Platyhelminths Flashcards
1
Q
4 classes of platyhelminths
A
- turbellaria
- Cestoda
- monogenea
- Trematoda
2
Q
What are platyhelminths referred to as
A
Flatworms
3
Q
Characteristics of Platyhelminths
- symmetry
- lack
A
- bilaterally symmetrical
- lack coelom, circulatory system or specialized respiratory organs
4
Q
Class Turbellaria characteristics
- lifestyle
- habitat
- size
- epidermis
A
- free living
- Maine, freshwater, moist terrestrial
- less than 1cm
- epidermis is ciliated and typically contains a large number of secretory cells
5
Q
Dugesia sp.
- type
- known as
A
Turbellaria
Planarians
6
Q
Dugesia sp.
- nervous system arrangement
- does it have an anus
A
Diffuse nerve net
No anus
7
Q
Dugesia sp.
-movement
A
- moves like a fish
- move by muscular contraction waves along the ventral side (anterior to posterior). Possess circular muscles (forward) and longitudinal muscles (contract) and move in desired direction (looping)
8
Q
Dugesia sp.
- advantages of thin body
- disadvantages of body shape
- why more advanced than Hydra
A
- gas exchange by diffusion
- no circulatory system or gut cavity so have to wait to expel food until feeding is done
- flatworms have tissues organized into organs and organ systems and bilaterally symmetrical and have brain and sense organs
9
Q
Bdelloura sp.
- type
- habitat
- differences to Dugesia sp.
A
- Turbellaria
- Marine, commensal on book gills of horseshoe crab)
- shorter, wider, no auricle, pharynx in middle, nerve cords
10
Q
Class cestoda
- known as
- type of parasite
A
Tapeworms
Endoparasites
11
Q
Characteristics of Class Cestoda
- body divisions
- lack
A
- tapeworm body is divided into a scolex, a neck and a series of segments called proglottids
- outer body layer is nonciliated syncytium known as the tegument.
- as tapeworms do not have mouths or digestive systems, the tegument is highly specialized for nutrient uptake
12
Q
Taenia solium (pork tapeworm)
- what’s on the scolex
- function of scolex
- what structures make up the major part of mature proglottid
A
- an anterior rounded side with suckers on lower edge and hooks at very top
- an anchoring organ that attaches to intestinal mucosa
- numerous testes and ovaries
13
Q
Class monogenea characteristics
- type of parasite
- attachment organ
- tegument
A
- ectoparasite of the skin or gills of fish
- haptor (opisthaptor) on posterior
- tegument forms the outer body wall
14
Q
Gyrodactylus sp.
- type
- habitat
- why so many hooks?
A
- monoangean
- freshwater on fish and frogs
- need to hold on to moving fish enough to parasitize
15
Q
Class-Trematoda characteristics
- also known as
- suckers
- tegument
A
- flukes
- well developed suckers that are located in the region of the mouth and on the ventral body surface
- tegument is nonciliated and syncytial
