click below
click below
Normal Size Small Size show me how
gia mei(:
Blume Ch 12.3
| Question | Answer |
|---|---|
| _____ are invertebrates with soft bodies, bilateral symmetry, and three tissue layers organized into organs and organ systems. | Worms |
| Flatworms are usually parasites, but a few are _____ ______ organisms. | free living |
| __________ are free-living flatworms that feed on small organisms or dead bodies of larger organisms. | Planarians |
| Most planarians live under rocks, on _____ material, or in _____ water. | plant; fresh |
| Planarians can _________ asexually or sexually; they lay eggs. | reproduce |
| ______ are parasites with a complex life cycle that requires more than one host. | Flukes |
| Most flukes reproduce ________. | sexually. |
| Flukes cause ____________, a potentially fatal blood disease in humans. | schistosoma |
| _________ are parasites that live in the intestines of a host animal. | Tapeworms |
| Tapeworms absorb food digested by the ____. | host. |
| Tapeworms produce body ________ that contain sperm and egg. | segments |
| The fertilized eggs pass out of the host's body and can ___ another host. | eat |
| Flatworms were probably the first animals to have _________ symmetry. | bilateral |
| ______ and nerves in the head region, and a _____ tissue layer that develops into organs and systems. | Senses; third |
| Roundworms, also called _________ are extremely abundant, live in a variety of environments, and have two body openings--a mouth and an anus. | nematodes |
| Roundworms appeared ______ in animal evolution, but scientists are not sure how they evolved. | early |
| Many roundworms are plant and animal _________; roundworms can cause trichinosis in humans. | parasites |
| Some roundworms are beneficial because they kill _____. | pests. |
| Roundworms are essential in developing healthy ____. | soil. |