invertebrates Flashcards
Porifera
Or sponges, are the simplest and oldest of the multicelled animals.
Cnidaria
Characterized by the specialized stinging structures in the tentacles surrounding the mouth.
Annelida
Also known as the ringed worms or segmented worms.
Hydroid
A hydrozoan polyp as distinguished from a hydrozoan jellyfish.
Jellyfish
Has a nearly transparent saucer-shaped body and extensible marginal tentacles studded with stinging cells.
Platyhelminthes
Are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates.
Nematoda
Free-living forms and disease-causing parasites, such as the hookworm and filaria.
Pinworms
A small nematoid worm that inhabits the rectum of the human host.
Tapeworms
Characterized by possessing a scolex with bothria that aid in attaching to their host, as well as a thin, long strobila body resembling a strip of tape or ribbon.
Bivalves
Having a shell consisting of two halves hinged together.
Gastropods
Usually with a univalve shell or none and a distinct head bearing sensory organs.
Coelomate
Have a body cavity called a coelom with a complete lining called peritoneum derived from mesoderm.
Acoelomate
Comprising the flatworms and nemerteans and characterized by bilateral symmetry and a digestive cavity
Radial Symmetry
Arrangement of parts of an organism around a single main axis.
Asymmetry
The body plan of many organisms exhibit symmetry.
