chapter 40 section 2 Flashcards Preview

Biology > chapter 40 section 2 > Flashcards

Flashcards in chapter 40 section 2 Deck (11):
1

notochord

A notochord is a stiff, flexible rod of cells that runs
the length of the body near the dorsal surface of a
chordate

2

atriopore

An atriopore is an opening through which water
leaves the body of a lancelet

3

In most chordates, the function of the notochord is taken over by the

vertebral column

4

The gill chambers of aquatic chordates evolved from the

pharyngeal pouches

5

A lancelet feeds by

d. filtering food particles from the water that passes through its pharynx

6

. Unlike adult lancelets, adult tunicates

are usually sessile

7

List the chordate characteristics that lancelets have as adults

a notochord, a dorsal nerve cord, pharyngeal
pouches, and a postanal tail

8

How do lancelets use their tail?

Lancelets use their tail to swim weakly and to
wriggle backward into the sand.

9

What behavior do tunicates exhibit when touched?

They squirt out a stream of water when touched

10

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

11

How are most adult tunicates similar to sponges, and how are they different
from sponges?

Like sponges, most adult tunicates are sessile animals
that feed by filtering food from the water;
they are also hermaphrodites, as are most
sponges. Unlike sponges, tunicates have true tissues
and organs; water enters an adult tunicate
through a single opening, while it enters a sponge
through numerous pores