CNIDARIA Flashcards
cnidaria is also called
coelenterata
their two main features
nematocysts and polymorphism
which give rise to nematocysts
cnidocytes
tentacles are present around which structures
mouth and body
ectoderm give rise to cnidocytes which give rise to
nematocysts
size range
microscopic hydra to 2 meter long branchioceranthus
branchioceranthus size
about 2 meters
hydra can be seen by
microscope
habitat
aquatic
food source
carnivores
form of life
sessile, motile, and colonial
sessile cnidaria example
hydra, obelia, sea anemone
motile
jelly fish
aurelia- medusae are dominant and polyps are reduced
example of colonial cnidaria
obelia, physalia, vellela
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symmetry
radiata
germ layers
two layers and mesoglea
organs are
present byt organ system is absent
which cells are specialized for digestion of food
1. ectodermal
2. endodermal
endodermal cells `
ecto give rise to cnidocytes
the digestive cavity is called
enteron/ gastrovascuar cavity
one openng is present
branchioceranthus is which polyp
hydrozoan
how many zooids are present
main two wesay 5 are possible
polyps and medusae role
nutritive and reproduction respectively
characteristics of medusae
form of life
motile in nature
DIPLOID
reproductive role
have gonads
produce gamets
diploid in nature
characteristics of polyps
nutrition
sessile
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obelia has three types of zooids
alternation of generation is present in
obelia
examples
jelly fish( aurelia) , sea anemone( actinia), hydra, obelia, physalia, corals( madrepora), vellela
aurelia
jelly fish
medusae are dominant and polyp are reduced
actinia
sea anemone
sessile
only polyps
gastrovascular cavity divided into large partitions by septum called MESENTERIES
enteron - cavity
madrepora
corals
exoskeleton CaCO3
form small coral islands and large coral reefs
rock gardens, aquaria, jewllery
hydra reproduces asexualy through
budding
repro of obelia
blastocyle(sessile)- asexual repro- medusae(motile)- sexual repro- gametes- join to form colonies
zooids present in obelia
nutritive- gastrozoids
asexual repro- gonozoids and blastocyle
sexual- medusae
