Biology Classification and Taxonomy

A comprehensive set of vocabulary flashcards covering the principles of taxonomy, classification hierarchies, the five kingdoms of life, and the specific characteristics of various plant and animal phyla.

Taxonomy

The study of biological classification.

Species

A group of organisms of common ancestry that closely resemble each other and are normally capable of interbreeding to produce fertile offspring; it is the basic unit of classification.

Homologies

Similarities between living things based on their lives, patterns, behaviors, environment, and evolution.

Artificial classification

A method that uses visible characteristics like colour, size, shape, or number of legs to classify organisms.

Natural classification

A method where organisms are grouped based on shared features from their ancestors, reflecting their evolutionary descent.

Taxon

Each individual group within the hierarchy of natural classification; the plural is taxa.

Binomial system

The naming system created by Linnaeus where organisms are identified by two names, the genus and the species name.

Eukaryotes

Organisms whose cells contain a distinct nuclei and membrane-bound organelles.

Prokaryotes

Organisms whose cells do not contain a distinct nucleus (DNA lies free in the cell) or membrane-bound organelles.

Kingdom Eubacteria (Prokaryotae)

Unicellular organisms that possess a cell wall, lack a true nucleus, and lack membrane-bound organelles like mitochondria.

Kingdom Protoctista (Protist)

Mostly unicellular organisms with a true nucleus; includes animal-like protozoans and plant-like algae.

Kingdom Fungi

Mostly multicellular organisms with a body (mycelium) composed of hyphae, cell walls containing chitin, and that lack chlorophyll.

Kingdom Plantae

Multicellular, stationary organisms with cell walls made of cellulose and chlorophyll; they are autotrophic.

Bryophytes

A plant phylum having simple stems, leaves, and root-like filaments called rhizoids; they produce spores for reproduction.

Pteridophytes (Ferns)

Plants with proper roots, stems, and leaves called fronds that produce spores on the underside for reproduction.

Gymnosperms (Conifers)

Plants with proper roots and stems, needle-shaped leaves, and seeds produced inside cones.

Angiosperms (Flowering plants)

Plants with proper roots, stems, and leaves that produce seeds inside fruits that develop from the ovaries of flowers.

Monocotyledons

Flowering plants with leaves containing parallel veins, seeds with one cotyledon, and flower parts in multiples of three.

Dicotyledons

Flowering plants with leaves having a network of veins, seeds with two cotyledons, and flower parts in multiples of four or five.

Kingdom Animalia

Multicellular, heterotrophic organisms whose cells lack cell walls and chlorophyll; most are capable of locomotion.

Porifera

Stationary organisms (sponges) that lack tissues and organs, featuring a body with a single cavity and many pores.

Cnidaria (Coelenterates)

Organisms with radial symmetry, a gut with only one opening (the mouth), and a ring of tentacles with stinging cells.

Platyhelminthes

Flatworms with a long, flat, unsegmented body.

Nematodes

Roundworms with an elongated, round, unsegmented body with pointed ends.

Annelids

Segmented worms with an elongated body that is round in cross-section.

Arthropods

Organisms with a waterproof exoskeleton made of chitin, a segmented body, and several pairs of jointed legs.

Crustaceans

Arthropods with two pairs of antennae, usually five or seven pairs of legs, and a body divided into a cephalothorax and abdomen.

Arachnids

Arthropods with no antennae, mouthparts with pincers, and four pairs of legs.

Insects

Arthropods with one pair of antennae, three pairs of legs, a pair of compound eyes, and usually two pairs of wings.

Myriapods

Arthropods with one pair of antennae and many pairs of legs; the body is elongated and divided into many segments.

Molluscs

Organisms with a soft, moist, unsegmented body and a muscular foot; many possess shells.

Echinoderms

Organisms with a body based on a radial pattern of five parts, containing calcium carbonate plates and tube feet for movement.

Chordates/vertebrates

Organisms with a notochord, a dorsal nerve cord, and usually an internal skeleton of bone and cartilage.

Pisces (Fish)

Poikilothermic chordates with waterproof skin covered in scales, gills for breathing, and fins for swimming.

Amphibians

Poikilothermic organisms with soft, moist, non-waterproof skin; they lay eggs in water and adults usually have lungs.

Reptiles

Poikilothermic organisms with dry, waterproof skin with scales that lay eggs with a rubbery shell on land.

Aves (Birds)

Homeothermic organisms with skin covered in feathers, a beak, and forelimbs modified into wings; they lay eggs with a hard shell.

Mammals

Homeothermic organisms with skin containing hair and sweat glands; young develop inside the mother and feed on milk.

Poikilothermic

The condition of being cold-blooded.

Homeothermic

The condition of being warm-blooded.

Dichotomous key

An identification tool that uses two opposing statements called couplets to categorize organisms.