Topic 5: Animals None / Radial Symmetry Flashcards
Phylum Porifera
- Protostomes
- sponges
- lack of tissue layers
- asymmetrical
- sessile
- limited integration of cells
- shaped very with habitat
- no true coelom
What are the 2 layers of cells in the sponge body wall
- Pinacocytes
- Choanocyte
Pinacocytes
Layer of cells in sponges that make up the epithethelial pinacoderm
Choanocyte
Layer of cells in sponges that consisted of flagellum surrounded by micro villa
What is the purpose of choanocyte in sponges?
- allow water to enter through pores and leave via accumulation
- trap food particles
Mesohyl
Gelatinous matrix that separates the 2 cell layers (pinacocytes and choanocyte) in sponges
Archaeocytes (amoeboid cells)
- found in the mesohyl of sponges
- digest and transport food
- secrete materials to form spicules to strengthen the sponge body and deter predators
Osculum
Opening to the environment in sponges
Phylum Cnidaria
- Protostomes
- all aquatic or marine
- no true coelom
- radial symmetry + nerves
- gastrovascular cavity with mouth
- NO organ / organ systems
- are diploblastic (2 layers)
Gastrodermis
The endodermis of Cniararia
Diploblastic layers of Cnidaria
- Inner gastrodermis
- Outer epidermis
- Gelatinous mesoglea between layers
Cnidaria can exist as….
- Downward facing medusae
- Upwards facing polyps
- Both
Medusae
When a Cnidarian is downward facing
Polyps
When a Cnidarian is upward facing
Cnidarian Body Plan
- mouth ringed with tentacles
- capture prey with tentacles and stinging nematocytes stored in cnidocytes
Class Scyphozoa and Cubozoa
- Phylum Cnidaria
- jellyfish and club jellies
- dominated by medusa stage
Class Anthozoa
- Phylum Cnidaria
- corals and sea anemones
- exist only as polyps
Class Hydrozoa
- Phylum Cnidaria
- alternate life cycle between polyp (asexual) and medusa (sexual)
Phylum Ctenophora
- comb jellies
- lack nemotocyts
- have long tentacles to capture food
- posses row of cilia for locomotion
What key structures are used by Ctenophora used for capturing food?
Arms that are sticky (do not sting) by colloblasts
