Flashcards in chapter 40 section 2 Deck (11):
A notochord is a stiff, flexible rod of cells that runs
the length of the body near the dorsal surface of a
An atriopore is an opening through which water
leaves the body of a lancelet
In most chordates, the function of the notochord is taken over by the
The gill chambers of aquatic chordates evolved from the
A lancelet feeds by
d. filtering food particles from the water that passes through its pharynx
. Unlike adult lancelets, adult tunicates
are usually sessile
List the chordate characteristics that lancelets have as adults
a notochord, a dorsal nerve cord, pharyngeal
pouches, and a postanal tail
How do lancelets use their tail?
Lancelets use their tail to swim weakly and to
wriggle backward into the sand.
What behavior do tunicates exhibit when touched?
They squirt out a stream of water when touched
How does the structure of a larval tunicate differ from that of an adult tunicate?
A larval tunicate has all four chordate characteristics,
but an adult tunicate has only one: a pouchlike
pharynx with slits