Ch 17

Question 1

Acorn worms are members of the class

Answer 1

Enteropneusta

Question 2

Which of the following is not a characteristic of members of the phylum Hemichordata?

Answer 2

postanal tail

Question 3

Members of the class ______ use ciliated tentacles in filter feeding; usually live in secreted tubes in asexually produced colonies; and possess an expanded, shield-like proboscis. They live in deep oceanic water of the Southern Hemisphere.

Answer 3

Pterobranchia

Question 4

All of the following are characteristics of members of the phylum Chordata except one. Select the exception.

Answer 4

dorsal contractile blood vessel or heart

Question 5

All of the following are unique to members of the phylum Chordata except one. Select the exception.

Answer 5

notochord

Question 6

Tunicates or sea squirts are members of the chordate subphylum

Answer 6

Urochordata

Question 7

All of the following are characteristics of tunicates except one. Select the exception.

Answer 7

oral cirri

Question 8

Which of the following chordate structures is a mucus-secreting, ciliated groove that is used for trapping food particles during filter feeding?

Answer 8

endostyle

Question 9

Cephalochordates circulate blood by

Answer 9

contractile vessels.

Question 10

Amphioxus is a lancelet in the subphylum

Answer 10

Cephalochordata.

Question 11

All of the following are true of lancelets except one. Select the exception.

Answer 11

Their notochord is restricted to the tail region.

Question 12

Which of the following is an opening to the outside of the body of a cephalochordate through which water exits the body after passing through pharyngeal slits?

Answer 12

atriopore

Question 13

The development of sexual maturity in a larval body form is called

Answer 13

paedomorphosis.

Question 14

Which of the following characters can be used to distinguish Urochordata from all other chordates?

Answer 14

pharyngeal basket

Question 15

Paedomorphosis may help explain the evolutionary origin of the ______ from the ______.

Answer 15

motile chordates/sessile ancestors

Question 16

The oldest chordate fossils date to about __________________ before present.

Answer 16

530 million

Question 17

Animals in the phyla Hemichordata and Chordata share deuterostomate characteristics with echinoderms.

Answer 17

True

Question 18

A tornaria larva is planktonic. As it matures, it settles to the substrate and grows into an adult pterobranch.

Answer 18

False

Question 19

The pharyngeal slits were used by earliest chordates for gas exchange. In many later chordates, they have become adapted for filter feeding.

Answer 19

False

Question 20

Larval tunicates are planktonic and tadpole-like. Even though the adult tunicates are initially difficult to recognize as members of the phylum Chordata, the larvae possess all four unique chordate characteristics.

Answer 20

True

Question 21

The notochord of members of the subphylum Cephalochordata is unique in that it is partly composed of muscle cells and is somewhat contractile.

Answer 21

True

Question 22

The oral siphon of a tunicate carries water, undigested food wastes, and gametes out of the tunicate’s body.

Answer 22

False

Question 23

The atrium of cephalochordates is a diverticulum off the gut that extends anteriorly. It ends blindly and secretes digestive enzymes.

Answer 23

False

Question 24

Hemichordates, echinoderms, and chordates share structures that indicate that they most likely share a diploblastic or triploblastic ancestor.

Answer 24

True

Question 25

The notochord, postanal tail, and endostyle are important characteristics that distinguish the Hemichordata and Chordata.

Answer 25

True

Question 26

The endostyle is transformed into the adrenal gland when a larval lamprey metamorphoses into an adult.

Answer 26

False

Question 27

Cephalochordates are filter feeders.

Answer 27

True