Ch. 14 Textbook Review Questions Flashcards
why is bilateral symmetry of adaptive value for actively motile animals
they are actively seeking food, shelter, and mates
In what ways are xenoturbellids similar to flatworms
morphological similarities
Match the terms:
Turbellaria
Monogenea
Trematoda
Cestoda
Endoparastic
Free-living and commensal
Ectoparastic
Turbellaria- freelving and commensal
Monogenea- Ectoparasitic
Trematoda- Endoparasitic
Cestoda - ectoparasitic
Describe the body plan of a typical turbellarian
sessile, radial symmetry, production of nematocysts.
Contrast a typical life cycle of a monogenean,with that of a digenetic trematode
monogenean life cycle: direct life cycle with a single host, eggs hatch to ciliated larvae, oncomiracidium, clings to host with hooks
Trematode Life cycle:
Requires a snail intermediate host, metacercariae encyst in fish muscle tissue, then fish is eaten by human
Describe and contrast the tegument of most turbellarians and the other classes of platyhelminths. Does the tegument provide evidence that trematodes, monogeneans , and cestodes from a clade within Platyhelminths? Why?
Turbellarians do not have a tegument but have a cellular, ciliated epidermis resting on a basement membrane. It contains rod-shaped rhabdites, which swell and form a protective mucous sheath around the body when discharged with water
most Turbellarians, adult members of Cestoda, Trematoda nad Monogenea have a nonciliated body covering called a Syncytial tegument.
Define each of the following with reference to cestodes: scolex, microtriches, proglottids, strobila
Scolex- holdfast structure wit suckers,hooks
microtriches- Minute projections, increase surface area
proglottids- reproductive units containing organs
strobila- proglottid chain
What characters unite members of clade Gnathifera
three phyla have similar small cuticular jaws
What is the normal size of a rotifer, where is it found, and what are its main features?
size- 3mm
found- in deep water, open ocean
features- ciliated crow, corona, beats looks like a rotating wheel
body- head, trunk, foot
Explain the difference b/t mictic and amictic eggs of rotifers. what is the adaptive value of each
Mictic eggs develop a thick, resistant shell and become dormant
Amictic eggs develop parthenogenetically into diploid females.
What is eutely?
fixed number of somatic cells
