Animal Kingdom Practice Flashcards

A set of vocabulary flashcards covering the systems, classifications, and phyla of the animal kingdom from the lecture notes.

Cellular level of organisation

An arrangement of cells in loose aggregates, typical of sponges, where some division of labour occurs among individual cells.

Tissue level of organisation

An arrangement where cells performing the same function are organized into groups, as seen in coelenterates.

Organ level of organisation

A level exhibited by members of Platyhelminthes where tissues are grouped together to form specialised units for particular functions.

Organ system level of organisation

A pattern found in Annelids, Arthropods, Molluscs, Echinoderms, and Chordates where organs associate to form functional units concerned with specific physiological functions.

Incomplete digestive system

A digestive system featuring a single opening to the outside of the body that serves as both the mouth and the anus, characteristic of Platyhelminthes.

Complete digestive system

A digestive system that possesses two distinct openings: a mouth and an anus.

Open circulatory system

A type of system in which blood is pumped out of the heart and the cells and tissues are directly bathed in it.

Closed circulatory system

A system where blood is circulated through a series of vessels with varying diameters, specifically arteries, veins, and capillaries.

Radial symmetry

A body plan where any plane passing through the central axis of the body divides the organism into two identical halves, found in coelenterates, ctenophores, and echinoderms.

Bilateral symmetry

A body plan where the body can be divided into identical left and right halves in only one plane, exhibited by animals like annelids and arthropods.

Diploblastic

Animals in which cells are arranged in two embryonic layers: an external ectoderm and an internal endoderm, separated by an undifferentiated mesoglea.

Triploblastic

Animals in which the developing embryo has a third germinal layer, the mesoderm, located between the ectoderm and endoderm.

Coelom

The body cavity which is lined by mesoderm.

Coelomates

Animals possessing a true coelom, such as annelids, molluscs, arthropods, echinoderms, hemichordates, and chordates.

Pseudocoelom

A body cavity not lined by mesoderm, where the mesoderm is instead present as scattered pouches between the ectoderm and endoderm, characteristic of aschelminthes.

Acoelomates

Animals in which the body cavity is absent, such as platyhelminthes.

Metamerism

A phenomenon of segmentation where the body is externally and internally divided into segments with a serial repetition of at least some organs, as seen in earthworms.

Notochord

A mesodermally derived rod-like structure formed on the dorsal side during embryonic development in some animals.

Ostia

Minute pores in the body wall of sponges through which water enters the central cavity.

Spongocoel

The central cavity in sponges where water collected via ostia enters before leaving through the osculum.

Choanocytes

Specialized collar cells that line the spongocoel and the canals in members of phylum Porifera.

Cnidoblasts

Cells containing stinging capsules or nematocysts, present on the tentacles and body of cnidarians, used for anchorage, defense, and prey capture.

Metagenesis

The alternation of generations exhibited by some cnidarians, where polyps produce medusae asexually and medusae form polyps sexually.

Bioluminescence

The property of a living organism to emit light, which is well-marked in ctenophores.

Flame cells

Specialised cells in Platyhelminthes that assist with osmoregulation and excretion.

Radula

A file-like rasping organ used for feeding found in the mouth of molluscs.

Water vascular system

A distinctive feature of echinoderms that facilitates locomotion, capture and transport of food, and respiration.

Stomochord

A rudimentary structure in the collar region of hemichordates that is similar to a notochord.

Protochordates

A collective term for the subphyla Urochordata and Cephalochordata, which are exclusively marine.

Cyclostomata

A class of jawless vertebrates (Agnatha) that are ectoparasites on some fishes and have a sucking, circular mouth.

Chondrichthyes

Marine fishes with a cartilaginous endoskeleton, persistent notochord, and skin containing placoid scales.

Osteichthyes

A class of marine and fresh water fishes with a bony endoskeleton and an air bladder to regulate buoyancy.

Poikilothermous

Cold-blooded animals that lack the capacity to regulate their own body temperature.

Homoiothermous

Warm-blooded animals, such as birds and mammals, that are able to maintain a constant body temperature.

Pneumatic bones

Long bones that are hollow with air cavities, a characteristic feature of birds (Aves) to aid in flight.

Mammary glands

Unique milk-producing glands in mammals used to nourish the young.