Exam 2 Vocab 2 Flashcards
Benthic
Living at the bottom of aquatic environments
Sessile
Permanently attached substrate
Diploblasts
Animals whose embryos have two germ layers (ecto and endoderm)
Triploblasts
Animals whose embryos have 3 germ layers (end, ectoderm and mesoderm)
Chephalization
Evolution of a head where structures for feeding, sensing the environment and processing info are concentrated
Coelom
enclosed fliud-filled body cavity between the tubes
Segmentation
presence of repeated body structures
Visceral mass
One of the 3 main parts of the mollusk body; contains most of the internal organs and external gills
trochophore
a larva with a ring of cilia around its middle that is found in some lopotrochozoans
Worm
an animal with a long, thin, tubelike body lacking limbs
Roundworms
members of the nematoda. Distinguished by an unsegmented body with a pseudocoelom and no appendages. Ecdysozoan
Rotifer
Rotifera. Distinguished by a cluster of cilia,called corona, used in suspension feeding in marine and freshwater environments. lophotrochozoan
Molting
Method of body growth by ecdysozons, that involves the shedding of an external protective cuticle or skeleton, expansion of the soft body, and growth of a new external layer.
Lophophore
a specialized feeding structure found in some lophotrochozoans and used in suspension (filter) feeding
Flatworms
members of the phylum Playhelminthes. Distinguished by a broad, flat, unsegmented body that lacks a coelom. Flatworms belong to the lophotrochozoan branch of protostomes.
Arthropods
members of phylum Arthropoda. Distinguished by a segmented body; a hard, jointed exoskeleton; paired, jointed appendages; and an extensive body cavity called a hemocoel. Arthropods belong to the ecdysozoan branch of the protostomes
Annelids
members of the phylum Annelia (segmented worms). Distinguished by a segmented body and a coelom that functions as a hydrostatic skeleton. Annelids belong to the lophotrochozoan branch of the protostomes
Bilateral symmetry
an animal body pattern in which one plane of symmetry divides the body into a left side and a right side. Typically, the body is a long and narrow, with a distinct head end and tail end.
Brain
a large mass of neurons, located in the head region of an animal, that is involved in information processing; may also be called the cerebral ganglion
Acoelomate
a bilaterian animal that lacks an internal body cavity (coelom).
CNS
large numbers of neurons aggregated into clusters called ganglia in bilaterian animals. In vertebrates, the central nervous system consists of the brain and spinal cord.
Choanocyte
a specialized, flagellated feeding cell found in choanoflagellates (protists that are the closest living relatives of animals) and sponges (the most ancient animal phylum)
Cnidocyte
a specialized stinging cell found in cnidarians (jellyfish, corals, anemones) and used in capturing prey
Coelomate
an animal that has a true coelom, completely lined with mesoderm
Colony
an assemblage of individuals
Deposit feeder
an animal that eats its way through a food containing substrate
Detritivore
an organism whose diet consists mainly of dead organic matter (detritus). Varous bacteria, fungi, protists, and animals are detrivores. Also called decomposer
Deuterostomes
major lineage of bilaterian animals that share a pattern of embryological development, including formation of the anus earlier that the mouth, and formation of the coelom by pinching off of layers of mesoderm from the gut. Includes echinoderms and chordates
Ectoderm
the outermost of the three basic cell layers in most animal embryos: gives rise to the outer covering and nervous system
Endoderm
the innermost of the three basic cell layers (germ layers) in most animal embryos; gives rise to the digestive tract and organs that connect to it
