- acoelomate
- without a body cavity
- Actinopterygii
- ray-finned fishes
- amniote
- a clade of animals that possesses an amniotic egg; includes reptiles (including birds) and mammals
- amoebocyte
- an amoeba-like cell of sponges whose functions include distribution of nutrients to other cells in the sponge
- Amphibia
- frogs, salamanders, and caecilians
- ampulla of Lorenzini
- a sensory organ that allows sharks to detect electromagnetic fields produced by living things
- Annelida
- a phylum of worm-like animals with metamerism
- anthropoids
- a clade consisting of monkeys, apes, and humans
- Anura
- frogs
- Apoda
- caecilians
- Arthropoda
- a phylum of Ecdysozoa with jointed appendages and segmented bodies
- asymmetrical
- having no plane of symmetry
- bilateral symmetry
- a type of symmetry in which there is only one plane of symmetry that creates two mirror-image sides
- body plan
- the shape and symmetry of an organism
- brachiation
- swinging through trees
- budding
- a form of asexual reproduction that occurs through the growth of a new organism as a branch on an adult organism that breaks off and becomes independent; found in plants, sponges, cnidarians, and some other invertebrates
- caecilian
- a legless amphibian that belongs to clade Apoda
- Cephalochordata
- a chordate clade whose members possess a notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail in the adult stage
- cephalothorax
- a fused head and thorax
- chaeta
- a chitinous projection from the cuticle found in annelids
- chelicerae
- a modified first pair of appendages in subphylum Chelicerata
- chitin
- a tough nitrogen-containing polysaccharide found in the cuticles of arthropods and the cell walls of fungi
- choanocyte
- a cell type unique to sponges with a flagellum surrounded by a collar used to maintain water flow through the sponge, and capture and digest food particles
- Chondrichthyes
- jawed fishes with paired fins and a skeleton made of cartilage
- Chordata
- a phylum of animals distinguished by their possession of a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail at some point during their development
- clitellum
- a specialized band of fused segments in some annelids, which aids in reproduction
- Cnidaria
- a phylum of animals that are diploblastic and have radial symmetry and stinging cells
- cnidocyte
- a specialized stinging cell found in Cnidaria
- coelom
- a lined body cavity derived from mesodermal embryonic tissue
- complete digestive system
- a digestive system that opens at one end, the mouth, and exits at the other end, the anus, and through which food normally moves in one direction
- craniate
- a proposed clade of chordates that includes all groups except the tunicates and lancelets
- Crocodilia
- crocodiles and alligators
- ctenidia
- specialized gills in mollusks
- cutaneous respiration
- gas exchange through the skin
- deuterostome
- describing an animal in which the blastopore develops into the anus, with the second opening developing into the mouth
- dioecious
- having separate male and female sexes
- diphyodont
- refers to the possession of two sets of teeth in a lifetime
- diploblast
- an animal that develops from two embryonic germ layers
- dorsal hollow nerve cord
- a hollow, tubular structure derived from ectoderm, which is located dorsal to the notochord in chordates
- down feather
- feather specialized for insulation
- Echinodermata
- a phylum of deuterostomes with spiny skin; exclusively marine organisms
- epidermis
- the layer of cells that lines the outer surface of an animal
- eucoelomate
- describing animals with a body cavity completely lined with mesodermal tissue
- eutherian mammal
- a mammal with a complex placenta, which connects a fetus to the mother; sometimes called placental mammals
- extracellular digestion
- a form of digestion, the breakdown of food, which occurs outside of cells with the aid of enzymes released by cells
- fragmentation
- a form of asexual reproduction in which a portion of the body of an organism breaks off and develops into a living independent organism; found in plants, sponges, and some other invertebrates
- frog
- a tail-less amphibian that belongs to clade Anura
- gastrodermis
- the layer of cells that lines the gastrovascular cavity of cnidarians
- gastrovascular cavity
- the central cavity bounded by the gastrodermis in cnidarians
- gemmule
- a structure produced by asexual reproduction in freshwater sponges that is able to survive harsh conditions
- germ layer
- a collection of cells formed during embryogenesis that will give rise to future body tissues
- gnathostome
- a jawed fish
- hagfish
- an eel-like jawless fish that lives on the ocean floor and is a scavenger
- hemocoel
- the internal body cavity seen in arthropods
- heterodont teeth
- different types of teeth modified by different purposes
- intracellular digestion
- the digestion of matter brought into a cell by phagocytosis
- lamprey
- a jawless fish characterized by a toothed, funnel-like, sucking mouth
- lancelet
- a member of Cephalochordata; named for its blade-like shape
- lateral line
- the sense organ that runs the length of a fish’s body, used to detect vibration in the water
- Lophotrochozoa
- a clade of invertebrate organisms that is a sister group to the Ecdysozoa
- madreporite
- a pore for regulating entry and exit of water into the water vascular system
- mammal
- one of the groups of endothermic vertebrates that possess hair and mammary glands
- mammary gland
- in female mammals, a gland that produces milk for newborns
- mantle
- a specialized epidermis that encloses all visceral organs and secretes shells in mollusks
- marsupial
- one of the groups of mammals that includes the kangaroo, koala, bandicoot, Tasmanian devil, and several other species; young develop within a pouch
- medusa
- a free-floating cnidarian body plan with a mouth on the underside and tentacles hanging down from a bell
- mesoglea
- the non-living, gel-like matrix present in between ectoderm and endoderm in cnidarians
- mesohyl
- the collagen-like gel containing suspended cells that perform various functions in sponges
- metamerism
- having a series of body structures that are similar internally and externally, such as segments
- Mollusca
- a phylum of protostomes with soft bodies and no segmentation
- monoecious
- having both sexes in one body, hermaphroditic
- monotreme
- an egg-laying mammal
- Myxini
- hagfishes
- nacre
- a calcareous secretion produced by bivalve mollusks to line the inner side of shells as well as to coat foreign particulate matter
- nematocyst
- the harpoon-like organelle within a cnidocyte with a pointed projectile and poison to stun and entangle prey
- Nematoda
- a phylum of worms in Ecdysozoa commonly called roundworms containing both free-living and parasitic forms
- notochord
- a flexible, rod-shaped structure that is found in the embryonic stage of all chordates and in the adult stage of some chordates
- osculum
- the large opening in a sponge body through which water leaves
- Osteichthyes
- bony fishes
- ostracoderm
- one of the earliest jawless fishes covered in bone
- Petromyzontidae
- the clade of lampreys
- pharyngeal slit
- an opening in the pharynx
- pneumatic bone
- an air-filled bone
- polyp
- the stalk-like, sessile life form of a cnidarians with mouth and tentacles facing upward, usually sessile but may be able to glide along a surface
- Porifera
- a phylum of animals with no true tissues, but a porous body with a rudimentary endoskeleton
- post-anal tail
- a muscular, posterior elongation of the body extending beyond the anus in chordates
- Primates
- includes lemurs, tarsiers, monkeys, apes, and humans
- prosimians
- a group of primates that includes bush babies of Africa, lemurs of Madagascar, and lorises, pottos, and tarsiers of southeast Asia
- protostome
- describing an animal in which the mouth develops first during embryogenesis and a second opening developing into the anus
- pseudocoelomate
- an animal with a coelom that is not completely lined with tissues derived from the mesoderm as in eucoelomate animals
- radial symmetry
- a type of symmetry with multiple planes of symmetry all cross at an axis through the center of the organism
- radula
- a tongue-like scraping organ with chitinous ornamentation found in most mollusks
- salamander
- a tailed amphibian that belongs to the clade Urodela
- Sarcopterygii
- lobe-finned fishes
- sebaceous gland
- in mammals, a skin gland that produce a lipid mixture called sebum
- Sphenodontia
- the reptilian clade that includes the tuataras
- spicule
- a short sliver or spike-like structure, in sponges, they are formed of silicon dioxide, calcium carbonate, or protein, and are found in the mesohyl
- spiracle
- a respiratory openings in insects that allow air into the tracheae
- spongocoel
- the central cavity within the body of some sponges
- Squamata
- the reptilian clade of lizards and snakes
- stereoscopic vision
- two overlapping fields of vision from the eyes that produces depth perception
- sudoriferous gland
- a gland in mammals that produces sweat and scent molecules
- swim bladder
- in fishes, a gas filled organ that helps to control the buoyancy of the fish
- tadpole
- the larval stage of a frog
- Testudines
- turtles
- tetrapod
- a four-footed animal; includes amphibians, reptiles, birds, and mammals
- trachea
- in some arthropods, such as insects, a respiratory tube that conducts air from the spiracles to the tissues
- triploblast
- an animal that develops from three germ layers
- tunicate
- a sessile chordate that is a member of Urochordata
- Urochordata
- the clade composed of the tunicates
- Urodela
- salamanders
- vertebral column
- a series of separate bones that surround the spinal cord in vertebrates
- water vascular system
- a system in echinoderms in which water is the circulatory fluid