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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. |