asymmetrical
no symmetry
radial symmetry
multiple planes of identical pieces
bilateral symmetry
one plane creating only 2 identical pieces
endoderm
innermost layer of the embryo
mesoderm
middle layer of the embryo
ectoderm
outer most layer of the embryo
coelom
body cavity between the digestive tract and outer body wall
acoelomates
do not have a cavity, it is completely filled with mesoderm tissue
psuedocoelomates
has a cavity that is not surrounded by mesoderm tissue. along the outer body wall is mesoderm tissue.
coelomates
body cavity that is completely surrounded by mesoderm
protostomes
the blastopore forms the mouth
dueterosomes
blastopore forms the anus
porifera
4-5 cell types
asymmetrical
filter feeders
intracellular digestion
lack any germ
asexual and sexual reproduction with external fertilization
Ways to increase chances
most are marine, but a few are fresh water
cnidaria
all are aquatic
carnivorous, filter feeders, many have symbiotic algae
radial symmetry
2 germ layers, endoderm and ectoderm w/ mesoglea b/w them
tentacles containing cnidocytes used to capture prey
digestive sac
nerve net
polyp (for sessile species) and Medusa (for free species)
asexual and sexual reproduction with external fertilization
ctenophora
radial symmetry (some evidence of bilateral symmetry)
all aquatic most are predatory
2 germ layers; ecto- and endo- w mesoglea b/w them
digestive sac
have cilia along their body that propels them
most have colloblasts
nerve net
asex. and sex. rep. with ext. fert.
bioluminescent!!
platyhelminthes
aquatic and terrestrial; free living and parasitic
“Triploblastic” ecto- meso- endo-
acoelomate
bilateral symmetry (cephalization)
digestive sac
concentration of nervous tissue in the head area, some eyespots can detect light/dark
asex. and sex. rep. with ext. and int. fert.
some move through muscular contractions, others “glide” along with cilia
rotifera
aquatic
bilateral symmetry with cephalization
psuedocoelomate
protosomal digestive tube
ciliated structure known as the corona at the “head”
simple nerve system with a “Brain”
sexual reproduction w/ internal fertilization
nematoda
aquatic or terrestrial, many are parasitic
a lot of human diseases are caused by round worms
3 germ layers
psueocoelomate
bilateral symmetry with cephalization
protosomal digestive tube development
primarily sexual with internal fert.
annelida
aquatic or terrestrial
3 germ layers
coelomate
bilateral symmetry with cephalization
protosomal digestive tube development
closed circulatory system
primarily sexual reproduction with internal fertilization
trochophore larva
Mollusca
aquatic or terrestrial
3 germ layers
Coelomate
Bilateral symmetry with cephalization
protosomal digestive tube development
soft body, some form a shell of of calcium carbonate
trochophore larvae
primarily sexual reproduction
3 body parts: the foot, the mantle, the visceral mass
3 Major Classes of Mollusca
Cephalopoda, Gastropoda, Bivalvia
Cephalopoda
“Head Foot” Squid and Octopi
closed circulatory system
internal fertilization
most intelligent of “invertebrates”
Gastropoda
“Stomach-Foot” Slugs and Snails
open circulatory system
internal fertilization with many being hermaphrodites
Bivalvia
“Two Shells” Clams, Mussels, Oysters
open circulatory system
external fertilization
Arthropoda
3 germ layers
coelomate
bilateral symmetry with cephalization
protostomal digestive tube
3 specific traits: segmented body, exoskeleton (chitin), jointed appendages
open circulatory system
sex. rep. with both int. and ext. fert.
3 different classes in Arthropoda
crustacea, chelicerae, insecta
Crustacea
(Crabs, Crayfish, Barnacles)
10 legs
Chelicerae
(spiders, scorpions, ticks)
8 legs
Insecta
(ants, butterflies, bees)
6 legs
Echinodermata
(Sea stars, sea urchins, sea cucumbers, crinoids)
aquatic
3 germ layers
coelomate
bilateral symmetry as a larva, as an adult, radial symmetry
deuterostomal digestive tube development
endoskeleton
water vascular system instead of blood
Tube feet which aid in movement, respiration, and excretion (inflates with water)
sex. rep. with ext. fert.