Platyhelminthes Flashcards
A large clade that contains almost all tripblastic animals and these kinds of animals can be divided into two clades
Bilateria
3 clades of Bilateria
- Lophotrocozoa
- Excysozoa
- Deuterostomia
What is a protostome taxon that possess either a lophophore or a trocophore larva?
Lophotrochozoa
In lophotrocozoa, what is a crown of ciliated tentacles found near the mouth and is used for feeding and respiration?
Lophophore
In lophotrochozoas, what is a free-swimming larva with a ring of large ciliated cells in front of the mouth and is primarily used for locomotion but can be used in feeding
Trochophore
What consists of free-living and parasitic species where most are aquatic and terrestrial ones are limited to moist areas
Platyhelminthes
What kind of bodies do flatworms have?
Dorsoventrally flattened bodies
Do Platyhelminthes have a body cavity?
No, they are acoelomate
Order at which platyhelminthes host on an organims
First is invertebrates, final is vertebrate
What are the debates regarding the validity of platyhelminthes?
- No clear defining feature of all members of the phylum
- phylum is shown to be monophyletic
In platyhelminthes, which organisms have ciliated epidermis?
Free-living flatworms
In platyhelminthes, which organism have nonciliated epidermis?
parasitic flatworms
For free-living flatworms, how do they attach to surfaces?
dual-gland adhesive organs
what are rod-shaped sturctures that swell and form a protective mucous sheath that free-swimming flatworms attach to?
Rhabdites
For parasitic flatwroms, what do they have that has multiple nuclei in one cell membrane and the larve are ciliated and lose the cilia once a host is contacted and it is resistant to immune response?
Syncytial tegument
Free-living flatowrms are either what?
predators or scavengers
Parasitic worms feed on?
Host tissues
Most flatworms have an incomplete what?
Incomplete digestive system
What do flatworm intestines have?
3 multi-branced trunks
What kind of digestion do flatworms have?
extracellular
What group of flatworms lack a digestive system therefore rely on the hosts digestive system?
Tapeworms
What is the excretory system of flatworms made of?
Photonephridia
In photonephridia, what are flagellated cells that line the tubules and direct waste?
flame cells
What systems do flatworms lack?
Respiratory and circulatory system
How is gas and nutrient exchange faciliated in flatworms?
diffusion and intercellular junctions
What system do flatworms have that are simple with longitudinal nerve cordsw with transverse nerves forming a “ladder” pattern?
Nervous system
In faltworms, where can a large concentration of nerve cells be found ?
Anterior end with sensory cells
Most flatworm species are what?
Monoecious/hermaphroditic
How do flatowrms reproduce?
Internally (hermaphroditic) or fission
What do some flatworm species engage in where 2 worms fight and attempt to stab each other with their penis to inseminate?
Penis fencing
True or false:
parasitic flatworms have varied life cycles
True
What class of flatworm is mostly free-living, inhabit marine, freshwater, and moist terrestrrial habitats, and their intestines can either have 3 or more branches?
Turbellaria
In Turbellaria, how do smaller planarians move?
swim with their cilia
In Turbellaria, how do larger and terrestrial planarians move?
crawl with muscular undulations
What flatworm class are internal parasite, their life cycle involves a primary host and one or more secondary hosts?
Trematoda
What is the priamary host of trematoda?
Mollusk
What is the secondary host of trematoda?
vertebrates
What kind of trematode lives in infested water and can cause several diseases?
Schistosoma
What do schistosoma trematodes cause?
Schistosomiasis
Where is schistosomiasis more common in?
tropical and subtropical countries with poor water quality and sanitation
What kind of trematoda is common in many east asian regions and inhabit the bile ducts of himans and other mammals?
snail to fish to mammal
Liver flukes
What flatworm class are paraisitic, attach to hosts’ posterior attachment organ with hooks on the external (of fish), and only have one host in its whole life time?
Monogenea
In monogenea, what is the posterior attachment that they attach to on their host?
Opisthaptor
What flatworm class are internal paraistes that live in the digestive tract of the vertebrate host and need at least 2 hosts?
Cestoda
What kind of bodies do cestoda (tapeworms) have?
long flattened bodies
In tapeworm bodies, what is a structure with hooks and suckers for attaching to the host’s gut and is a modification of the posterior end; not a head?
Scolex
In tapeworm bodies, what are segments that faciliate reproduction where when they mature, they detach and are passed in the feces of the host and contain both male and female reproductive system?
Proglottids
What is a chain of proglottids called?
Strobila
Do tapeworms have a digstive system?
no
Are tapeworms’ nervous and excretory systems similar to other flatworms?
yes
What do adult tapeworms lack? what do they have instead?
External cilia; microtriches
How do tapeworm infects humans?
consumption of poorly cooked or uncooked pork, beef, fish
what tapeworm is the most common in humans and juveniles live in intramuscular tissue of cattle and the adults live in the human intestine and can reach up to 10m up?
Beef tapeworm
What tapeworm is also common and the larvae develop in pig muscles then infect human intestines and if fertilized eggs are directly ingested by humans, larvae may infect the brain, spinal cord, liver, muscles, or eyes?
Pork tapeworm
What tapeworm has immature stages that develop in fish or crustaceans, mature individuals live in mammal intestines
Fish tapeworm
