Flatworms Flashcards
Define worm
A bilateral, elongate, invertebrate with no appendages
How are protosomes and deuterostomes distinguished?
By development
What are the 2 categories of flatworm
Free-Living and Parasitic
What is the defining feature for parasitic flatworms?
The syncytial tegument or neodermis
What allowed for more complex development in modern platyhelminthes?
Mesodermal-derived parenchyma
What are some unique features of class Turbellaria
Mostly free-Living worms
Mouth is on ventral side and leads to gut cavity
Live under objects in all environments
What 3 cells are present in the Dual-gland adhesive organ in worms, and briefly describe function
Viscid gland cells
Provide adhesive substance
Releasing gland cells
Release adhesive
Anchor cells
Secures a body to a surface
Explain longitudinal and circular muscles and their interactions in worms
Circular muscles elongate the body when contracted, and the longitudal muscles shorten the body, meaning the two are opposites of eachother
What is the function of the rhabdite in worms?
Swells up and forms a protective mucus sheet
What is the neodermis (tegument)?
Protects againt the digestive enzymes, and immune system of the host
Both absorptive and secretory
What is a bilboed ganglia? and why is it important for evolution?
A simple brain, kinda. Helps with complexity of body, as it allows for motor skills, and developed behaviours
What do statocysts and rheoreceptors do?
Helps maintain balance and detect water current
Define Monoecious
A complete male and female reproductive system in each proglottid
What are the 4 classes in the phylum platyhelminthes?
Turbellaria, Trematoda, Monogenea and cestoda
Which platyhelminthe class is not parasitic?
Turbellaria
