Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Ch. 27 Worms and Mollusks (pg. 682) 27-1 Flatworms Worms have a _________________________________ body Move_______________________________ rather than ____________________ Most have _____________________________________ at anterior end Allows worms to: ______________________________________________ A.What is a Flatworm? (Phylum ________________________) Size: ______________________________________ Flatworms are ________, ____________ worms that have _____________ and _________________________. They are the simplest animals to have 3___________ ________________, _________________________ and _________________________. Acoelomates – Coelom – No _____________ forms between the tissues of flatworms. The _______________________ is the only body cavity. B. Form and Function in Flatworms Because bodies are _______, all flatworms rely on _______________ for some essential body functions such as:_________________________________ Free-living flatworms have organ systems for:_____________________________ Parasitic flatworms are ______________ in structure 1. Feeding Free-living flatworms can be _______________ or _______________ Have a digestive cavity with a ____________ opening Pharynx – Parasitic worms feed on: ______________________________________________ Most do NOT need a _________________________________________ Because: 2. Respiration, Circulation, and Excretion Many flatworms rely on _______________ to transport ______________________ and to remove ________________________________ Excretion Flame cells – They may also filter and remove: Many flame cells are joined together to form:_________________________ that empties:___________________________________________________ 3. Response ganglia – In free-living flatworms: Eyespot – Other: Parasitic flatworms have: Because: 4. Movement Free-living flatworms move in 2 ways: 5. Reproduction Sexual reproduction – Most free-living flatworms are: hermaphrodite – Process: Asexual reproduction fission Parasitic flatworms often have: C. Groups of Flatworms – Enormously divers group 1. Turbellarians (Class ________________) Turbellarians are _______-___________flatworms. Most live in _________ or __________ water. Most are _________________, living in: _________________________________ Most are _____________________, the “_______________” freshwater worms 2. Flukes (Class ___________________) Flukes are ______________ flatworms. Most flukes infect the ______________ ________________ of their host. Schistosoma mansoni life cycle (pg. 687; Fig. 27-5): Primary host (in which it reproduces sexually) is the ________________ Intermediate host (where parasite reproduces asexually) is the __________ 1) Blood flukes infect humans by: Once inside they are carried to: Where they: The embryos are: 2) If they get in water, embryos develop into: And infect: 3) New larva, from asexual reproduction: Causes: _________________________ Problems: 3. Tapeworms (Class ____________________) Tapeworms are ________, _________, _____________ worms that are adapted to ___________________________________________________________________. They have NO _______________________ They are surrounded by: Structure: Scolex – Used to: Proglottids – Mature proglottids contain both: ____________________________________ Testes – After eggs are fertilized: If food or water contaminated with tapeworm zygotes is consumed by cows, fish, etc. (intermediate hosts): If a human eats incompletely cooked meat with cysts: 27-2 Roundworms (Phylum __________________) Among most numerous of all animals A. What is a Roundworm? Roundworms are ______________ worms that have ________________ and digestive systems with ___________________________________________ Size: Found: Pseudocoelum – Digestive tract with _____ openings - _______- within-a-______ body plan Food moves in ________________________ through the digestive tract Anus – B. Form and Function in Roundworms 1. Feeding Many free-living roundworms are: Some soil-dwelling and aquatic forms eat: 2. Respiration, Circulation, and Excretion Exchange gases and excrete metabolic wastes: NO _____________________________ Depend on ____________________ 3. Response Simple nervous systems consisting of: 4. Movement Hydrostatic skeleton - 5. Reproduction – sexual Most have: Use __________________________________ Parasitic roundworms have: C. Roundworms and Human Disease Most are _________________ Phylum is better known for species that _________ their hosts, including ______ 1. Trichnosis-causing Worms Trichinella life cycle – 2 common hosts are ________ and ________ Adult worms: Female worms carrying fertilized eggs: These larvae: Larvae form: Completes life cycle when: Humans get by: 2. Filarial Worms Found: Live in: Transmitted from one host to another by: In severe infections: Causes: 3. Ascarid Worms Causes severe malnutrition in more than ______________________________ By: Ascaris lumbricoides life cycle (pg. 692: Fig. 27-10) 1) Humans ingest: 2) Eggs travel to: 3) Larvae enter: 4) Larvae are: 5) Eggs are released and: Related species affect: 4. Hookworms Today, as many as __________________________________ are infected Hookworm eggs hatch: If they find an unprotected foot: Travel through: There, they: D. Research on C. elegans (Caenorhabditis elegans) ________-___________ roundworms Feeds on: DNA was: Have traced __________________ and __________________ of each body cell Studying how: 27-3 Annelids (pg.694) Phylum _______________ Annelids are a distinct group probably closely related to: Evidence for this is: A. What is an Annelid? Annelids are worms with _________________ bodies. They have a true __________ that is lined with tissue derived from _____________. Septa – Most segments are ______________ but they may be ______________ to: Setae – Annelids have ________ - _________ - ___ - __________ digestive tract B. Form and Function in Annelids 1. Feeding and Digestion Range from ___________________ to ________________ Many annelids get their food using a ______________ In earthworms: Pharynx: Crop – Gizzard Food is absorbed: 2. Circulation Closed Circulatory System – Dorsal vessel: Ventral vessel: In each body segment: Dorsal vessel functions like: 3. Respiration Aquatic annelids breathe through: Gill – Land-dwelling annelids: 4. Excretion Cellular wastes containing _____________ eliminated by: Nephridia – Digestive waste: 5. Response Most have: Consisting of: Sense organs: 6. Movement Have 2 major groups of body muscles Longitudinal muscles: Circular muscles: Use setae: 7. Reproduction - most reproduce _________________ Some use _________________________ and have ______________________ Others are hermaphrodites: clitellum - C. Groups of Annelids 1. Oligochaetes (Class ______________) Ex. _____________________________ Oligochaetes are annelids that typically have ______________________ and Relatively few __________ compared to ________________. Most live in ___________________________________ Castings – 2. Leeches (Class ______________) Most live: Leeches are typically ____________________________ that suck the ___________ and ______________ of their _________. About ¼ of all leeches are: Body structure: Once a wound has been made: 3. Polychaetes (Class _________________) ex. _______________________________ Polychaetes are _____________________ that have __________, ______________ _________________ tipped with ___________. D. Ecology of Annelids Importance of earthworms In soil: In food chains: Marine annelids 27-4 Mollusks (pg. 701) A. What is a Mollusk? Mollusks are ________________ animals that usually have an ____________ or _______________ shell. Include:______________________________________________________________ Many mollusks share: _________________________________________________ Trochophore – Also a characteristic of ______________ indicating that these 2 groups may be _____________________ Molecular studies suggest that: B. Form and Function in Mollusks Like annelids, mollusks have true _________ surrounded by __________ tissue. They also have complex, interrelated __________________ that function together to _____________________________________________________. 1. Body Plan – The body plan of most mollusks has 4 parts: foot – different forms: mantle – shell – Has been reduced or lost in: visceral mass – 2. Feeding Mollusks can be _______________________________________________________ Snails and slugs feed using a: Radula – Octopi and some sea slugs use: Clams, oyster, and scallops: Siphon – 3. Respiration Aquatic mollusks: Land snails and slugs: 4. Circulation open circulatory system – Pathway: found in: Faster moving mollusks have: closed circulatory system – 5. Excretion 6. Response - Varies greatly Clams and other 2-shelled mollusks: Octopi and their relatives: 7. Movement 8. Reproduction Snails and 2-shelled mollusks: Tentacled mollusks and certain snails: Some mollusks: C. Groups of Mollusks Divided according to characteristics of the ________ and _________ 1. Gastropods (Class ________________) Includes: ________________________________________________________ Gastropods are _____________ or _________________ mollusks that move by using a ______________________ located on the __________ side. Snails: Land slugs and nudibranches: Some nudibranches: 2. Bivalves (Class _____________) Bivalves have _______________ that are held together by ______ or _______ _____________________. Include: _________________________________________________________ 3. Cephalopods (Class ________________) Includes: ________________________________________________________ Cephalopods are typically _________________ mollusks in which the head is attached to a ________________. The foot is divided into ___________or ______ D. Ecology of Mollusks