Animal Kingdom – Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering key terms, phyla, structures and physiological concepts from the Animal Kingdom lecture.

Animal Classification

Grouping of animals based on common fundamental features such as body organisation, symmetry, coelom, etc.

Cellular Level of Organisation

Body made of loosely arranged cells with minimal division of labour, e.g., sponges.

Tissue Level of Organisation

Similar cells form tissues; seen in coelenterates and ctenophores.

Organ Level of Organisation

Tissues combine to form organs; first appears in Platyhelminthes.

Organ-System Level of Organisation

Organs work together as systems; characteristic of Annelids to Chordates.

Incomplete Digestive System

Single opening serving as both mouth and anus.

Complete Digestive System

Digestive tract with separate mouth and anus.

Open Circulatory System

Blood pumped into body cavities bathing organs directly.

Closed Circulatory System

Blood confined to vessels such as arteries, veins and capillaries.

Asymmetry

No plane can divide the body into equal halves; typical of most sponges.

Radial Symmetry

Any plane through central axis yields equal halves; e.g., cnidarians, ctenophores, adult echinoderms.

Bilateral Symmetry

Single plane divides body into left and right halves; e.g., annelids, arthropods.

Diploblastic

Body derived from two germ layers – ectoderm and endoderm, with mesoglea in between.

Triploblastic

Body derived from three germ layers – ectoderm, mesoderm and endoderm.

Coelom

Mesoderm-lined body cavity between gut and body wall.

Coelomate

Animal possessing a true coelom, e.g., annelids, molluscs.

Pseudocoelomate

Body cavity not fully lined by mesoderm; e.g., aschelminthes.

Acoelomate

No body cavity; e.g., platyhelminthes.

Metamerism

Serial repetition of body segments both internally and externally, as in earthworms.

Notochord

Dorsal rod-like mesodermal structure present in chordates during development.

Phylum Porifera

Aquatic, mostly marine sponges with cellular organisation and canal system.

Ostia

Minute pores in sponge body wall through which water enters.

Spongocoel

Central cavity of a sponge into which water flows.

Osculum

Large opening through which water exits a sponge.

Choanocyte

Flagellated collar cell lining canals of sponges, aiding water flow and food capture.

Hermaphrodite (Sponges)

Single individual produces both eggs and sperm.

Cnidoblast/Cnidocyte

Stinging cell of cnidarians containing a nematocyst.

Nematocyst

Capsule within cnidocyte that ejects a coiled thread for defense or prey capture.

Polyp

Sessile, cylindrical cnidarian body form (e.g., Hydra).

Medusa

Free-swimming, umbrella-shaped cnidarian form (e.g., jellyfish).

Metagenesis

Alternation between polyp and medusa generations in some cnidarians.

Phylum Ctenophora

Marine ‘comb jellies’ bearing eight rows of ciliated comb plates.

Comb Plates

Ciliated bands used for locomotion in ctenophores.

Bioluminescence

Ability of living organisms such as ctenophores to emit light.

Phylum Platyhelminthes

Dorsoventrally flattened acoelomate worms; many are parasitic.

Flame Cells

Specialised excretory and osmoregulatory cells in flatworms.

Phylum Aschelminthes

Roundworms; pseudocoelomate, complete alimentary canal.

Dioecious

Male and female sexes are separate individuals.

Excretory Pore (Roundworms)

Opening through which wastes exit via an excretory tube.

Phylum Annelida

Segmented, coelomate worms such as earthworms and leeches.

Parapodia

Paired lateral appendages for swimming in some marine annelids.

Nephridium

Excretory and osmoregulatory organ of annelids.

Phylum Arthropoda

Largest animal phylum, characterised by jointed appendages and chitinous exoskeleton.

Malpighian Tubules

Excretory organs of most terrestrial arthropods.

Compound Eye

Multifaceted visual organ of many arthropods providing a broad field of view.

Phylum Mollusca

Soft-bodied coelomates usually with calcareous shell and muscular foot.

Mantle

Soft fold of skin secreting shell and forming mantle cavity in molluscs.

Radula

File-like rasping organ in molluscs used for feeding.

Visceral Hump

Dorsal mass containing internal organs of a mollusc.

Phylum Echinodermata

Marine animals with spiny skin and water vascular system.

Calcareous Ossicles

Small plates forming the endoskeleton of echinoderms.

Water Vascular System

Network of canals in echinoderms used for locomotion and respiration.

Phylum Hemichordata

Worm-like marine animals with a stomochord and tripartite body.

Stomochord

Rudimentary, notochord-like structure in hemichordates.

Proboscis (Hemichordata)

Anterior body region used for burrowing and feeding.

Phylum Chordata

Animals possessing notochord, dorsal hollow nerve cord and pharyngeal gill slits.

Dorsal Hollow Nerve Cord

Tube-like nervous system running along the back of chordates.

Post-Anal Tail

Tail extending beyond the anus in chordates.

Protochordates

Urochordata and Cephalochordata; chordates without vertebral column.

Urochordata

Subphylum where notochord is present only in larval tail.

Cephalochordata

Subphylum with notochord extending from head to tail throughout life.

Vertebral Column

Bony or cartilaginous backbone replacing notochord in adult vertebrates.

Cyclostomata

Jawless, ectoparasitic vertebrates like lampreys and hagfishes.

Chondrichthyes

Cartilaginous fishes with placoid scales and ventral mouth.

Placoid Scales

Tooth-like dermal scales of cartilaginous fishes.

Claspers

Copulatory organs on pelvic fins of male cartilaginous fishes.

Osteichthyes

Bony fishes possessing operculum and swim bladder.

Operculum

Bony gill cover in bony fishes.

Swim (Air) Bladder

Gas-filled sac in bony fishes regulating buoyancy.

Amphibia

Tetrapods able to live in water and on land; moist skin and three-chambered heart.

Cloaca

Common chamber for digestive, urinary and reproductive tracts in amphibians (and others).

Reptilia

Cold-blooded tetrapods with dry, cornified skin and mostly three-chambered heart.

Scute

Keratinised scale covering reptile skin.

Aves

Warm-blooded vertebrates with feathers, beak and pneumatic bones.

Pneumatic Bones

Hollow, air-filled bones of birds, reducing weight for flight.

Crop

Storage chamber in bird digestive tract before the stomach.

Gizzard

Muscular grinding organ of bird stomach.

Air Sacs

Thin-walled sacs connected to lungs of birds, aiding efficient respiration.

Mammalia

Warm-blooded vertebrates with hair, mammary glands and diaphragm.

Mammary Glands

Milk-producing glands nourishing mammalian young.

Pinnae

External ear flaps of mammals aiding sound collection.

Viviparous

Bearing live young after internal development.

Poikilothermous

Cold-blooded; body temperature varies with environment.

Homoiothermous

Warm-blooded; capable of maintaining constant body temperature.