3 Written Questions

1. Level of Organization: Organ System
   Germ layers: three
   Symmetry: bilateral
   Cephalization: present
   Body Cavity: Coelom
   Segmentation: Present
   Digestive system: Separate mouth and anus
   Circulatory System: closed
   Respiratory System: absent
   Nervous System: head ganglia with paired ventral cords; ganglia in each segment
   Reproduction: Sexual (some hermaphroditic); fragmentation
   Support: Hydrostatic skeleton
   Note: segments=ringlike depressions on the surface; internally segments contain identical copies of nerves/excretory structures/muscles-->good for locomotion and more complex movements; external and internal fertilization
2. Level of Organization: Organ System
   Germ layers: three
   Symmetry: bilateral larvae, radial adults
   Cephalization: absent
   Body Cavity: coelom
   Segmentation: absent
   Digestive system: Separate mouth and anus
   Circulatory System: absent
   Respiratory System: tube feet, skin gills, respiratory tree
   Nervous System: head ganglia absent; nerve ring and radial nerves; nerve network in the skin
   Reproduction: sexual (some hermaphroditic); asexual by regeneration (rare)
   Support: endoskeleton of plates beneath outer skin
   Note: name means hedgehog skin, tube feet=delicate cylindrical projections that extend from the lower surface of the body and terminate in a suction cup-->enable for locomotion, respiration, and food capture
3. Level of Organization: Tissue--lack organs
   Germ layers: two
   Symmetry: radial
   Cephalization: absent
   Body Cavity: absent
   Segmentation: absent
   Digestive system: gastrovascular cavity; some intracellular
   Circulatory System: Absent
   Respiratory System: absent
   Nervous System: nerve net
   Reproduction: Sexual; asexual (budding)
   Support: Hydrostatic skeleton
   Notes: named for cnidocytes--stinging cells; fluid in cavities give shape; polyps and medusa

3 Multiple Choice Questions

1. Level of Organization: Cellular--lack tissues and organs
   Germ layers: absent
   Symmetry: absent
   Cephalization: absent
   Body Cavity: absent
   Segmentation: absent
   Digestive system: Intracellular
   Circulatory System: Absent
   Respiratory System: absent
   Nervous System: Absent
   Reproduction: Sexual; asexual (budding)
   Support: Endoskeleton of spicules
   Notes: eat by filtering; sessile
   1. Flatworms (Platyhelminthes)
   2. Segmented Worms (Annelida)
   3. Roundworms (Nematoda)
   4. Sponges (Porifera)
2. Level of Organization: Organ System
   Germ layers: three
   Symmetry: bilateral
   Cephalization: present
   Body Cavity: pseudocoel
   Segmentation: absent
   Digestive system: Separate mouth and anus
   Circulatory System: absent
   Respiratory System: absent
   Nervous System: head ganglia with dorsal and ventral nerve cords; ganglia in segments, some fused
   Reproduction: sexual (some hermaphroditic)
   Support: hydrostatic skeleton
   Note: internal fertilization, thin bodies don't need circulatory/respiratory system
   1. Roundworms (Nematoda)
   2. Segmented Worms (Annelida)
   3. Sponges (Porifera)
   4. Flatworms (Platyhelminthes)
3. Level of Organization: Organ System
   Germ layers: three
   Symmetry: bilateral
   Cephalization: present
   Body Cavity: Coelom
   Segmentation: absent
   Digestive system: Separate mouth and anus
   Circulatory System: open
   Respiratory System: gills and lungs
   Nervous System: well-developed brain in some cephalopods; several paired ganglia, most in the head; nerve network in the body wall
   Reproduction: Sexual (some hermaphroditic)
   Support: Hydrostatic skeleton
   Note: have muscular goot and mantle; include gastropods, bivalves, cephalopods
   1. Segmented Worms (Annelida)
   2. Sponges (Porifera)
   3. Roundworms (Nematoda)
   4. Snails, Clams, Squid (Mollusca)

2 True/False Questions

1. Flatworms (Platyhelminthes) → Level of Organization: Organ System
   Germ layers: three
   Symmetry: bilateral
   Cephalization: present
   Body Cavity: absent
   Segmentation: absent
   Digestive system: gastrovascular cavity
   Circulatory System: Absent
   Respiratory System: absent
   Nervous System: head ganglia with longitudal nerve cords
   Reproduction: Sexual (some hermaphroditic) asexual (body splits)
   Support: Hydrostatic skeleton
   Note: only one body opening (mouth), tissues group into functional units like eyespots

   True        False

2. Insects, Arachnids, Crustaceans (Anthropoda) → Level of Organization: Organ System
   Germ layers: three
   Symmetry: bilateral
   Cephalization: present
   Body Cavity: Coelom
   Segmentation: absent
   Digestive system: Separate mouth and anus
   Circulatory System: open
   Respiratory System: gills and lungs
   Nervous System: well-developed brain in some cephalopods; several paired ganglia, most in the head; nerve network in the body wall
   Reproduction: Sexual (some hermaphroditic)
   Support: Hydrostatic skeleton
   Note: have muscular goot and mantle; include gastropods, bivalves, cephalopods

   True        False