2370 Quiz 2

lophotrochozoa

an informal group that includes flatworms, annelids, and molluscs

coelom

body cavity, not referring to gut

acoelomate

no body cavity

what body plan do flatworms have

acoelomate

what is the coelom filled with

partially filled with body fluid

what is special about the flatworm head

has cepahlization

frontal

front to back (sideways)

sagittal

up and down (tall)

how many species of platyhelminthes are there

20,000

what evolved first? Coelomates or Acoelomates

Coelomates

what do flat bodies provide for flatworms

increased external surface area

what skin layers do flatworms have

triploblastic, ectoderm, mesoderm, endoderm

what symmetry do flatworms have

bilateral

where do flatworms live

freshwater, marine, and terrestrial

what feeding habits do flatworms have

scavenger and predator

free living flatworms

turbellaria

what kind of epidermis do flatworms have

ventral ciliated epidermis

what do rhabdite cells do

secrete mucous and chemical toxins to subdue prey

what is lost in adult tapeworms

digestive system

how many openings do flatworms have and where is it

one, the mouth

what is special about flatworm pharynx

flatworms have a muscular extendable pharyx as a specialized feeding organ

where does the mouth lie in flatworms

at the top of the pharynx in the middle of the body

what does the feeding tube do in flatworms

sucks in prey and dead tissue

how does the pharynx feed

it comes outside of the body to grab food and pulls it in

what helps in osmoregulation of flatworms

flame cells and osmoregulatory tubule

why do flatworms have to osmoregulate in freshwater

because the internal body of flatworm has more salts and ions than the environment

scientific name for flame cell

protonephridia

what do flame cells do

remove excess water and minor role in excretion of wastes

where are execratory pores located in flatworms

all over the body

flow of body fluids in flatworm

enter through parenchyma tissue, go through flame cell, then are pushed through hollow tubule body system and exit through excretory pores

what encourages the movement of fluids through tubules

tufts

where are needed substances reabsorbed

tubule walls

what is a flame cell covered in

"mesh" that allows fluids to enter

where do wastes exit the flatworm

excretory pores

ganglion

a cluster/mass of nerve cell bodies

transverse nerve

ladder like nervous system of flatworms

cerebral ganglia

Two clusters of nerve cells at the anterior end of flatworms

flatworm stem cells

neoblasts

flatworm infections in frogs

there is a link between atrazine and lethal fluke infections. the fluke makes the infection more deadly

what is the intermediate hosts of flatworms

leopard frogs and freshwater snails

class cestodia

tapeworms

what are tapeworms

endoparasites

what adaptations do endoparasites have

attachment devices, no digestive tract, increased resources for reproduction in each proglottid

fasciola hepatica

sheep liver fluke

what part of fasciola hepatica lifecycle is asexual

miracidium stage. One miracidium can produce thousands of cercaria

fasciola hepatica life cycle

adult, miracidium, sporocyst, rediae, cercariae

zombie snail

Leucochloridium

what happens in zombie snail

sporocysts attach to snail and take over body

trematode intermediate host 1

california host snail

trematode intermediate host 2

marsh fish, crabs, birds, snails

trematode final host

herons and other top predators

cercaria

before metacercaria stage in fasciola hepatica, have active tail that is used in water to move onto vegetation

miracidium

free swimming ciliated larval stage that locates freshwater snail intermediate host

metacercaria

dormant stage of fasciola hepatica that is on vegetation waiting to be eaten by final host

what causes the eggs of taenia solium to break open and cyst

digestive enzymes

taenia solium

pork tapeworm

taenia solium life cycle

human passes eggs in feces, pigs eat eggs, oncospheres hatch, oncopsheres develop into cystocerci, humans eat cystocerci , scolex attaches to intestine and adult forms

when do pork tapeworms develop in the muscle

when human eats oncosphere

major molluscan classes

polyplacophora, gastropoda, bivalvia, cephalopoda

polyplacophora shell

has overlapping plates for shell

gastropoda shell

coiled or no shell

bivalvia shell

animal closed within two halves

cephalopoda shell

reduced or absent

aculifera

polyplacophora, aplacophora

chonifera

monopolacophora, cephalopoda, scapholopoda, gastropoda, bivalvia

traits of ancestral mollusks

dorsal visceral mass, ventral muscular foot, mantle, mantle cavity, shell, radula

what is the shell of mollusks made out of

calcium carbonate and protein matrix

what part of the mollusc makes pearls

nacreous layer

what are the layers of a mollusc shell

periostracum, prismatic layer, nacreous layer

what is on the outside of the shell

conchiolin protein

what is the only hard part in mollusc

radula

what does the radula do

rasp and scrape food

how do molluscs without shells protect themselves

bright color warns predator of toxins

what are the larval stages of mollusca

Trochophore and Veliger

what comes first trochophore or veliger

trochophore is precursor to veliger stage

what makes up the veliger larva

shell on top, velum on the bottom

what is the only class without a radula

bivalve

how do bivalve eat

sessile filter feeding

what is the oldest part of the shell

umbo

what is the dorsal end of the bivalve

hinge ligament

what opens and closes the shells of the bivalve

adductor muscles

where does water enter the bivalve

incurrent siphon

where does water exit the bivalve

excurrent siphon

what does the labial palps do

direct food to the mouth in bivalves

what directs food to the mouth in bivalves

labial palps

feeding in bivalves

gills/gnetida covered with mucus and cilia trap food particles on the surface of the gills, tracts of cilia at the gill edges beat together to move food to the edge of the gills, labial palps move food to the mouth

typhosole

an fold in the intestinal wall that increases surface area of the intestine for digestion and absorption of nutrients

crystalline style

a rod that projects into the stomach of bivalves. It rubs against the gastric shield to release digestive enzymes.

what does the rotation of the crystalline style do?

pulls the food cord into the esophagus and stomach and releases digestive enzymes

how old is the oldest clam in the world

ming the clam, 507 years old

what percentage of north american freshwater clams are imperiled

70%

how many species of clams are extinct

35

how many species of clams are endangered

70

how many species of clams are critically endangered

180

what class of mollusca is the largest

class gastropoda

what kind of shell do gastropoda have

a coiled univalve

what class is most closely related to bivalves?

gastropoda

what development stages do gastropods have

trochophore and veliger larval stages

what are the shells of gastropods made of

calcium carbonate

what is the oldest part of gastropod shells

apex