Exam 2 Flashcards
what are some key characteristics of the Phylum Cnidaria?
•diploblastic
•shallow marine environments, some freshwater
•radial, biradial
•free-swimming medusae
•sessile polyps
•fossils date back to ~700 mya (pre-cambrian)
•9,000 species
what are Cnidocytes?
contain nematocyst, stinging organelle; diploblastic
Mesoglea (jelly) is:
extracellar matrix that lies between layers; 95% water
in the Phylum Cnidaria tentacles _________ & muscles _________
•tentacles encircle mouth/oral region
•muscles extend, contract, bend, & pulse
Phylum Cnidaria sense organs:
balance= statocysts
photosensitivity= ocelli
what does the nerve net do in phylum cnidaria?
transmit nerve signal across synapse (unidirectional like us) or back (not like us)
asexual reproduction in phylum cnidaria:
budding in polyps
sexual reproduction in phylum cnidaria:
•by gametes of all medusae, some polyps
•monoecious or dioecious (separate sexes)
phylum cnidaria lacks what 2 systems?
excretory & respiratory systems
acoelomate (lacks a coelom)
phylum cnidaria- polyps:
•sedentary
•mouth leads to blind cavity
•colonial forms specialized for feeding, reproduction, or defense
phylum cnidaria- medusa:
•bell or umbrella-shaped
•usually free-swimming
•mouth directed downward
•tentacles down from rim of umbrella
•dioecious (sexually)
polyp development (cnidaria)
•zygote develops —> motile planula larva
•planula settles, metamorphoses into a polyp
•produce other polyps asexually
•polyps eventually produce a free-swimming medusa by asexual reproduction (budding or strobilation)
Cnidaria: feeding and defense
•many are predators
•cnidocytes:
- produces > 20 types of cnidae
- one type = nematocyst
- tiny capsules, chitin-like material, coiled filament (barbed or spined), covered by operculum, tactile stimulation
cnidaria:
after discharge _________ is absorbed and another develops
cnidocyte
cnidaria feeding cycle:
- water rushed into capsule
- operculum opens, rapidly launched the filament
- barbs inject poison into prey
- prey moved to mouth
describe the class hydrozoa
•most marine, colonial (polyp & medusa)
-hydra is atypical
-obelia is typical
•typical hydroid has a base, a stalk, less than or equal to 1 terminal zooids
what is a stolon?
root like structure
what is hydrocauli?
tubes connecting individuals
what is perisarc?
sheath of chitin around hydrocauli
characteristics of hydra:
•freshwater
•worldwide
•feed on small crustaceans, insect larvae, & worms
•3 types of cnidae (catch, move, adhere prey)
•asexual reproduction by budding
•most dioecious (egg, sperm external)
•encysted zygota endure winter, young hatch in spring
the sessile stage in the life cycle of cnidarians is?
polyp
free-swimming stage that reproduced sexually in the life cycle of cnidarians is?
medusa
the gill cover in bony fishes; keratinized plate in some snails is:
operculum
stinging organelle in cnidarians is:
nematocyst
sense organs of equilibrium; a fluid-filled cellular cyst containing one or more granules used to sense direction of gravity
statocyst
free-swimming, ciliated larval type of cnidarians
planula
what is a zooid?
individual polyp animal
the portion projecting from the oral side of a jelly medusa
manubrium
flaplike extension of the mouth of a scyphozoan medusa that aids in feeding
oral lobe
repeated linear budding of individuals, as in scyphozoan ephyrae, or sets of reproductive organs in tapeworms
strobilation
shelflike extension of the subumbrellar edge in cubozoans
velarium
the end of a cnidarian polyps bearing the mouth
oral disc
transverse plates of fused cilia
comb plates
comb jellies
ctenophores
region of an animal opposite the mouth
aboral pole
a simple eye or eyespot in many types of invertebrates
ocellus
tadpolelike juveniles of trematodes (flukes)
cercariae
pelagic means:
free swimming
evolutionary process by which specialization became localized in the head end of animals
cephalization
blastopore
mouth
lophotrochozoas are
larva with whorls of tentacles
neodermis
new skin
protonephrida
flame cell
rheoreceptors
sense direction of water currents
chemoreceptors
detect food in planaria
the host in which sexual reproduction of symbiont occurs
definitive/final host
organs in the epidermis of most turbellarians, with three cell types: viscid and releasing gland cells and anchor cells
dual gland
organism with both male and female functional reproductive organs
hermaphrodite
host in which some development of symbiont occurs, but no maturation or sexual reproduction
intermediate host
fluke juvenile that has lost its tail and become encysted
metacercariae
free swimming ciliated larva; larval stage in the life of flukes
miracidium
posterior attachment organ of a monogenetic trematode
opisthaptor
comb rows
equally spaced bands made of comb plates
unisexual reproduction involving the production of young by females not fertilized by males
parthenogenesis
the part of the digestive tract between the mouth cavity and the esophagus that is common to both digestive and respiratory tracts
pharynx
free-swimming helmet-shaped larva in nemertea
pilidium
tubular sucking or feeding organ with mouth at the end; muscular tube
proboscis
portion of a tapeworm containing a set of reproductive organs
proglottid
primitive osmoregulatory or excretory organ consisting of a tubule terminating internally; unit of a flame bulb system
protonephridia
larval stage in the life cycle of flukes
rediae
rodlike structure in cells of epidermis in turbellarians; discharged in mucous
rhabdites
the dorsal tubular cavity that contains the inverted proboscis
rhynchocoel
bears suckers and sometimes hooks in tapeworm
scolex
larval stage in the life cycle of flukes
sporocyst
chain of proglottids in tapeworm
strobila
similar to nerve net in cnidarians; specialization of neuron types (sensory, motor); longitudinal nerve cords lie under muscle layer
subepidermal nerve plexus
feeding device of ciliated tentacles
lophophore
diploid eggs that form diploid females; fertilized by males
amictic
haploid eggs of rotifers
mictic
ciliated crown
corona
shared opening; posterior chamber of digestive tract (bladder)
cloaca
protective, noncellular, organic layer secreted by external epidermis
cuticle
held together by muscles; large horseshoe-shaped lophophore
inarticulata (brachiopoda)
hinge with an interlocking tooth-and-socket arrangement
articulata (brachiopoda)
external chamber
ovicell
extend lophophores and filter feed
zooids
exoskeleton
zoecium
small or short fleshly stalk
pedical
embryos asexually reproduce
polyembryony
has rows of recurved spines; penetrate and may rupture hosts intestines
probiscis
secrete adhesive substance in rotifers
pedal glands
asexually produced by budding in ectoprocta
statoblasts
ring of cilia used for feeding and swimming in rotifers
trochal disks
jaws of rotifer
trophi
separate segments in annelids
septa
mesoderm arranged segmentally in longitudinal series in annelids
somite
body segments marked by circular groves
annuli
repetition of organs in segments
metamerism
tiny chitinous bristles; anchor segments in earthworms; help aquatic worms swim
setae
anterior to mouth
prostomium
bears mouth
peristomium
terminal portion bearing anus
pygidium
mesoderm; lines body wall & forms dorsal & central mesentries
peritoneum
coelom filled with fluid that contracts muscles in annelida
hydrostatic skeleton
alternate waves of contraction for burrowing
peristalsis
paired bundles of setae on most segments — crawling; anchor to tube
parapodia
errant polychaetes
predators/scavengers
sedentary polychaetes
consume particles
ciliated sensory puts that are provably chemoreceptive
nuchal organs
cerebral ganglia
concentration of nerves cells in the head
statocysts in annelids (polychaeta)
some burrowing/tube-building used to orient body
ring of secretory cells found in a band around the body
clitellum
short anterior forepart, long slender trunk, and a small, segmented opisthosoma
body of a siboglinidae (annelida)
early larva in polychaeta
trochophore
in clitellata young develop inside of what?
a cocoon secreted by clitellum
annelids blood contains colorless ameboid cells and a dissolved respiratory pigment called
hemoglobin
protective covering of a resting or developmental stage in annelids
cocoon
in annelida the ______ is well developed and divided by septa; filled with fluid as hydrostatic skeleton (except leeches)
coelom
dorsal and ventral ______ are formed by perutoneum inside coelom (annelida)
mesentries
in annelids the epithelium secretes outer transparent, moist ______
cuticle
organs of secretion; pair in each segment except first three and last one
metanephridia
feather like structure extending from head of sedentary polychaetes; used in feeding in suspended particles
radiole
in hirudinea, there’s a anterior and a posterior ____
sucker
segments of clitellata
segments variable; few setae per segment
segments of hirudinida
fixed number of segments (normally 34; 15 or 27 in some) with many annuli
segments in annelida can be determined by:
annuli, metamerism, and septa
space between mantle and body wall (houses gills or lung)
mantle cavity
secretes the shell over the visceral mass
mantle
attachment to substratum or locomotion
-siphon jet of squids (modified)
-attachment disc (limpets): secrete mucous
-hatchet foot of clams: burrowing
foot
a rasping, tongue-like organ unique to molluscs
radula
in mollusca what secreted by mantle layers?
the shell
outer layer of shell composed of conchiolin
periostracum
intermediate free-swimming larval stage in molluscs
veligar
nacreous layer
inner layer of shell
prismatic layer
middle layer of shell
gills in mantle cavity
ctenidia
photosensitive structures like eyes (polyplacophora)
esthetes
“bearer of many plates”
chitons
larvae into juveniles (polyplacophora)
trocophore
smallest and oldest whorl
apex
covers shell aperture (not all) in gastropoda
operculum
developmental process that changes the relative position of the shell, digestive tract, anus, nerves in the digestive tract, and mantle cavity
torsion (developmental)
in gastropoda venom is a ____
conotoxin
living young hatch from eggs within mother
ovoviviparous
the mantle and mantle cavity are inside of what?
visceral mass
one of the two shells of a bivalve mollusk
valve
