Classification of Life

Prokaryotic

Cells that lack a nucleus and membrane-bound organelles and are unicellular, such as bacteria and archaea

Eukaryotic

Organisms with complex cells that contain a nucleus and membrane-bound organelles

Unicellular

single-celled organisms that can exist independently or as part of a colony

Multicellular

Organisms composed of multiple cells that work together, such as plants and animals

Colonial

Organisms that live in groups of interconnected individual cells, functioning together as a single entity while still maintaining some independence

Autotrophic

Organisms that produce their own food using sunlight (photosynthesis) or inorganic compounds (chemosynthesis), such as plants and some bacteria

Heterotrophic

Organisms that obtain energy by consuming other living things or organic matter

Mixotrophic

Organisms that can obtain energy through both autotrophic and heterotrophic means

Peptidoglycan

A polymer that makes up the cell wall of many bacteria, providing structural support and protection

Chitin

A long-chain polymer that provides structural support in the cell walls of fungi and the exoskeletons of arthropods

Cellulose

A polysaccharide that forms the primary structural component of plant cell walls, providing rigidity and strength

Photosynthesis

The process by which green plants, algae, and some bacteria convert light energy into chemical energy, using carbon dioxide and water to produce glucose and oxygen

Chemosynthesis

The process by which certain organisms, such as bacteria, use the energy released from chemical reactions (often involving hydrogen sulfide, methane, or ammonia) to convert carbon dioxide into organic molecules (food)

Thermophiles

Organisms that thrive at high temperatures, typically found in geothermal environments like hot springs

Halophiles

Organisms that thrive in high-salinity environments, such as salt lakes and salt mines

Acidophiles

Organisms that thrive in highly acidic environments, often found in places like acid mine drainage and sulfuric hot springs

Psychrophiles

Organisms that thrive in extremely cold environments, such as polar regions and deep ocean waters

Porifera

A phylum of simple multicellular animals, commonly known as sponges, that live mainly in aquatic environments

Cnidaria

A phylum of animals known for their stinging cells, including jellyfish, corals, and sea anemones. They exhibit radial symmetry and have two main body forms: polyp and medusa

Platyhelminthes

A phylum of flatworms that are soft-bodied and unsegmented, including both free-living and parasitic species

Nematoda

A phylum of roundworms characterized by their elongated, cylindrical bodies, and are found in a variety of environments, including soil and aquatic ecosystems

Annelida

A phylum of segmented worms, including earthworms and leeches, characterized by their segmented bodies and a true coelom

Mollusca

A diverse phylum of invertebrates, including snails, clams, and octopuses, characterized by a soft body, often with a hard shell, and a muscular foot

Arthropoda

A phylum of invertebrate animals that includes insects, arachnids, and crustaceans, characterized by their exoskeleton, segmented bodies, and jointed appendages

Echinodermata

A phylum of marine invertebrates, including starfish, sea urchins, and sea cucumbers, characterized by radial symmetry, a calcareous endoskeleton, and a water vascular system

Chordata

A phylum that includes animals with a notochord, such as vertebrates, which have a backbone, along with tunicates and lancelets

Domain

The highest taxonomic rank in the biological classification system, encompassing all living organisms. There are three recognized domains: Bacteria, Archaea, and Eukarya

Kingdom

a taxonomic rank used in biological classification, which is above phylum and below domain

Phylum

A taxonomic rank below kingdom and above class, grouping together organisms that share a set of characteristics, such as body structure or embryonic development

Class

A taxonomic rank below phylum and above order, grouping together organisms with similar characteristics and evolutionary traits

Order

A taxonomic rank below class and above family, used to group together organisms that share common characteristics

Family

A taxonomic rank below order and above genus, classifying groups of related organisms that share more specific characteristics

Genus

A taxonomic rank below family and above species, classifying groups of closely related species that share common characteristics

Species

The most specific taxonomic rank, classifying individual organisms that can interbreed and produce fertile offspring

Kingdom Archaebacteria

A high-level taxonomic category representing a group of prokaryotic microorganisms that are distinct from bacteria. They often thrive in extreme environments

Kingdom Eubacteria

A major taxonomic rank that includes prokaryotic organisms known as bacteria, characterized by their ability to thrive in various environments, including extreme conditions

Kingdom Protista

A diverse taxonomic group that includes unicellular and simple multicellular eukaryotic organisms, such as protozoa, algae, and slime molds

Kingdom Animalia

A major kingdom that encompasses multicellular eukaryotic organisms, characterized by their ability to consume organic material, breathe oxygen, and reproduce sexually or asexually

Kingdom Plantae

The kingdom that comprises multicellular, photosynthetic organisms known as plants, which play a vital role in ecosystems as producers

Kingdom Fungi

A kingdom that includes eukaryotic organisms such as molds, yeast, and mushrooms, characterized by their cell walls made of chitin and their role as decomposers in ecosystems