Phylum Porifera Flashcards
what are the porifera?
sponges! most basal metazoans
- no true tissues, no tissue layers (multiple cell types throughout sponge body)
- no mouth
- no gut
- over 10,000 species though!
sponges are ____ organized
loosely
how do sponges capture food?
choanocytes - flagellated cells
how do sponges compare to other animals on the phylogenetic tree?
•Of all animals, sponges are the least integrated, branch off earliest on phylogenetic trees, and appear earliest in the fossil record
what type of metazoans are sponges?
parazoans!
where do the 10,000 species of sponges mostly live?
in marine environments, some freshwater too
how do sponges excrete waste, perform gas exchange, and absorb nutrients?
by diffusion of water across its cell membrane
what are sponge spicules?
supportive
made of calcium carbonate or silica
what is sponge spongin?
soft flexible protein, support for the sponge
porocytes and epidermal cells
outer layer of the sponge
- outer protective layer
- porocytes form tiny openings (ostia) and allow water to pass to the inner chamber
spongocoel
inner chamber of the sponge
amoebocytes
roam actively throughout the sponge body and transport materials
mesohyl
gelatinous layer
-between inner and outer cell layers
choanocytes
flagellated cells lining the internal chamber of the sponge
responsible for moving water through the sponge
osculum
large excurrent opening at the top of the sponge
