Download Bio 104 Exam 4 Review – Animals Part I: Phylum Porifera – Phylum

Bio 104 Exam 4 Review – Animals Part I: Phylum Porifera – Phylum Mollusca (notes pages 28-36)
Animals are defined as “multicellular eukaryotes that are heterotrophic by ingestion.”
They have a diplontic life cycle in which the adult is always diploid.
They are classified based on their
Symmetry: asymmetrical, radially symmetrical, bilaterally symmetrical
Number of tissue layers: two (endoderm and ectoderm) or three (add mesoderm)
Type of coelom: acoelomates, pseudocoelomates or coelomates
Segmentation: non-segmented or segmented
All of the animal phyla have invertebrate members.
Phylum Porifera: the Sponges
Cellular level of organization (only ones at this level), have specialized cells, no tissue layers
Have collar cells (feeding), amoeboid cells (transport and spicule production), and epidermal cells
Classified by spicule type (chalk or glass), most have spongin
Digestion occurs intracellularly
Phylum Ctenophora: the Comb Jellies
Largest animal to use cilia for locomotion, radial symmetry
Phylum Cnidaria: Sea anemones, Jellyfish, Hydra
Radial symmetry, have cnidocytes which contain nematocysts
Two germ layers – endo and ectoderm (diploblasts)
Know the diagram of the medusa and polyp body plan, be able to label.
Class Anthozoa – sea anemones, corals; polyp is dominant form
Class Scyphozoa – true jellyfish; medusa is dominant form
Class Hydrozoa – Hydra, Obelia, Portuguese Man-o-War; polyp is dominant, planula larva in sexual repro.
Phylum Platyhelminthes: Flatworms
Three tissue layers (triploblasts), acoelomates, sac body plan
Planaria (free living)
Flukes (parasitic) – invade organs
Tapeworms (parasitic) – attach to intestinal wall with scolex, body segments called proglottids
Be able to compare and contrast between free-living and parasitic flatworms
Phylum Nematoda: the Roundworms
Tube-within-a-tube body plan, complete digestive tract, are pseudocoeomates, include pinworms,
hookworms and Trichinella, Ascaris, which are parasites, also free-living in soil and water.
Be able to diagram acoelomate, pseudocoelomate and coelomate body types, know which organisms are
which.
Protosomes vs deuterostomes: be able to compare and contrast, know which organisms are which.
Know advantages of true coelom.
Phylum Mollusca: the Mollusks
Three-part body plan: visceral mass, foot, mantle
Class Bivalvia – two shells – clams, oysters, scallops – have open circulatory system
Class Cephalopoda – “head foot”- octopuses, squid – closed circulatory system, camera eyes, beak, brain
Class Gastropoda – “stomach foot” – snails, slugs, conchs – undergo torsion during development
Exam 4 Word List
Word
diplontic
Symmetry
asymmetrical
radially symmetrical
bilaterally symmetrical
endoderm
ectoderm
mesoderm
coelom
acoelomates
pseudocoelomates
coelomates
invertebrate
Porifera
collar cells
amoeboid cells
epidermal cells
spicule
Ctenophora
Cnidaria
Cnidocytes
nematocysts
diploblasts
medusa
polyp
Anthozoa
Scyphozoa
Hydrozoa
planula
Platyhelminthes
Triploblasts
Acoelomates
Organism
Function or meaning
sac body plan
Scolex
Proglottids
Nematoda
Pseudocoeomates
Protosomes
Deuterostomes
Mollusca
visceral mass
foot
mantle
Bivalvia
open circulatory system
Cephalopoda
closed circulatory system
camera eyes
beak
Gastropoda
torsion