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67 terms

Zoology, Terms for Exam 1

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adductor muscle scar
Region on interior of bivalve shell where the muscles attach to hold shell closed
Asconoid
Sponge body type; simple non-branching spongocoel
Byssus threads
Protein threads secreted by glands in the foot of bivalves; holds animal to substrate
cerrata
Secondary gill on dorsal surface of Opisthobranchs (Phylum Mollusca, Class Gastropoda)
Choanocyte
Flagellated cell lining interior canals of sponges; creates currents; captures particles in collar of microvilli held together by mucus; responsible for intracellular digestion and meiosis
coelom
Body cavity formed within mesoderm; created by layer of epithelium called the peritoneum; holds organs in place
colloblasts
Cells on tentacles of ctenophores that secrete glue for prey capture
corona
Ciliated "wheels" at anterior of rotifers; used for movement of water to capture suspended organic particles, such as bacteria, for feeding
ctenidium
Gill in molluscs; consists of an axis that holds layers of thin, vascularized sheets of tissue (has comb-like appearance, hence the name); also used for feeding in bivalves
dactylozooid
Defensive zooid with many nematocysts in polymorphic hydrozoa
diploblast
Development from embryos that have two layers of cells, the endoderm and ectoderm; adult organism has epidermis and gastrodermis (Cnidaria and Ctenophora are diploblastic)
epitoke
Sexual stage of some polychaete worms; separates from adult and swims up to spawn
eutely
Development in which all adults have the same, fixed number of cells (rotifers, nematodes, tardigrades)
flame bulb
Protonephridia found in flatworms, nemerteans, rotifers; ciliated "flame cell" pulls water from the coelom into a canal system for excretion; appears to function mostly for osmoregulation rather than excretion of wastes; Annelida have similar structure, but flame cell is flagellated (called a solenocyte)
foot
Muscular portion of mollusk used for movement
Gastrovascular cavity
Fluid filled cavity in Cnidaria (Ctenophores?)and Flatworms; serves for digestion and for hydroskeleton
gastrozooid
Feeding zooid of a polymorphic Hydrozoan
gonozooid
Reproductive zooid of a polymorphic Hyrdozoan
heteronomous
Annelid body type in which segments in different regions are specialize for certain functions
hinge & teeth
Portions of a bivalve shell; holds two sides of shell together
homonomous
Annelid body type in which segments are more or less the same
hydrostatic skeleton
Support structure in cnidarians and flatworms based on a fluid filled cavity surrounded by muscles that can put pressure on the cavity to stiffen and contract the animal; or release pressure to soften and extend the animal
labial palp
Extensions of tissue near the mouth of bivalves; selects appropriate particles to consume and creates pseudofeces of rejected particles
Leukonoid
Sponge body type characterized by extensively branching canals
mantle
Characteristic of molluscs; fold of epidermis that covers the vis the visceral mass and forms a cavity in which the ctenidia, anus, nephridiopore and gonopore are located; mantle secretes the shell and forms siphons, tentacles, and other structures
mantle cavity
Cavity in molluscs formed by the mantle; ctenidia lie in cavity and anus, gonopore, and nephridiopore open into cavity
medusa
Body form in Cnidaria; upside down sac with tentacles
mesoglea
Non-cellular layer of "jelly" and fibers between the epidermis and gastrodermis in cnidarian
mesohyl
Non-cellular material in the wall of a sponge; contains spicules, amoebocytes; lies between the choanocyte layer and the pinacocyte layer
mixonephridia
Structure in Annelids that serves for both excretion of wastes from mesonephridia to the outside of the body, as well as for transport of gametes
nematocyst
Organelle in cnidocytes of Cnidaria; when triggered by touch, shoots out a harpoon like hook with poisons, attached by a thread of protein; used to subdue prey and for defense
Osculum
Opening for excurrent water flow in sponges
osphradium
Sensory structure in bivalves; water flows that enters siphon flows first across this organ, which has chemosensors; enables siphon to "sniff out" directions in which food or mates might be found
Ostium
Opening for incurrent water flow in sponges
pallial line
Scar on shell that marks the edge where the mantle was attached
parapodia
Extensions of the body in polychaetes that serve as legs; contain setae
pericardial cavity
Region of coelom that encloses heart (in molluscs)
periostracum
External, organic layer of a molluscan shell
peristomium
The first segment in an Annelid; contains the mouth
polyp
Body type in Cnidaria; upright sac with tentacles
prostomium
"head" of a polychaete worm; region at anterior of peristomium
protonephridia
Simple kidney-like structures that serve as osmoregulatory and (in some) waste removal in flatworms, nematodes, nemerteans, and annelids)
pseudocoelom
Body cavity that is not lined with tissue and that does not originate from mesoderm
pseudofeces
Bolus of particles rejected by bivalve labial palps, bound up in mucus, and expelled into the mantle cavity
radula
Strip of stiff organic material holding chitinous teeth; used for feeding in molluscs
rhinophore
Chemosensory tentacles characteristic of Opisthobranchs
Segment
Repeating body unit in Annelids
setae
Chitinous bristles found in Annelids
siphon
Specialization of mantle for directing incurrent and excurrent water flow through body cavity in bivalves
Spicule
Crystal of CaCO3 or glass; forms skeleton in sponges
Spongocoel
Choanocyte cavities in sponges
statocysts
Organelle of maintenance of balance; found in Cnidaria, Ctenophores, molluscs
Syconoid
Spong body type with branched choanocyte lined channels
Torsion
Developmental process in gastropods that results in anus of adult located near mouth
Umbo
Oldest part of each valve in a bivalve shell
visceral mass
Tissue that contains gonad and digestive glands and structures in molluscs
Dioecious (gonochoristic)
Individual produces either eggs or sperm; includes members of phyla: nematodes, rotifers, annelids, molluscs, and tardigrades
Hermaphroditic
Individual produces eggs and sperm (serial hermaphrodite produces eggs and sperm but not at the same time); includes members of phyla: sponges, cnidarian, ctenophores, flatworms, annelida
Regneration
Ability to replace a body structure that has been lost
Trocophore larvae
Larval type characterized by an anterior tuft of cilia and a band of cilia; found in annelids and molluscs
Planula larvae
Larval stage in cnidaria
Veliger larvae
Larval stage in mollusca
Acoelomates
Animals that lack body cavities (sponges, cnidarian, ctenophores)
Pseudocoelomates
Animals that have a body cavity that is not derived from mesoderm; the cavity usually contains proteins, fibers, non-cellular material, and organs; nematodes, nemerteans, and rotifers
Coelomates
Organisms that have a body cavity derived from mesoderm; include annelids and molluscs and other "higher" animals
Asexual reproduction
Ability to reproduce via mitotically derived cells; common in sponges, cnidarian, Platyhelminthes, nemerteans, and annelida,
Parthenogenesis
Non-sexual reproduction in which females produce eggs that don't require fertilization and that produce only female offspring