Phylum Platyhelminthes Flashcards
Platyhelminthes embryonic tissue layers
Ectoderm
Mesoderm
Endoderm
3rd tissue layer between epidermis and digestive cavity
Mesoderm
Function of mesoderm
allows for development of muscle layers in body wall
allows for more elaborate organs, specialization, and greater division of labor than in cnidaria
The only internal space
digestive cavity
Advantages of flat body
allows them to rely on diffusion for exchange of gasses, nutrients, and wastes
Acoelomate
no body cavity
what does embryonic tissue ectoderm turn into
epidermis
what does embryonic tissue mesoderm turn into
Parenchyma
what does embryonic tissue endoderm turn into
Gastrodermis
The 2 layers surrounding body wall
Circular muscle
Longitudinal muscle
Feeding and Digestion
Carnivores
Endoparasites
Incomplete digestive tract
Respiration
No respiratory system
Gas exchange through flattened body wall
Excretion
Wastes like ammonia eliminated via diffusion through body wall
Other primitive systems include protonephridia
Asexual reproduction
Fission
Regeneration
Budding
Polyembryony
Sexual reproduction
Hemaphraditic