6: Chordata part 1

Question 1

5 key chordate characteristics

Answer 1

• notochord
• dorsal hollow nerve chord
• pharyngeal gill slits/arches
• post-anal tail
• endostyle

Question 2

• mesoderm derived
• flexible rod-shaped structure found between digestive tube and nerve chord
• in all chordate embryos (some adult)

Answer 2

notochord

Question 3

• ectoderm derived
• hollow tube found dorsal to digestive tract and notochord
• develops into brain/spinal chord

Answer 3

dorsal hollow nerve chord

Question 4

• slits in pharynx that open to enviro
• allow water to exit during feeding
• become gill supports in fishes/components of ear, tonsils in tetrapods

Answer 4

pharyngeal gill slits

Question 5

• elongation of body extends beyond anus
• contain skeletal/muscles for movement (aquatic species)
• aid in balance/locomotion (terrestrial species)
• reduced in some species

Answer 5

post-anal tail

Question 6

• secrete mucus traps food particles/iodinated proteins
• give rise to thyroid glad in some species

Answer 6

endostyle

Question 7

3 chordate subphyla

Answer 7

urochordata
cephalochordata
vertebrata

Question 8

chordate subphyla:
- turnicates/sea squirts
- covered in tunic
- suspension feeders
- most monoecious
- larvae free-swimming; adults sessile
- adult lack notochord, dorsal hollow nerve cord, post-anal tail (in larva)

Answer 8

urochordata

Question 9

chordate subphyla:
- lancelets
- possess all chordate characteristics as adult
- notochord extends to head
- blade-like shape
- closed CS
- suspension feeder
- dioecious

Answer 9

cephalochordata

Question 10

urochordates are covered in a cellulose-like material called the ____

Answer 10

tunic

Question 11

in cephalochordates, the ______ ______ pumps blood in closed circulatory system similar to that of fish but w/o a heart

Answer 11

ventral aorta

Question 12

largest group of chordates; around 62,000 living species currently described

Answer 12

subphylum vertebrata/craniata

Question 13

vertrbrates have an ____ composed of bone/cartilage AKA they are _______

Answer 13

endoskeleton; musculoskeletal

Question 14

bone, cartilage, or fibrous structure that protects the brain

Answer 14

cranium

Question 15

• composed of several individual vertebrae joined together
• protects the spinal chord
• neural spines provide more area for muscle attachment

Answer 15

vertebral column/backbone

Question 16

vertebrate organ systems are modified to meet higher _______ _______

Answer 16

metabolic demands

Question 17

in vertebrate nervous systems, they have a ____ _____ and _____ _____ _____

Answer 17

tripartite brain; paired sensory organs

Question 18

3 parts of vertebrate tripartite brain

Answer 18

forebrain
midbrain
hindbrain

Question 19

nervous system structures unique to vertebrates develop from the _____ ____ and ____ _____

Answer 19

neural crest; ectodermal placodes

Question 20

fish division:
- lack jaws/fins
- no present-day jawless fish have armor

Answer 20

cyclostomata

Question 21

prehistoric cyclostomes called ____ had external bony armor

Answer 21

ostracoderms

Question 22

2 modern cyclostomes

Answer 22

myxini
petromyzontidae

Question 23

modern cyclostome:
- hagfish
- entirely marine
- almost completely blind
- tie bodies into knots for leverage
- generate slime when disturbed

Answer 23

myxini

Question 24

hagfish use _____ _____ on their tongues to feed

Answer 24

keratinized plates

Question 25

modern cyclostome: - lampreys - freshwater, marine

Answer 25

petromyzontida

Question 26

filter feeding petromyzontida larva resembles an _____

Answer 26

amphioxuz

Question 27

______ lampreys do not feed after metamorphosis

Answer 27

non-parasitic

Question 28

______ lampreys use keratinized teeth to break through flesh

Answer 28

parasitic

Question 29

chordate subphyla: - have jaws/paired fins

Answer 29

gnathostomes

Question 30

2 classifications of gnathostomes

Answer 30

chondrichthyes osteichthyes

Question 31

gnathostome classification: - cartilaginous fish - most marine, few freshwater - all predators, teeth w/ hard enamel - gill slits exposed

Answer 31

chondrichthyes

Question 32

fertilization in chondrichthyes is _____

Answer 32

internal

Question 33

cartilaginous fish include

Answer 33

sharks rays skates chimaeras/ratfish

Question 34

gnathostome classification: - bony fish - skin in overlapping scales

Answer 34

osteichthyes

Question 35

osterichthyes gills are covered by a muscular flap called the _____

Answer 35

opercukum

Question 36

2 bony fish

Answer 36

actinopterygii sarcopterygii

Question 37

bony fish: - ray-finned - fins have bones that resemble a fan

Answer 37

actinopterygii

Question 38

bony fish: - lobe-finned - fins are fleshy and lobed w bones resembling those of early tetrapods

Answer 38

sarcopterygii

Question 39

current living lobe-finned fish include these two

Answer 39

lungfish coelacanths

Question 40

current living lobe-fined fish; first appeared in devonian and diversified in mesozoic

Answer 40

coelacanth

Question 41

one genus of coelacanth still extant; "living fossil"

Answer 41

latimeria

Question 42

current living lobe-finned fish that has 3 surviving genera

Answer 42

lungfish