Exercise 18 Flashcards
What are the four animal phyla?
- Porifera
- Cnidaria
- Platyhelminthes
- Rotifera
Porifera
- sponges
- asymmetrical
- don’t have tissue
Cnidaria
- jellyfish
- radial symmetry (circular)
Platyhelminthes
bilateral symmetry
Rotifera
bilateral symmetry
Animal characteristics
- multi-cellular
- heterotrophic
- diploid; sexual reproduction more common
- motility
- larva form in many
- germ layers
Porifera body organization
none
Porifera level of organization
cell specialization
Porifera body support
spicules, spongin fibers
Special characteristics of Porifera
pores, spongocoel, osculum, choanocytes (collar cells)
Collar cells
grab food
How are sponges classified?
based on what skeletal spicules they have
Class Calcarea
fragile
Class Demonspongiae
spongin fibers
Cnidaria habitat
mostly marine
Cnidaria body organization
radial symmetry
Cnidaria level of organization
tissue (ectoderm and endoderm only)
Cnidaria body support
hydrostatic gut
Cnidaria life cycle
sexual reproduction, larva = planula, asexual reproduction
Cnidaria special characteristics
nematocysts, polyp, medusa
Three classes of cnidarians
- Hydrozoa
- Scyphozoa
- Anthozoa
Class Hydrozoa
possesses both polyp and medusa stages
- hydra, Portuguese Man-of-War
Class Scyphozoa
Medusa only
- jellyfish
Class Anthozoa
Polyp only
- corals, sea anemones, sea fans
Nematocysts
capsule-like organelles within the stinging cells of cnidarians
Examples of Platyhelminthes
flatworms (tapeworms, Planaria, flukes)
Platyhelminthes body organization
bilateral symmetry, head, incomplete gut
Platyhelminthes level of organization
organ system (all three germ layers)
Platyhelminthes special characteristics
brain, flame cells
