Invertebrate Chordates

Question 1

What phylum do lancelets and tunicates belong to?

Answer 1

Phylum Chordata

Question 2

Lec: Marine animals that are
formerly considered a subphylum of chordates, based on their possession of gill slits
and a rudimentary notochord.

Answer 2

Hemichordates

Question 3

Lec: A buccal diverticulum found in Hemichordates.

Answer 3

Stomochord

Question 4

Lec: Hemichordates are chordates. (TRUE OR FALSE)

Answer 4

FALSE

Question 5

Lec: 2 classes of Hemichordates.

Answer 5

Enteropneusta (acorn worms)
Pterobranchia

Question 6

Lec: Invertebrate organisms that are part of chordates. Includes the lancelets and the tunicates.

Answer 6

Protochordates

Question 7

Lec: 2 classes of Protochordates

Answer 7

Urochordata
Cephalochordata

Question 8

Lec: Common name of Enteropneusta

Answer 8

Acorn worms

Question 9

Lec: 3 Distinct regions of the body of Enteropneusta

Answer 9

protosome, mesosome, and
metasome

Question 10

Lec: How many genera of Pterobranchia are known?

Answer 10

3

Question 11

Lec: Protochordates include only _______.

Answer 11

Invertebrate Chordates

Question 12

Lec: The anastomosing system found in Pterobranchs.

Answer 12

Coenecium

Question 13

Lec: Urochordata is formerly known as ________.

Answer 13

Tunicata

Question 14

Lec: Other term for urochordates. Give an example.

Answer 14

Tunicates
Sea squirts

Question 15

Lec: These are only present in the larval stage of urochordates.

Answer 15

Notochord and nerve cord

Question 16

Lec: Tunicate larvae are _______, while their adult form are _______.

Answer 16

Free-living/Free-swimming
Sessile/Attached to a substrate

Question 17

Lec: These are where the water enters and exits in tunicates, respectively.

Answer 17

Incurrent siphon & Excurrent siphon

Question 18

Lec: Vertical groove lined with both flagellated and mucous cells.

Answer 18

Endostyle

Question 19

Lec: It is small, eel-like, unprepossessing animals that spend much of their time
buried in sand.

Answer 19

Cephalochordata / Lancelets

Question 20

Lec: These are still present in adult lancelets.

Answer 20

Notochord, nerve cord, and gill slits/pharyngeal slits

Question 21

Lab: Other term of lancelets.

Answer 21

Amphioxus

Question 22

Lab: It is the non-living test of tunicates.

Answer 22

Tunic

Question 23

Lab: Tunic is made up of _______.

Answer 23

Cellulose

Question 24

Lab: Which organism does tunicate larva resemble to?

Answer 24

Tadpole

Question 25

Lab: Other term for incurrent siphon.

Answer 25

Oral siphon

Question 26

Lab: Other term for excurrent siphon.

Answer 26

Atrial siphon

Question 27

Lab: What does an endostyle produce? What is its function?

Answer 27

Films of mucus - adheres to food particles that are in the water and this mixture is then passed through the pharynx through the sweeping movement of the cilia (Ciliary action).

Question 28

Lab: How does water move through an amphioxus?

Answer 28

Water -> mouth -> endostyle -> pharynx (gill-slits) -> atrium -> atriopore

Question 29

Lab: A mass of pigment cells located at the anterior end of the nerve cord.

Answer 29

Eye spot

Question 30

Lab: A linear series of pigment cells lying along the ventral wall of the nerve cord. They may possibly serve as photoreceptors.

Answer 30

Ocelli

Question 31

Lab: A series of finger-like projections, lined with cilia, that lies on the inner lateral and dorsal walls of the oral hood.

Answer 31

Wheel organ

Question 32

Lab: Thin tentacle-like strands that hang in front of the mouth and act as sensory devices and as a filter for the water passing into the body.

Answer 32

Oral Cirri

Question 33

Lab: Dorsal nerve cord is not protected by bone but by a _________.

Answer 33

Simpler notochord

Question 34

Lab: It extends into the head; anteroposterior (“head to tail”) axis, is usually closer to the dorsal than the ventral surface of the animal.

Answer 34

Notochord

Question 35

Lab: Functions of notochord

Answer 35

(a) rigid structure for muscle attachment (b) structural support of the body (c) signalling and coordinating development

Question 36

Lab: Masses of muscle under the skin of lancelets.

Answer 36

Myomeres

Question 37

Lab: The longitudinal series of about 60 angularly shaped muscle segments.

Answer 37

Myotomes

Question 38

Lab: The connective tissue partitions separating the myomeres.

Answer 38

Myosepta

Question 39

Lab:A pair of integumentary folds that extend along the ventrolateral surfaces from the anterior pharyngeal region almost to the atriopore.

Answer 39

Metapleural fold

Question 40

Lab: 3 distinct characteristics of lancelets.

Answer 40

notochord, pharyngeal pouch (gill slits), and the dorsal hollow nerve cord