lecture 17 Flashcards
Most animals on earth belong to what clade?
Bilateria
What is a key feature of the Bilateria?
They posses bilateral systemtry
What is cephalization?
differentation of a head region
Are Bilateria cephalization?
They have varrying degrees, including anterior concentartion of neural ganglia ( brain)
What is a neural ganglia?
Brain
What type of embryos do Bilateria posses?
Triploblasic embryos.
are Acoela Bilateria?
Yes they are
What phylum do marine worms reside from?
Acoela
What us unique about Acoela?
They have no brain and they have no gut cavity.
What is a .worm?
General term for an animal with a body that lacks shell or elaborate appendages and usually longer than wide.
Where on the phylogentic tree would Acoela be in relation to the rest of the Bilateria?
Some molecular data places acoela as basal to the rest of the Bilateria
What are the four main characteristic of Lophotrochozoa?
- Some have lophophore
- Some have trochophore larva
- others have neither
- Main similarities are in DNA
How many phyla exist within Lophotrochozoa?
There are roughly 18
what Lophotrochozoa phylum contains flatworms?
Platyhelminthes.
What does the root word “platy” mean?
Flat
What does the root word “helminth” mean?
Worm
Flat worms have no fluid filled body cavity, what is this called?
Acoelomate.
Are flatworms triploblastic?
Yes they are.
How many species of Platyhelminthes are there?
roughly 20,000 spp
What are the two major classes of Platyhelminthes?
Class turbellaria
Class cestoidea
What is unique about the Turbellaria?
They are called the free-living flatworms.
- The epidermis of Turbellaria are covered in epidermal cilia.
Turbellaria have a pair of ___________ and ____________ near the front of their body.
Ventral nerve cords
and
pair of ganglia
Do turbellaria have an anal opening?
Nope
Are Turbellaria predatory?
Yes some are , mostly on other small metazoans.
What do NON-predatory Turbellaria feed on>
They feed on bacteria and protists, or decaying organic matter.
How do turbellaria reproduce?
PENIS FENCING.
They are hermaphroditic.
What class do tape worms reside from?
Cestoidea
Tapeworms are entirely ___________ in digestive systems of animals
endoparasitic
do tapeworms have a digestive system?
No, they digest their food through thin body walls.
What is the speciality organ that a tapeworm has that allows it to hold onto a hosts intestines
Scolex
What is the organ of a tapeworm that is devoted to reproduction? and where is it found?
after the SCOLEX comes a long chain of units devoted to reproduction called
- proglottids.
How are the eggs of Cestoidea implanted into Intermediate hosts?
They are eaten by the intermediate host.
How do the larvae of the Cestoidea get transported from the intermediate host into the final host?
The final host eats the intermediate host.
What is a final/definitive host?
Hosts in which a parasite engages in sexual reproduction
Can tape worms infect dogs? if so what are they?
Yes,
The Echinococcus granulosus infects herbivorous mammals as intermediate hosts to later infect dogs.
Once a Cestoidea tapeworm is in the tissue of a human, what do they do next?
Once they are in the tissues, larvae undergo asexual reproduction and split into thousands of new larvae that are located within a large -hydatid cyst.-
What dose the root word -Branch- mean?
Arm
What dose the root word -pod- mean
Foot
Phylum ___________ is one of four lophophore-bearing phylum.
brachiopoda
How do Brachiopoda feed? And what specialized oragan allows them to feed this way?
They suspension feed through the use of paired lophophores
True or false:
Brachiopda do not have complete gut and anal openings
False:
They do have complete gut and anal openings.
True or false:
Brachiopoda were far more diverse in the past having up to 30 000 spp compaired to modern counts of around 300 spp.
True
What do the root words -ecto- and -proct- mean?
Outside anus