Basal Animals Flashcards
What are the phyla that make up basal animals?
Ctenophora (comb jellies).
Porifera (sponges)
Cnidaria.
Describe ctenophores (comb jellies).
1mm to 1.5m in size.
Move using cilia.
Neural system + muscles form a net.
Describe sponges.
Mostly marine and sessile. No muscles or nerve cells. Complex skeletal lattice. A few mm to 1 metre in size. Radial or asymmetrical body symmetry.
Describe the anatomy of a sponge.
No true organs/tissues. System of water canals. Incurrent pores = ostia. Outcurrent pores = osculum. Interior cavity = atrium/spongocoel.
How do pinacocytes, choanocytes and archaeocytes differ in sponges?
Pinacocytes are flat, covering the outer surface and lack flagella. Choanocytes possess flagella and microvilli to catch food. Archaeocytes function in digestion.
What are the 3 sponge body plans?
Asconoid = hollow cylinder. Syconoid = interdigitating inpockets/outpockets. Leuconoid = complex network of water vessels.
What are suspension feeders?
Organisms that capture suspended food particles from water by passing a current of water through their body.
What is a sponge’s skeleton made from?
Spongin (if you forget this you are a moron).
What groups make up cnidaria?
Hydroids, jellyfish, sea anemones and corals.
What is the diploblast body plan?
Basic ‘sac’ body plan. The gastrovascular cavity acts as a hydrostatic skeleton.
What are the 2 variants of the diploblast body plan?
Medusa and polyp.
What is the medusa variant of the diploblast body plan?
Mouth + tentacles face downwards.
What is the polyp variant of the diploblast body plan?
Mouth + tentacles face upwards.
What is mesoglea?
The translucent, jelly-like substance found in cnidarians.
What are cnidocytes?
Cells on the tentacles of cnidarians that discharge cnidae that envenomate prey.
