1
Q
What’s an animal?
A
- eukaryotic
- heterotrophic
- no cell walls
- motility at some point
- embryos go through blastula stage
2
Q
how many species of spoges?
A
8500
3
Q
what don’t they have?
A
- true tissue layers (instead made of specialized cells that work together)
- symetry
- nervous system
4
Q
what are the 3 gps of sponges?
A
- demosponges (90% of them) = marine and freshwater
- glass sponges = intricate silica skeletons and only marine
- calcarea = make calcium carbonate skeletons –> marine
5
Q
porifera body parts
A
central cavity (spongocoel)
pores (ostia)
osculum
“skeleton” = Ca or Si spicules connected with collagen
6
Q
3 cell types of porifera
A
pinacocytes = epidermal cells which contract to move water choanocytes = wave flagella to make a current archeocytes = amoeboid cells that digest food, store nutrients, secrete collagen, etc...
7
Q
what’s a tissue?
A
group of cells working together for a specific func.
-derive from 2-3 germ layers during embryo development
8
Q
germ layers
A
endoderm, ectoderm, mesoderm
9
Q
tissue types
A
epithelial, connective, muscle, nervous
10
Q
body plans
A
asymetric, bilateral symetry, radial symetry
11
Q
eumetazoans
A
- have true tissues
- all animals besides poriferans and placazoans
12
Q
diploblastic
A
- -just have 2 germ layers: endoderm and ectoderm
- jellyfish, corals, sea anenomies, and comb jellies (ctenophores)
13
Q
cnidaria
A
- precambian to present
- characterized by stinging cells (nematocysts) and nerve nests
- Anthozoans = sea anenomes, sea pens, and corals
- Scyphozoans = jellyfish
- Hydrozoans = Obelia and Hydra
- cubozoans = box jellies
14
Q
cnidarian life cycles
A
- alternate between polyp and medusa stages
- motile medusa release gametes which join to form a zygote which grows into a blastula which grows into a free-swimming planula larva which settles down to start its own colony as a polyp
- polyps can produce sexually or asexually via strobilation (budding of disc-like structures from gonozooids)
