Phylum: Platyhelminthes Flashcards
What is the phylum of all flatworms?
Platyhelminthes
What is the body like?
usually dorsoventrally flattened
Does it have a body cavity?
No, it is acoelomate (lack a body cavity)
What is the symmetry?
bilaterally symmetrical
Are they segmented?
They are unsegmented worms (members of class Cestoidea are strobilated)
What is the nerve system like?
somewhat cephalized with an anterior cerebral ganglion and usually longitudinal nerve cords.
What is the excretory/osmoregulatory structures?
Protonephridia
What is the excretory/osmoregulatory structures?
Protonephridia
What is the sexual reproduction?
Most are monoecious; complex reproductive systems
What does the nervous system consist of?
pair of anterior ganglia with longitudinal nerve cords connected by transverse nerves and located in the mesenchyme.
What is the class that includes Planaria
Turbellaria
What are the characteristics of the class Turbellaria?
mostly free-living and aquatic, external surface usually ciliated; possess rhabdites, protrusible proboscis, frontal glands; example is Planaria
What is the class that includes Flukes?
Trematoda
What are the characteristics of the class Trematoda?
all are parasitic, several holdfast devices present; have complicated life cycles involving both sexual and asexual reproduction. More than 10,000 species; example are Flukes
What is the class that includes tapeworms?
Cestoidea
