porifera and cnidaria Flashcards
what group are the phylum porifera in?
the basil group (earlier lineage to break away from the common ancestor)
what animal does the phylum porifera refer to?
sponges!
what are some characteristics of sponges?
- they have pores
- most abundant animal in the ocean
- most are sessile (do not move around), only the larvae move
what is the morphology of a sponge?
- no tissues or organs (no gut, muscles, nerves)
- some cells have specialized functions
- spicules (their version of a skeleton) give them structural support
- some sponges have only tough collagen-protein network for support
why are sponges considered to not have tissue even though some cells have a specialized function?
their ‘tissue’ is just a collection of cells, there is no separation from a membrane
in sponges, water gets pumped into _________ and it traps food
coenocytes
what are the two cells of the porifera?
choanocyte and mesophyll
what feeding process do sponges undergo?
filter feeding - suspension feeding
at the base of the choanocyte, food particles are engulfed by?
phagocytosis!
what is the function of the amoebocytes in filter feeding?
amoebocytes are fixed, and can move throughout the mesophyll taking food wherever is needed
what are some reproductive qualities of sponges?
- most sponges are hermaphroditic (possess male and female organs)
- sequential - can be simultaneously male and female, or switch from male to female
- they do not have ovaries or testes
how do egg cells arise in sponges?
from modified amoebocytes
how do sperm cells arise in sponges?
from modified choanocytes
do they use external or internal fertilization?
mostly internal
how do sponges reproduce?
- release of flagellated modified choanocyte (sperm)
- fertilizes amoebocytes in the mesophyll
- becomes a free-swimming larva