Section 26 Vocab Flashcards
Cnidocyte
Stinging cell of cnidarians; used for defense and to capture prey
Nematocyst
Stinging structure within each cnidocyte of a cnidarian that is used to poison or kill prey
Polyp
Usually sessile stage of the life cycle of A cnidarian that has a cylindrical body with armoire tentacles
Medusa
Motile stage of life cycle of a cnidarian that has a bell shaped body
Gastrovascular cavity
Digestive chamber with a single opening, in which cnidarians, flatworms, and echinoderms digest food
Nerve net
Loosely organized network of nerve cells that together allow cnidarians to detect stimuli
Hydrostatic skeleton
Layers of circular longitudinal muscles, together with the water in the gastrovascular cavity, that enable movement
External fertilization
Process in which eggs are fertilized outside the females body
Invertebrate
Animal that does not have a backbone or vertebral column
Vertebrate
Animal that has a vertebral column, or backbone
Feedback inhibition
Process in which the product or result stops or limits the process
Blastula
Hollow ball of cells formed when a zygote undergoes a series of divisons
Protostome
Animal whose mouth is formed from its blastopore
Deuterostome
Animal whose anus is formed from the blastopore of a Blastula
Anus
Opening through which wastes leave the digestive tract
Endoderm
Innermost germ layers of most animals; develops into the linings of the digestive tract and much of the respiratory system
Ectoderm
Outermost germ layer of most animals; gives rise to outer layer of the skin, sense organs, and nerves
Radial symmetry
Body play in which body parts repeat around the center of the body; characteristic of a sea anemones and sea stars
Bilateral symmetry
Body plan in which only a single, imaginary line can divide the body into two equal halves; characteristics of worms, arthropods, and chordates
Cephalization
Concentration of sense organs and nerve cells at the front of an animals body
Choanocyte
Specialized cell in sponges that use a flagellum to move a steady current of water through the sponge
Osculum
Large hole at the top of the sponge through which water leaves the sponge
Spicule
Spike shaped structure that makes up the skeletons of harder sponges; made of either calcium carbonate or silica
Archaeocyte
Specialized cell in a sponge that makes spicules
Internal fertilization
Process in which eggs are fertilized inside the females body
Larva
Immature stage of an organism that looks different from the adult form
Gemmule
Group of archaeocytes surrounded by a tough layer of spicules; produced by some sponges
