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Worm Phyla. Mr. Jeff Peterson. Worm Phyla. ALL WORMS: Invertebrates Reproduce Asexually and Sexually Sense organs and a brain Tissue < Organs < Systems Bilaterial Symmetry Narrow bodies without legs. Phylum Platyhelminthes. Flatworms They have 1 body opening.
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Worm Phyla Mr. Jeff Peterson
Worm Phyla • ALL WORMS: • Invertebrates • Reproduce Asexually and Sexually • Sense organs and a brain • Tissue < Organs < Systems • Bilaterial Symmetry • Narrow bodies without legs
Phylum Platyhelminthes • Flatworms • They have 1body opening. • Some reproduce asexually, others do so sexually. • Some are free living, but most are parasites that obtain food from their hosts.
Phylum Platyhelminthes • Planarians • NOT parasites, but it attacks animals smaller than itself. • Have eyespots • Live in water (free-living) • Known for ability to regenerate – ability to regrow body parts.
Phylum Platyhelminthes • Flukes • All are parasites • One can cause schistosomiasis
Phylum Platyhelminthes • Tapeworms • Use hooks to attach to intestines and then it absorbs food from the host’s digestive system. • They are parasites • Humans get from eating improperly cooked meat with larvae still in it. • Infect animals too (ex. Dogs)
Phylum Platyhelminthes • Tapeworms
Phylum Nematoda • Roundworms • Look like tiny strands of cooked spaghetti with pointed ends. • They have 2 body openings. • Have a one-way digestive system that is open at both ends (mouth and anus) • Most reproduce sexually • Some are parasites, but most are free-living.
Phylum Nematoda • Parasitic roundworms include: • Trichinella: • Humans get from eating undercooked infected meat. • Form new cysts in muscles – cause pain • Hookworm: • Most are blood-sucking parasites • Attach to host’s intestines using hooks
Phylum Nematoda • Hookworm
Phylum Nematoda • Other examples are filarial worms (cause elephantiasis) and ascarids. • Some roundworms are beneficial because they feed on insects that harm human property (crops) • One example is the c. elegans
Phylum Annelida • Segmented Worm: Bodies have many linked sections called segments. • One-way digestive system with 2 body openings. • Use setae (little bristles on their bodies) to hold on to soil and help move. • Reproduce sexually • Closed circulatory system: blood moves through blood vessels.
Phylum Annelida • Segmented Worms • Marine Worms: live in saltwater • Also known as polychaetes • Leeches: • Most are blood-sucking parasites • Can be used for medical purposes
Phylum Annelida • Segmented Worms • Earthworms • In the digestive system, the crop is used for storage and the gizzard is used to grind soil and other materials. • Improve soil • They get oxygen through their skin (diffusion) • They can produce eggs and sperm in one body so they are called hermaphrodites • Have small brains and nerves throughout their bodies