Postlab 2 - Protochordates and the Origin of Craniates

Question 1

characteristics of protochordates

Answer 1

1. bilateral symmetry
2. pharyngeal slits
3. notochord
4. dorsal hollow CNS
5. postanal tail
6. endostyle

Question 2

subset of the larger group of animalia and share common features in development

Answer 2

basal deuterostomes

Question 3

• Cambrian to present
• starfish, sea urchins, sea cucumbers, sea dasies, and crinoids
• presence of calcium carbonate skeleton
• presence of a secondary radial symmetry except in the most basal members

Answer 3

Echinoderms

Question 4

proposed the establishment of Phylum Chordata

Answer 4

Ernst Haeckel (1874)

Question 5

Different classes under Urochordata

Answer 5

1. Ascidiacea
2. Larvacea
3. Thaliacea

Question 6

sea squirts

Answer 6

Ascidiacea

Question 7

larvaceans

Answer 7

larvacea

Question 8

thaliaceans

Answer 8

thaliacea

Question 9

lancelet or amphioxus

Answer 9

cephalochordata

Question 10

• acorn worms
• marine organisms that live in the mud under shallow waters; fragile when handles; 1.5 m
• with invertebrate and chordate features

Answer 10

hemichordates

Question 11

added acorn worms to Phylum Chordata

Answer 11

Bateson (1884)

Question 12

why did Bateson add acorn worms to Phylum Chordata

Answer 12

1. dorsal, hollow NS
2. gill slits
3. stomochord

Question 13

• short diverticulum of the gut
• not homologous with the notochord

Answer 13

stomochord

Question 14

parts of the acorn worm

Answer 14

1. proboscis
2. collar
3. trunk

Question 15

different parts of acorn worm trunk

Answer 15

1. branchiogenital
2. hepatic
3. abdominal

Question 16

• marine chordates
• notochord is confined to the locomotor tail of the free-living larval stage and lost during metamorphosis into sessile adults
• encolsed within a delicate, nonliving, and colored transparent tunic
• filter feeders
• possess pharyngeal slits

Answer 16

urochordata

Question 17

Superclass under Subphylum Vertebrata

Answer 17

1. Pisces
2. Tetrapoda

Question 18

Classes under superclass Pisces

Answer 18

1. Agnatha
2. Placodermi
3. Chondrichthyes
4. Acanthodii
5. Osteichthyes

Question 19

Subphylum Cephalochordata:

• all trunk; muscle segments that lie just under the skin
• myomeres extend the entire length of the organism

Answer 19

locomotor musculature

Question 20

Subphylum Cephalochordata:

Skin

Answer 20

• single layer epidermis
• thin dermis
• cutaneous respiration

Question 21

Subphylum Cephalochordata:

• opens into the atrium which surrounds the pharynx laterally and ventrally
• water that enters the pharynx is another source of oxygen

Answer 21

pharyngeal slits

Question 22

Subphylum Cephalochordata:

• extends from tip to the rostrum to the tip of the tails
• muscular disc arranged like a long roll of coins separated by fluid-filled spaces
• adaptation that facilitates burrowing in the sand

Answer 22

notochord

Question 23

what does the notochord support in Subphylum Cephalochordata

Answer 23

1. pharyngeal bars
2. buccal cirri
3. mid-dorsal fin-like ridges

Question 24

Subphylum Cephalochordata:

what lines the central canal

Answer 24

ependymal cells

Question 25

Subphylum Cephalochordata: surrounds the brain and spinal cord

Answer 25

leptomeninx

Question 26

Subphylum Cephalochordata: Food processing organs

Answer 26

1. vestibule 2. wheel organ 3. buccal cirri

Question 27

Subphylum Cephalochordata: creates a steady flow of water through the mouth and into the pharynx

Answer 27

cilia

Question 28

Subphylum Cephalochordata: collective chamber of seawater

Answer 28

vestibule

Question 29

Subphylum Cephalochordata: covered with sticky mucus; retrieves some of the heavier food particles which directs it to the mouth and pharynx

Answer 29

wheel organ

Question 30

Subphylum Cephalochordata: partially strain water as it enters the vestibule

Answer 30

buccal cirri

Question 31

monitor the food that enters

Answer 31

chemoreceptors

Question 32

Subphylum Cephalochordata: not prominent cavity in adult

Answer 32

coelom

Question 33

Subphylum Cephalochordata: termination of venous system; beginning of arteries; not a pump

Answer 33

sinus venosus

Question 34

Subphylum Cephalochordata: Organs associated with eliminatio of metabolic waste

Answer 34

1. cyrtopodocytes 2. pedicels 3. nephridial tubule 4. flagellum

Question 35

Subphylum Cephalochordata: cells that collect the metabolic waste

Answer 35

cyrtopodocytes

Question 36

Subphylum Cephalochordata: footlike projections that make contact with an adjacent glomerulus (arterial rete)

Answer 36

pedicels

Question 37

Subphylum Cephalochordata: collects fluid from a cluster of cyrtopodocytes and empty into the atrium

Answer 37

nephridial tubule

Question 38

Subphylum Cephalochordata: from cyrtopodocyte that propell tubule fluids to the atrium

Answer 38

flagellum

Question 39

Subphylum Cephalochordata: bulge into the atrium into which sperm or egg are shed

Answer 39

gonads

Question 40

Subphylum Cephalochordata: how are gametes flushed into the sea

Answer 40

via atriopore

Question 41

ovaries and testes do not develop n the same individual

Answer 41

dioecious

Question 42

Classes under Superclass Tetrapoda

Answer 42

1. Amphibia 2. Reptilia 3. Aves 4. Mammalia