Fichas
Platyhelminthes - flatworms, flukes and tapeworms
Fichas del conjunto (10)
- 1How is the phylum divided?- Neodermata = Monogea, Digenea, and Cestoda
- Turbellaria = flatworms - 2List the key body plan features of platyhelminthes.- bilateral
- triploblastic
- acoelomate
- unsegmented
- no circulatory system
- mouth and gut, no anus
- anterior brain and nerve cords - 3Describe the structural and ecological features of Turbellaria.- ciliated epidermis
- free-living flatworms
- freshwater, marine or moist terrestrial
- each species has a food niche - 4Describe the origins of parasitism in Neodermata.- began on vertebrate hosts
- first ecto then endoparasites
- use of secondary hosts evolved after divergence of trematodes and cestodes from monogea
- T and C = highly evolved = alternation of generations and hosts - 5Describe the structural and ecological features of Monogea.- ciliated larvae = oncomiracidia
- well developed opisthaptor
- swim to host attach and form neodermis
- hosts = fish - 6Describe the structural features of Cestoda. What are the two divisions?- scolex
- strobila = body without hear and neck
- made up of proglottids
- do not have gut
- Cestodarians
- Eucestodes - 7Describe the life cycle of cestodes.- eggs in faeces -> environment
- cattle/pigs infected by vegetation
- oncospheres hatch and penetrate intestinal wall -> muscle
- develop into cysticerci
- humans infected by meat - 8Describe the life cycle of Fascioliasis.1. unembryonated eggs in faeces
2. embryonate eggs in water
3. miracidia hatch, penetrate snail
4. different stages in snail
5. cercariae released from snail -> encyst on vegetation as metacercariae
6. ingested by mammals -> excyst in duodenum and migrate into biliary ducts - 9Describe the pathology of Schistosomiasis.1. sweet water snail
2. cercariae penetrate through pores, enter blood stream and develop into adult schistosomes
3. adults in liver migrate to digestive tract and mate, release eggs
4. eggs excreted in faeces/urine, hatch into miracidiae -> infect snail -> cercariae - 10What are acoels?- primitive flatworms
- unsure as to phylogeny
- no longer platyhelminthes?
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- Prelims Organisms Fichas sobre Platyhelminthes - flatworms, flukes and tapeworms , creado por Kirstin Latimer el 09/01/2016.
- Creado por
- Kirstin Latimer
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