Biology Chapter 4: Animal Kingdom Flashcards

A comprehensive set of vocabulary flashcards covering the basis of classification, the 11 phyla, and the classes of vertebrates as described in the Chapter 4 Animal Kingdom lecture notes.

Kingdom Animalia

Includes multicellular and heterotrophic organisms that lack a cell wall and chlorophyll.

Cellular level of organization

A level of organization where cells are arranged as loose cell aggregates, as seen in Phylum Porifera.

Tissue level of organization

A level of organization where cells are arranged into tissues, as seen in Cnidarians and Ctenophores.

Organ level of organization

A level of organization where tissues are arranged into organs, found in higher animals from Platyhelminthes to Chordates.

Organ system level of organization

A level of organization where organs are associated into systems, each performing a specific physiological function.

Incomplete digestive system

A digestive system with a single opening that acts as both a mouth and an anus, observed in Cnidaria and Platyhelminthes.

Complete digestive system

A digestive system with two separate openings, a mouth and an anus.

Radial symmetry

A type of symmetry where the body can be divided into two equal halves in any vertical plane along the central (oral-aboral) axis.

Bilateral symmetry

A type of symmetry where the body can be divided into identical right and left halves in only one plane.

Diploblastic animals

Animals with two germ layers: an outer ectoderm and an inner endoderm, with an undifferentiated mesoglea in between.

Triploblastic animals

Animals with three germ layers: an outer ectoderm, a middle mesoderm, and an inner endoderm.

Coelom

A body cavity lined by mesoderm situated between the body wall and the gut wall.

Acoelomate

Animals that lack a coelom; the space between the body wall and digestive cavity is filled with matrix (parenchyma).

Pseudocoelomate

Animals with a 'false coelom' where the body cavity is not lined by mesoderm, but instead has mesoderm as scattered pouches.

Coelomate

Animals possessing a true coelom that arises from the mesoderm and is lined by a peritoneal layer.

Metamerism

A phenomenon where the body or organs are divided externally and internally into repeated segments called metameres.

Notochord

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

Hermaphrodite (Monoecious)

An individual that possesses both male and female sex organs.

Choanocytes (collar cells)

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

Cnidoblasts (Cnidocytes)

Stinging cells on tentacles and the body of Cnidarians containing a poison-filled capsule called a nematocyst.

Metagenesis

The phenomenon of alternation of generation where polyps produce medusae asexually and medusae form polyps sexually, as seen in Obelia.

Bioluminescence

The property of a living organism to emit light from its body, a unique feature of Phylum Ctenophora.

Flame cells (protonephridia)

Specialized cells used for excretion and osmo-regulation in Phylum Platyhelminthes.

Sexual dimorphism

Morphological differences between males and females of the same species, such as female Aschelminthes being longer than males.

Radula

A file-like rasping organ used for feeding, located in the mouth of most molluscs.

Water vascular (ambulacral) system

A system in Echinoderms where sea water enters through a madreporite to facilitate locomotion, respiration, and food transport.

Cyclostomata

A class of vertebrates that are ectoparasites on fishes, featuring a sucking circular mouth without jaws and $6-15$ pairs of gill slits.

Poikilotherms

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

Homoiotherms

Warm-blooded animals that have the ability to maintain a constant body temperature.

Pneumatic bones

Long, hollow bones found in birds (Class Aves) that assist in flight by reducing body weight.