tutorial lab 3
what type of symmetry does phylum cnidaria have
radial symmetry
what body cavity do cnidarians have
gastrovascular cavity
stinging structures used to immobilize prey by cnidarians
nematocysts
mature cnidarians have how many cellular layers
2
what cell layers do cnidarians have
epidermis and a gastrodermis
diploblastic organisms
have 2 cellular layers
layer between the epidermis and gastrodermis in cnidarians
mesoderm (non cellular)
mesoderm allows animals to be
more organised in their stucture
triploblastic organisms
have three germ layers of cells
two forms of cnidarian
polyp and medusa
polyp
form of cnidarians that is tubular and closed at one end with a mouth surrounded by tentacles at the other end
medusa
form of cnidarian. umbrella shaped jelly-like free-swimming organism with a mouth at the end of a central projection called a manubrium
cnidarians do not require which systems
respiratory or circulatory
because the entire body surface participates in gas exchange and no cell is ever far enough away from the source to need anything more complex
hydra reproduce
asexually (budding) and sexually (sperm and ova)
gametes in hydra are produced in
spermaries and ovaries
obelia reproduces ___
alternation between polyp (asexual generation) and medusa (sexual generation)
club shaped polyps of obelia (cnidaria)
reproductive
polyps posessing tentacles on obelia (cnidarian)
nutritive polyps
perisarc surrounding the reproductive polyps
gonothecae
perisarc surrounding the nutritive polyps
hydrothecae
medusa tentacles contain
stinging cnidocytes with nematocysts inside them
manubrium in medusa
extends into the cavity and contains a mouth at its tip surrounded by four oral lobes
phylum Platyhelminthes
flatworms, dor0-ventrally flattened, bilaterally symmetrical, triploblastic
platyhelminthes are ___ blastic
triplo
germ layers flatworms posess
epidermis gastrodermis, layer of parenchyma developed from embryonic mesoderm
body plan of flat worms
acoelomate
dugesia
flatworm
dugesia has ___ digestive tract
a blind
Platyhelminthes have a ___ complex digestive tract that cnidarians
more
branches of the digestive tract are useful because
they increase the surface area for apsorbtion
food is brought to the gastrovascular cavity through __ in planaria
a muscular pharynx
clonorchis sinensis
flatworm that lives in the bile ducts of the human liver
clonorchis sinensis have a muscular pharynx leading to a blind digestive tract
true but the muscular pharynx is not protrusible
has an anterior mouth located at the bottom of a muscular sucker
clonorchis sinensis
oral sucker
used to suck in tissue fluids
free living flat worms have ___ excretory system
discrete
flame cells in flat worms
long cilia located at the blind end of the tubules within the body
function of flame cells
propel excess water through the tubules of the osmoregulation system in free-living flatworms
gastrovasular system in flat worms
transports nutrient materials
if gastrovascular system is not present in flatworms, internal transport occurs via
diffusion
planarians have either female or male sex organs
false they are hermaphroditic
musculature of ascaris sp contains what muscle
longitudinal only that work simultaneously against the fluid in the psudocoelom
peritoneum
thin epithelial lining separating the body cavity from the body wall
intestine infolding in annelids
typhlosole
cells surrounding the exterior surface of the intestine in annelids
chloragogue cells
function of chloragogue cells
an accessory digestive gland, the site of glycogen synthesis deamination of proteins and production of ammonia and urea
nephridia
within the coelom between the intestine and the body wall appearing as wavy lines
terrestrial arthropods tracheal system
spiracles lead to tubules (tracheae), branch into fine tubules (tracheoles) reach groups of cells in the body
provides large surface for respiratory exchange