and include flowering plants, conifers, and ferns.

Animalia

a kingdom of eukaryotic organisms that are primarily heterotrophic, consuming organic material for energy, and include various species ranging from sponges to mammals.

subspecies

a taxonomic category ranking below species, used to classify populations of organisms that exhibit distinct characteristics yet can interbreed with others of the same species.

prokaryotic cell

eukaryotic cell

prokaryotic cell

a type of cell that lacks a true nucleus and other membrane-bound organelles. Its genetic material (DNA) is located in a region called the nucleoid, and it typically has a simpler structure than eukaryotic cells. Examples include Bacteria and Archaea.

eukaryotic cell

eukaryotic cell

a type of cell that possesses a true nucleus enclosed within a nuclear envelope, and various other membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Its genetic material (DNA) is organized into chromosomes within the nucleus. Eukaryotic cells are typically larger and more complex than prokaryotic cells. Examples include cells of animals, plants, fungi, and protists.