Tutorial 3 Flashcards
phylum cnidaria
diplobastic organsims
symmetry in phylum cnidaria
they have radial symmetry
2 layers in cnidaria
epidermis and the inner gastrodermis
2 body forms of the cnidaria
polyp and medusa
what are cnidocytes
they are specialized cells
cnidocyctes -> nematocysts -> that are used to immoblize the prey
what is the characteristic feature in the phylum cnidaria
they have a body cavity called as the gastrovascular cavity
what is the name of the layer that is found in between the epidermis and the gastrodermis
mesoglea
mesoglea
it is the non cellular layer in between the epidermis and the gastrodermis
ingestion and digestion in the phylum cnidaria
the prey is immoblized by the tentcales -> ingested -> degraded in the gastrovascular cavity -> the small particles would be ingulfed by the gastrodermial cells by PHAGOCYTOSIS
Polyp reproductive generation
asexual
Medusa reproductive generation
sexual
obelia
- medusa body form
- they live in colonies
hydrothecae
feeding nutritive polyps that posses tencales
Gonothecae
club shaped, lack tentacles and are the reproductive polyps
perisarc
the branches of the colonies of the obelia are covered with a transparent sheath known as perisarc
manubrium
cavity found in medusa, which contains a mouth at its one tip and surrounded by 4 oral lobes
phylum Platyhelminthes
flatworm like animals
example - planarian
symmetry in phylum Platyhelminthes
bilaterally symmetrical
cellular layers in flatworms
the phylum Platyhelminthes are all triploblastic
body cavities in flatworms
The phylum Platyhelminthes lack a body cavity hence are acoelomate but otherwise are very well developed.
the three germ layers in Platyhelminthes
gastrodermis < parenchyma tissues < epidermis
feeding and digestion in planarian
they are mainly carnivorous
they have a blind digestive tract i.e. only one opening
osmoregulation and excretion in planarian
the excess water and waste enters the flame cells system and is then propelled through the tubules by beating of the cilia
