Invertebrates Flashcards
Vertebrates
An animal that has a backbone.
Invertebrates
An animal that does not have a backbone
Consumer
An organism that eats other organisms or organic matter.
Ganglion
A mass of nerve cells.
Gut
The digestive tract.
Coelom
A body cavity that contains the internal organs.
Bilateral Symmetry
The property or being divisible into symmetrical halves on either side of a unique plane.
Radical Symmetry
Symmetry around a central axis, as in a starfish or a tulip flower.
Asymmetry
Lack of equality or equivalence between parts or aspects of something; lack of symmetry.
Sponges
A primitive sedentary aquatic invertebrate with a soft porous body that is typically supported by a framework of fibers or calcareous or glassy spicules. Sponges draw in a current of water to extract nutrients and oxygen.
Cnidarians
An aquatic invertebrate animal of the phylum Cnidaria, which compromises the coelenterates.
Flatworms
A worm of a phylum that includes the planarians together with the parasitic flukes and tapeworms. They are distinguished by having a simple flattened body that lacks blood vessels, and a digestive tract that, if present, has a single opening.
Roundworms
A nematode, especially a parasite one found in the intestines of mammals.
Mollusks
An invertebrate of a large phylum that includes snails, slugs, mussels, and octopuses. They have a soft, unsegmented body and live in aquatic or damp habitats, and most kinds have an external calcareous shell.
Open circulatory system
A circulatory system in which the circulatory fluid is not contained entirely within vessels; a heart pumps fluid through vessels that empty into spaces called sinuses.
Closed circulatory system
A circulatory system in which the heart circulates blood through a network of vessels that form a closed loop; the blood does not leave the blood vessels, and materials diffuse across the walls of the vessels.
Annelid worms
Known as the ringed worms or segmented worms, are a large phylum, with over 17,000 extant species including rag worms, earthworms, and leeches.
Exoskeleton
A hard, external, supporting structure.
Compound eye
An eye composed of many light detectors.
Antenna
either of a pair of long, thin sensory appendages on the heads of insects, crustaceans, and some other arthropods.
Metamorphosis
A phase in the life cycle of many animals during which a rapid change from the immature form of an organism to the adult form takes place.
Endoskeleton
An internal skeleton made of bone and cartilage.
Water vascular system
A system of canals filled with a watery fluid that circulates throughout the body of an echinoderm.
