Question | Answer |
What 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 of them are___. | free- living organisms |
what 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. | plants, fresh |
Planarians can reproduce in two ways. What are they. | Sexually, and asexually |
___are parasites with a complex life cycle that requires more than one hoot. | Flukes |
Most flukes reproduce how? | sexually |
Flukes cause a disease that is potentially a fatal blood disease in humans. What is it? | Schistosomiasis |
___are parasites that live in the intestines of a host cell. | Tapeworms |
Tapeworms absorb food digested by the what? | host |
What do tapeworms produce that contains sperm and eggs? | body segments |
The fertilized eggs in Tapeworms pass out of the host's body and can enter through another__. | host |
Flatworms were probably the first animal to have what type of symmetry? | bilateral |
they were also the first to have___, nerves in the head region, and a___tissue layer that develops into the organs and systems. | senses, third |
Roundworms are also called___. | nematodes |
they are extremely abundant, live in a variety of______, and have two body openings-- a_____and an___ | environments, mouth and anus |
Roundworms appeared early in animal evolution, but scientists are not sure how they___. | evolved |
A lot of roundworms are plant and animal_____; roundworms can cause____in humans. | parasites, trichinosis |
Some roundworms are beneficial because they kill___. | other pests |
Roundworms are essential in developing healthy___. | soil |