BY 124 SI Worksheet 6 (ch 33)

Multiple Choice & Short Answer

1. Which of these can be observed in the mesohyl of various undisturbed sponges at one time or another?1. Amoebocytes2. Spongine3. Zygotes4. Spicules5. Choanocytes

a. 1 onlyb. 1 & 2c. 1, 2, 4d. 1, 2, 3, 4e. All fivef.

2. A radially symmetrical animal that has two embryonic tissue layers probably belongs to which phylum?a. Porifera- no symmetryb. Cnidaria

c. Platyhelminthes- bisymmetric, triploblastic, acoelemates d. Nematoda- bisym, triblas, pseudocoelemates e. Echinodermata – bisym, tripbl, coelemates

3. Which of the following is true of members of the phylum Cnidaria?a. They are not capable of locomotion because they lack true muscle tissue- they lack true

muscle, but not all are incapable of locomotion (ctenophores have cilia to move)b. They are primarily filter feeders- some, not all are filter feedersc. They are the simplest organisms with a complete alimentary canal- they don’t have an

alimentary canald. They may use a gastrovascular cavity as a hydrostatic skeleton

4. Describe the life cycle of a hydozoa.

5. Describe some of the characteristics (feeding, movement, reproduction when applicable) of the Porifera, Hydrozoa, Scyphozoa, Anthozoa, and Ctenophora.

Porifera are sessile, filter feed, reproduce through budding or by dispersing sperm into water and then it ending up making into another sponge where it makes a zygoteHydrozoa are motile (but only in medusa stage), feed though filter feeling (usually in colonies), and reproduction is talked about aboveScyphozoa (jellies) are control-less movers, predatory though stinging, no polyp stage, don’t worry about reproAnthozoa- medusa stage only, sessile, filter feeders, no applicable reproducitionCtenophora- uncontrolled movement, trap prey with sticky tenticles, no applicable repro

6. Describe the characteristics (feeding, movement, reproduction) of planarians and contrast these characteristics with Trematodes and Tapeworms.

*all are Phylum Platyhelminthes

Planarians are free living flatworms that live in marine & fresh environments, move by cilia, prey on smaller/dead animals, reproduce asexually by fission or sexually

Trematodes are parasitic, require intermediate host (schistosomiasis)

Tapeworms live inside the host, (scolex) no mouth or gastrovascular cavity (feed by diffusion), have proglottid